This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADC16DV160_ADC input impedance matching circuit

Other Parts Discussed in Thread: ADC16DV160, LMK04808, ADC16DV160HFEB

HI

As per given ADC input equivalent circuit in the given below link for 1GHz, we simulated the circuit along with impedance matching circuit which is refereed from ADC16DV160 evaluation board schematic.

https://e2e.ti.com/support/data_converters/high_speed_data_converters/f/68/p/363442/1277594#1277594

ADC Part : ADC16DV160

Input frequency range is 1000 to 1100 Mhz.

Return loss is varied from -8.570 to -7.700dB (refer simulation result)

Impedance range is varied from 76 to 105 ohm.(refer simulation result)

Questions:

1. Pls confirm the given ADC input equivalent circuit is recommended for our operating frequency.

2. Kindly recommend the impedance matching circuit for 50 ohm matching and to meet the return loss below -15dB.


Note: find the attached schematic and simulation result for your reference.

 

ADC16DV160 Impedance match simulation- Results.pdfADC16DV160 Impedance match simulation- schematic.pdf

  • Hi Auxillian,

    The input network model was intended to cover up to ~250MHz and therefore the accuracy of the model and measurement method will likely reflect that. I suspect that the S11 measurement method was an SOLT de-embedding where the load was a surface-mount 50 ohm resistor to GND, so it is not the the best measurement up at higher frequencies. I doubt that a TRL S11 was performed. With that said, the accuracy of the model likely diverges at the higher frequencies (>250MHz) but I do not know the magnitude of the divergence. The input capacitance is cross referenced with the design, so that should be fairly accurate. The parasitic inductances will likely have sub-optimal modeling. I do not have strong confidence that this model is accurate enough to guarantee S11=-15dB @ 1GHz for your design by simulation.

    A 1st order target matching design would be to tune out the input capacitance with a shunt-differential inductor at the the ADC +/- input on the order of ~6nH. This should boost up the frequency response and improve the S11. Also, if you can handle some attenuation, you can consider putting a pi-attenuator just after the transformer which will improve the reflection coeff 1dB for every acceptable 1dB of loss.

    Also, it was not clear to me why you are using 27pF series caps in the signal path which is not an effective AC coupling capacitor at 1 GHz. Perhaps they tune the transformer?

    Regards, Josh 

  • Thank u for your reply.

    As per your suggestion, we included 6nH inductor at differential input with this there is improvement in return loss but insertion loss(-10dB) is very poor. So we have modify the circuit, by changing the inductor value from 6nh to 40nH, we got 6dB improvement in insertion loss and return loss is degraded which is affordable for our design .

    Can we go ahead of this approach?

    Can u mount this attached schematic discrete components on your development board and let you know the result?ADC16DV160 Impedance match simulation- Results 1.pdfADC16DV160 Impedance match simulation- schematic 1.pdf

    Note: find the schematic and result attachment for your review.

  • Yes, I think your results with the additional inductance will be fine

    Regards, Josh

  • Based on the earlier discussion, we are proceed the further layout routing design with existing schematic(File name: ADC16DV160 impedance match simulation-schematic) .

    But in the layout simulation with existing schematic, the return loss is come around (-9dB) is very poor. So we have tune the discrete component values, but there is no such a difference in the return loss. After changing the series resistor 10 ohm as a 4.7nH inductance, we get the good result in the return loss(refer the attachment)

    This series inductor 4.7 nH will create any problem ?

    Whether this attached layout routing is ok or not?

    Note: Kindly find the layout simulation with schematic and simulation result for your review.


    Regards

    James A

    ADC16DV160_Layout with schematic.pdfADC16DV160_simulation result.pdf

  • Addition to above Query posted by Mr.James, How to address "charge kick-back noise from the device"?

    1. Whether the attached simulation schematic will take care the charge kick back from device?

    2. We need to the match the Balun Input impedance to 50Ohms, Because it will be interfaced to Anti-Aliasing filters around 1GHz. If Balun un-balanced input is not matched to 50 Ohms with minimum Return loss of 15dB then the AAF (filter) response and pass-band amplitude ripple will be drastically changed due to impedance mismatch?

    Kindly check and confirm whether the attached ADC front-end circuit is taken care for charge kick-back and Impedance transformation to the ADC input at 1 to 1.1GHz analog input at sampling frequency of 160MHz.

    Regards,
    Sugumar K
  • Using series inductance between the ADC input and the termination resistors is going into uncharted territory as we have never looked at the performance with such a matching circuit. It is likely that the series inductance blocks the charge kickback transient (or causes a ringing effect) and the mismatch in the inductance value will cause a signal imbalance which may impact the even-order distortion. Intuitively, I would recommend splitting the capacitor in front of the ADC into sets: 1) a differential capacitor, 2) shunt capacitors to GND. This hopefully gives the common-mode component of the charge kickback a path to easily drain and settle.

    Regards, Josh

  • As you said charge kickback transients present at ADC input pins to be suppressed by using shunt & differential capacitors, We need the following inputs to freeze our Front-end circuit components,

    1. What is the charge kickback Transient pulse duration and amplitude at ADC input pins during sampling at 160MSPS?

    2.  As your ADC specification claims an analog full-power bandwidth of 1.4 GHz We have chosen your ADC for our analog RF input signal from 1000MHz to 1100MHz at sampling speed of 160MSPS.  We need the front-end shunt capacitor values  which can handle charge kick back noise as well as deliver optimum performance in the above mentioned RF input range.

    3.  As per above suggestions we have interchanged the Series inductor and shunt capacitors and done EM circuit co-simulation in ADS. But we are unable to achieve impedance matching with our front-end which contains 1:1 (50 Ohms) RF transformer part: B0322J5050AHF (Refer attached circuit and layout simulation).

    Review and kindly suggest a Front-end circuit for our above requirement and provide schematic simulation results if possible.

    Regards,
    Sugumar K

    1346.ADC16DV160 Impedance match simulation- schematic-R1.pdf3312.ADC16DV160 Impedance match simulation- Results -R1.pdf

  • We are also try to improve the Return loss and Insertion loss at ADC RF front end section by using optimization in ADS EM circuit Co-simulation.
    When we add a shunt inductor(4.3nH) to coupling capacitor(2.4pF) in unbalanced Balun port, We get the good result in Return loss (<14dB) and Insertion loss(<3dB).
    Herewith I have attached EM circuit co-simulation schematic and corresponding results. Kindly check and confirm as soon as possible whether we can proceed with the attached front-end circuit for our requirement.
    Note:
    To predict the Insertion loss of front-end section the equivalent circuit differential impedance is predicted (35-j*30 ohms) and used as output termination.
    The above impedance is applicable only around our operating frequency range of 1000 to 1100MHz only.Equivalent circuit schematic.pdfEquivalent Circuit result.pdfEquivalent termination schematic.pdfEquivalent termination result.pdf
  • Hi Joshua,

    We are awaiting for your response for the above Layout optimization circuit component values and results provided by Mr. James.

    Can we proceed with the above schematic for our operating frequency range of 1000 to 1100MHz?

    Regards,
    Sugumar K
  • Hi Joshua,

    Is there any update for our above updated layout simulation circuit and results?

    Also We need to confirm two things for our application,

    1. We need the confirmation for our impedance matching circuit based on our layout simulation and whether it will take care the Charge kick-back noise from ADC?

    2. Since the ADC is not yet validated above 500MHz, What is the ADC SNR performance at our operating frequency range 1000 to 1100MHz at 160MSPS sampling speed when -1dBFS and -65dBFS input levels?

    Regards,
    Sugumar K
  • Sugumar,

    I think the circuit looks OK. For the allowable capacitance at the ADC input, the spit between differential and shunt capacitance looks acceptable to suppress charge kickback. Obviously, more capacitance would be better from a performance perspective, but that creates a fundamental tradeoff between performance and BW and you need the bandwidth.

    Here is a reference plot for the SNR performance at 1GHz, -3dBFS which was measured on an EVM that I have handy. The SNR comes out to ~65 dBFS.

    The SNR for a -65dBFS input signal power will be very close to the baseline SNR=78dBFS.

    Regards, Josh

  • Hi,

    1. Are you used any front-end band-pass filter from your source for the above 65dBFS SNR measurement at 1GHz @-3dBFS input.

    2. What is the ADC sampling clock speed used for the above plot measurement at 1GHz?

    Regards,
    Sugumar K
  • Hi Sugumar

    I'm certain that Josh used a bandpass filter on the input signal and clock for that measurement.

    I'm not 100% sure what clock frequency he used, but I suspect it would be close to 160 MHz.

    Best regards,

    Jim B

  • Hi Jim/Josh,

    We have right now tested your ADC at our RF Frequency of 1090MHz at ADC sampling speed 160MSPS and we are able to achive only 53dB SNR at -3dBFS input signal to ADC.


    We are giving RF input signal from signal generator which is filtered through a Band-pass filter and feeded to ADC input and we are generating 160MHz sampling clock in our module using PLL jitter cleaner part: LMK04808 by using TCXO reference. We are not filtering the clock with band-pass filter in our circuit.

    I have attached our FFT results for our above measurements is for your reference.

    Also we request you to provide your ADC module circuit and exact clock frequency used for the above your measurements at 1GHz in which you have achieved 65dB of SNR.


    Regards,

    Sugumar K
  • Hi Sugumar

    Since he doesn't mention any modifications I believe Josh used the standard input network present on the ADC16DV160HFEB. Please take a look at the Evaluation Board User Guide in the product folder for the board.

    Best regards,

    Jim B

  • Hi Jim,

    In our ADC testing with input terminated to 50ohms condition, The first 5 LSB bits are toggling which is observed in the chipscope. Due to that we are unable to get expected Noise floor and SNR from ADC.

    Can you check in your Eval-board ADC16DV160HFEB and confirm how many LSB bits are toggling at input terminated condition at 160MSPS sampling speed.

    Regards,
    Sugumar K

  • Hi Jim,

    Is there any update for the above query?

    If possible request you to share the ADC data captured at input terminated condition for our comparison and proceed further.

    Regards,
    Sugumar K
  • Hi Sugumar

    With the EVM operating at 160MSPS I see noise of around 22 codes peak to peak. (this is toggling in the lowest 5 bits)

    22 peak to peak is equivalent to 7.78 codes RMS.

    7.78 codes in 65536 gives approximately -78.5 dB integrated noise which is within expectations for SNR for the ADC16DV160.

    Best regards,

    Jim B

  • Hi JIm,

    We have checked our ADC integrated noise at input terminated condition to 50 Ohms and sampling speed at 160MSPS.

    We can able to achieve the integrated noise level around 75.5dBFS whereas your results shows 78.5dBFS. We are lagging 3dB SNR level.

    Also we have attached the ADC count at input terminated condition for your reference.

    May I know the possible route cause for the ADC integrated noise increase in our module. How to improve further 3dB?

    Note: Our ADC Differential sinusoidal clock, fCLK= 160 MSPS at 2 Vp-p whereas your datasheet it is measured at 2.8 Vp-p. Will it have any impact in integrated noise level?

    Regards,

    Sugumar K

  • ADC_160MSPS_Input-TERM_count.txt
    -579
    -572
    -572
    -574
    -575
    -577
    -570
    -576
    -575
    -573
    -571
    -576
    -568
    -575
    -577
    -577
    -573
    -577
    -569
    -572
    -571
    -581
    -575
    -581
    -575
    -576
    -578
    -583
    -573
    -573
    -575
    -577
    -571
    -577
    -567
    -570
    -577
    -574
    -570
    -575
    -577
    -568
    -574
    -576
    -563
    -574
    -577
    -573
    -571
    -574
    -572
    -570
    -580
    -570
    -580
    -576
    -583
    -579
    -577
    -573
    -572
    -575
    -579
    -573
    -578
    -577
    -574
    -574
    -570
    -580
    -571
    -577
    -568
    -577
    -577
    -580
    -567
    -576
    -572
    -579
    -575
    -573
    -573
    -575
    -572
    -573
    -575
    -577
    -566
    -574
    -578
    -580
    -578
    -582
    -574
    -570
    -584
    -579
    -579
    -575
    -576
    -575
    -573
    -571
    -575
    -574
    -575
    -579
    -571
    -576
    -576
    -576
    -577
    -582
    -576
    -573
    -578
    -579
    -576
    -571
    -568
    -574
    -572
    -573
    -576
    -572
    -577
    -570
    -574
    -576
    -572
    -573
    -574
    -573
    -570
    -575
    -571
    -575
    -571
    -575
    -573
    -578
    -571
    -573
    -582
    -571
    -577
    -570
    -579
    -578
    -583
    -573
    -572
    -576
    -573
    -572
    -573
    -574
    -574
    -573
    -570
    -574
    -566
    -577
    -569
    -571
    -571
    -576
    -580
    -569
    -577
    -570
    -574
    -578
    -578
    -574
    -570
    -573
    -570
    -576
    -574
    -577
    -576
    -572
    -578
    -565
    -576
    -573
    -572
    -578
    -565
    -574
    -574
    -576
    -570
    -572
    -570
    -568
    -577
    -574
    -575
    -575
    -575
    -568
    -572
    -569
    -570
    -569
    -576
    -576
    -576
    -573
    -576
    -573
    -577
    -569
    -577
    -569
    -572
    -573
    -568
    -571
    -571
    -571
    -569
    -580
    -577
    -570
    -572
    -578
    -573
    -570
    -570
    -580
    -572
    -577
    -574
    -575
    -565
    -575
    -568
    -577
    -576
    -581
    -573
    -572
    -573
    -571
    -575
    -576
    -569
    -569
    -577
    -575
    -575
    -570
    -572
    -576
    -579
    -573
    -579
    -573
    -576
    -569
    -570
    -572
    -578
    -575
    -578
    -573
    -579
    -569
    -577
    -572
    -580
    -578
    -580
    -575
    -571
    -576
    -573
    -571
    -563
    -579
    -569
    -576
    -573
    -573
    -574
    -570
    -570
    -573
    -577
    -577
    -571
    -574
    -574
    -581
    -573
    -581
    -576
    -576
    -574
    -580
    -575
    -572
    -578
    -573
    -582
    -577
    -579
    -575
    -574
    -578
    -573
    -581
    -574
    -578
    -577
    -578
    -575
    -573
    -574
    -582
    -575
    -576
    -575
    -578
    -579
    -572
    -577
    -576
    -570
    -578
    -577
    -584
    -574
    -579
    -573
    -574
    -575
    -570
    -573
    -579
    -581
    -572
    -580
    -568
    -575
    -574
    -577
    -578
    -582
    -579
    -570
    -574
    -583
    -577
    -573
    -579
    -575
    -576
    -570
    -576
    -568
    -575
    -574
    -578
    -574
    -576
    -575
    -569
    -561
    -575
    -569
    -578
    -572
    -577
    -571
    -571
    -568
    -572
    -572
    -581
    -572
    -578
    -578
    -572
    -577
    -571
    -570
    -575
    -580
    -578
    -582
    -570
    -570
    -573
    -572
    -569
    -576
    -572
    -577
    -575
    -571
    -577
    -576
    -575
    -575
    -570
    -572
    -579
    -570
    -570
    -570
    -570
    -574
    -583
    -573
    -575
    -572
    -573
    -569
    -573
    -571
    -570
    -578
    -579
    -575
    -570
    -574
    -572
    -569
    -571
    -573
    -572
    -583
    -580
    -571
    -569
    -572
    -571
    -575
    -574
    -571
    -571
    -575
    -571
    -574
    -571
    -570
    -573
    -577
    -576
    -573
    -580
    -580
    -577
    -576
    -573
    -577
    -575
    -573
    -582
    -573
    -571
    -576
    -577
    -576
    -584
    -568
    -581
    -575
    -578
    -568
    -574
    -577
    -577
    -569
    -573
    -568
    -573
    -573
    -568
    -566
    -575
    -575
    -572
    -573
    -569
    -574
    -567
    -575
    -577
    -568
    -574
    -578
    -578
    -570
    -569
    -571
    -571
    -578
    -569
    -581
    -565
    -573
    -568
    -569
    -565
    -571
    -578
    -572
    -584
    -571
    -576
    -562
    -577
    -564
    -574
    -573
    -572
    -576
    -571
    -571
    -572
    -578
    -567
    -574
    -572
    -575
    -570
    -571
    -574
    -579
    -574
    -572
    -575
    -574
    -576
    -569
    -576
    -576
    -575
    -575
    -579
    -573
    -574
    -570
    -572
    -578
    -583
    -574
    -579
    -573
    -577
    -573
    -569
    -563
    -570
    -577
    -568
    -576
    -573
    -569
    -569
    -570
    -574
    -570
    -576
    -569
    -578
    -577
    -573
    -573
    -571
    -570
    -579
    -576
    -577
    -579
    -572
    -575
    -574
    -578
    -574
    -578
    -568
    -576
    -577
    -576
    -572
    -577
    -578
    -573
    -576
    -575
    -581
    -574
    -573
    -571
    -575
    -562
    -575
    -571
    -570
    -572
    -573
    -573
    -575
    -567
    -575
    -570
    -576
    -574
    -577
    -567
    -578
    -579
    -567
    -573
    -577
    -570
    -578
    -573
    -576
    -573
    -575
    -579
    -572
    -577
    -572
    -575
    -572
    -573
    -563
    -571
    -573
    -573
    -577
    -576
    -578
    -568
    -573
    -570
    -575
    -579
    -571
    -577
    -576
    -578
    -571
    -567
    -572
    -578
    -573
    -579
    -575
    -576
    -573
    -574
    -573
    -576
    -580
    -576
    -579
    -572
    -574
    -575
    -575
    -577
    -574
    -575
    -571
    -574
    -576
    -569
    -576
    -574
    -578
    -572
    -579
    -580
    -572
    -573
    -572
    -571
    -578
    -572
    -569
    -574
    -573
    -575
    -575
    -571
    -574
    -571
    -581
    -572
    -569
    -575
    -571
    -573
    -572
    -572
    -570
    -566
    -575
    -582
    -566
    -572
    -572
    -579
    -577
    -587
    -575
    -582
    -571
    -570
    -570
    -573
    -575
    -572
    -574
    -571
    -577
    -569
    -574
    -573
    -579
    -576
    -577
    -575
    -576
    -571
    -572
    -567
    -578
    -572
    -576
    -574
    -574
    -570
    -566
    -568
    -573
    -575
    -575
    -573
    -573
    -569
    -568
    -568
    -569
    -583
    -566
    -575
    -576
    -572
    -573
    -572
    -570
    -573
    -575
    -576
    -580
    -574
    -575
    -573
    -572
    -574
    -575
    -575
    -576
    -569
    -566
    -574
    -567
    -572
    -572
    -577
    -576
    -577
    -573
    -578
    -572
    -575
    -570
    -577
    -573
    -580
    -574
    -579
    -576
    -576
    -575
    -580
    -575
    -576
    -572
    -578
    -572
    -574
    -577
    -573
    -577
    -573
    -578
    -575
    -582
    -567
    -583
    -567
    -577
    -568
    -578
    -573
    -573
    -572
    -565
    -576
    -568
    -574
    -576
    -575
    -572
    -569
    -571
    -573
    -573
    -580
    -572
    -575
    -574
    -574
    -570
    -575
    -574
    -573
    -571
    -575
    -570
    -571
    -569
    -572
    -569
    -576
    -572
    -573
    -578
    -573
    -569
    -571
    -574
    -573
    -574
    -579
    -578
    -570
    -578
    -577
    -573
    -568
    -579
    -571
    -577
    -577
    -578
    -569
    -573
    -574
    -574
    -574
    -572
    -579
    -569
    -571
    -565
    -576
    -570
    -579
    -570
    -578
    -568
    -575
    -574
    -570
    -575
    -574
    -577
    -572
    -578
    -566
    -575
    -572
    -580
    -573
    -575
    -577
    -570
    -576
    -570
    -574
    -572
    -578
    -573
    -580
    -571
    -574
    -570
    -579
    -569
    -570
    -575
    -576
    -576
    -580
    -576
    -566
    -581
    -577
    -571
    -579
    -582
    -576
    -577
    -573
    -568
    -575
    -574
    -573
    -567
    -571
    -575
    -580
    -574
    -576
    -565
    -577
    -573
    -573
    -577
    -576
    -568
    -575
    -571
    -567
    -568
    -573
    -576
    -571
    -577
    -573
    -571
    -573
    -572
    -572
    -577
    -584
    -569
    -573
    -570
    -573
    -580
    -571
    -574
    -580
    -573
    -571
    -573
    -570
    -574
    -571
    -576
    -574
    -573
    -578
    -567
    -573
    -574
    -578
    -575
    -574
    -578
    -576
    -578
    -568
    -575
    -569
    -576
    -576
    -574
    -569
    -575
    -570
    -572
    -571
    -577
    -573
    -574
    -582
    -567
    -577
    -569
    -579
    -568
    -574
    -578
    -578
    -573
    -577
    -571
    -566
    -575
    -575
    -575
    -569
    -576
    -575
    -573
    -567
    -575
    -568
    -565
    -569
    -573
    -568
    -582
    -567
    -567
    -573
    -575
    -576
    -577
    -575
    -578
    -578
    -580
    -572
    -573
    -579
    -574
    -575
    -575
    -569
    -569
    -569
    -575
    -568
    -575
    -571
    -572
    -571
    -568
    -574
    -574
    -574
    -574
    -574
    -575
    -568
    -575
    -573
    -574
    -569
    -574
    -576
    -584
    -566
    -580
    -569
    -574
    -570
    -571
    -576
    -575
    -586
    -573
    -578
    -571
    -583
    -574
    -570
    -577
    -576
    -571
    -578
    -576
    -577
    -571
    -573
    -572
    -565
    -577
    -575
    -578
    -571
    -568
    -577
    -570
    -572
    -572
    -572
    -571
    -563
    -571
    -571
    -571
    -573
    -569
    -570
    -571
    -576
    -570
    -575
    -575
    -571
    -572
    -572
    -574
    -569
    -573
    -569
    -578
    -568
    -576
    -573
    -571
    -578
    -571
    -577
    -572
    -569
    -575
    -573
    -570
    -574
    -574
    -574
    -573
    -575
    -571
    -569
    -571
    -579
    -577
    -578
    -570
    -573
    -572
    -573
    -576
    -576
    -576
    -576
    -574
    -571
    -576
    -579
    -577
    -568
    -577
    -572
    -571
    -577
    -575
    -574
    -578
    -571
    -573
    -583
    -576
    -567
    -567
    -573
    -571
    -578
    -572
    -581
    -576
    -564
    -573
    -568
    -573
    -577
    -581
    -576
    -575
    -567
    -575
    -573
    -571
    -571
    -571
    -574
    -572
    -573
    -568
    -573
    -574
    -574
    -580
    -576
    -576
    -570
    -574
    -571
    -575
    -579
    -580
    -584
    -568
    -578
    -570
    -577
    -572
    -583
    -577
    -577
    -579
    -572
    -576
    -578
    -577
    -573
    -573
    -576
    -576
    -575
    -574
    -575
    -576
    -573
    -573
    -575
    -582
    -574
    -577
    -570
    -571
    -571
    -575
    -573
    -571
    -579
    -576
    -572
    -578
    -571
    -575
    -576
    -569
    -570
    -579
    -568
    -569
    -574
    -572
    -575
    -574
    -584
    -577
    -573
    -574
    -573
    -575
    -575
    -580
    -576
    -574
    -573
    -576
    -573
    -575
    -574
    -575
    -581
    -574
    -576
    -572
    -572
    -578
    -579
    -576
    -584
    -573
    -576
    -576
    -571
    -573
    -579
    -574
    -584
    -567
    -572
    -576
    -571
    -587
    -560
    -581
    -572
    -578
    -568
    -576
    -580
    -574
    -577
    -569
    -578
    -570
    -573
    -573
    -576
    -575
    -582
    -567
    -577
    -573
    -572
    -574
    -577
    -577
    -569
    -569
    -578
    -578
    -574
    -572
    -578
    -576
    -570
    -573
    -575
    -574
    -572
    -576
    -570
    -581
    -569
    -569
    -571
    -569
    -576
    -572
    -578
    -571
    -571
    -575
    -571
    -574
    -570
    -579
    -570
    -574
    -572
    -572
    -573
    -573
    -581
    -574
    -570
    -570
    -576
    -578
    -568
    -571
    -578
    -571
    -572
    -581
    -569
    -571
    -571
    -567
    -575
    -572
    -577
    -574
    -583
    -570
    -573
    -574
    -574
    -570
    -571
    -575
    -573
    -576
    -576
    -578
    -570
    -573
    -571
    -582
    -577
    -581
    -572
    -574
    -574
    -576
    -568
    -576
    -573
    -578
    -569
    -574
    -571
    -572
    -569
    -573
    -566
    -579
    -568
    -574
    -573
    -571
    -575
    -569
    -577
    -575
    -572
    -569
    -569
    -569
    -575
    -575
    -568
    -566
    -581
    -564
    -571
    -572
    -571
    -574
    -570
    -576
    -570
    -575
    -574
    -571
    -573
    -566
    -572
    -572
    -571
    -573
    -574
    -575
    -570
    -565
    -570
    -573
    -567
    -575
    -571
    -578
    -567
    -572
    -573
    -570
    -577
    -573
    -578
    -571
    -576
    -572
    -571
    -574
    -572
    -573
    -570
    -576
    -571
    -575
    -575
    -574
    -568
    -577
    -577
    -566
    -572
    -573
    -577
    -570
    -574
    -569
    -578
    -580
    -571
    -572
    -572
    -570
    -572
    -574
    -577
    -571
    -576
    -572
    -573
    -563
    -573
    -577
    -571
    -579
    -578
    -574
    -575
    -567
    -578
    -571
    -573
    -577
    -580
    -582
    -574
    -576
    -563
    -573
    -577
    -573
    -572
    -569
    -571
    -571
    -569
    -572
    -574
    -575
    -575
    -573
    -574
    -572
    -573
    -569
    -574
    -574
    -567
    -576
    -576
    -572
    -568
    -577
    -569
    -575
    -566
    -573
    -582
    -576
    -570
    -568
    -570
    -572
    -578
    -572
    -577
    -578
    -572
    -566
    -569
    -574
    -572
    -570
    -571
    -570
    -579
    -571
    -578
    -577
    -574
    -572
    -574
    -575
    -575
    -575
    -577
    -567
    -569
    -574
    -573
    -577
    -568
    -581
    -569
    -579
    -573
    -574
    -571
    -571
    -574
    -569
    -571
    -571
    -574
    -569
    -573
    -569
    -574
    -578
    -572
    -568
    -579
    -573
    -573
    -573
    -577
    -577
    -570
    -577
    -575
    -566
    -578
    -572
    -576
    -575
    -577
    -576
    -568
    -573
    -571
    -569
    -565
    -576
    -571
    -570
    -575
    -569
    -575
    -570
    -577
    -577
    -565
    -579
    -573
    -578
    -578
    -577
    -579
    -573
    -579
    -578
    -574
    -574
    -570
    -569
    -579
    -572
    -574
    -572
    -569
    -572
    -562
    -575
    -570
    -579
    -575
    -573
    -567
    -573
    -571
    -579
    -576
    -578
    -572
    -580
    -570
    -581
    -570
    -579
    -568
    -572
    -572
    -583
    -583
    -573
    -575
    -570
    -576
    -566
    -584
    -568
    -574
    -574
    -573
    -572
    -574
    -573
    -571
    -570
    -581
    -576
    -581
    -569
    -575
    -572
    -569
    -577
    -570
    -577
    -571
    -577
    -574
    -567
    -569
    -577
    -568
    -577
    -573
    -573
    -575
    -573
    -566
    -570
    -577
    -585
    -578
    -576
    -569
    -571
    -567
    -575
    -579
    -571
    -576
    -580
    -577
    -571
    -575
    -575
    -581
    -573
    -573
    -578
    -576
    -574
    -572
    -571
    -577
    -573
    -572
    -580
    -578
    -571
    -577
    -570
    -580
    -571
    -576
    -580
    -575
    -579
    -568
    -572
    -578
    -573
    -571
    -575
    -578
    -577
    -573
    -575
    -571
    -584
    -574
    -581
    -572
    -575
    -570
    -576
    -571
    -575
    -572
    -579
    -573
    -576
    -572
    -571
    -573
    -570
    -566
    -576
    -578
    -579
    -575
    -573
    -572
    -578
    -574
    -573
    -576
    -572
    -581
    -568
    -577
    -573
    -575
    -571
    -580
    -571
    -574
    -579
    -571
    -579
    -572
    -576
    -573
    -576
    -572
    -579
    -571
    -572
    -569
    -566
    -571
    -576
    -573
    -575
    -578
    -572
    -577
    -569
    -572
    -575
    -575
    -572
    -577
    -579
    -571
    -568
    -575
    -580
    -573
    -577
    -575
    -573
    -575
    -569
    -577
    -574
    -572
    -585
    -572
    -575
    -569
    -572
    -564
    -574
    -578
    -574
    -577
    -572
    -575
    -574
    -566
    -571
    -571
    -567
    -577
    -569
    -575
    -568
    -571
    -569
    -573
    -573
    -578
    -578
    -569
    -573
    -576
    -572
    -578
    -573
    -575
    -580
    -574
    -577
    -571
    -569
    -576
    -574
    -574
    -571
    -569
    -575
    -572
    -571
    -567
    -577
    -569
    -575
    -580
    -574
    -577
    -572
    -574
    -569
    -577
    -574
    -581
    -571
    -571
    -567
    -569
    -569
    -567
    -568
    -572
    -572
    -575
    -579
    -566
    -571
    -567
    -575
    -579
    -574
    -572
    -576
    -570
    -576
    -566
    -575
    -575
    -574
    -572
    -578
    -575
    -577
    -582
    -574
    -574
    -570
    -576
    -577
    -576
    -579
    -575
    -567
    -578
    -570
    -578
    -574
    -576
    -572
    -573
    -573
    -565
    -573
    -561
    -575
    -570
    -571
    -573
    -577
    -570
    -574
    -575
    -571
    -572
    -574
    -572
    -575
    -571
    -579
    -573
    -571
    -573
    -575
    -573
    -573
    -570
    -572
    -576
    -576
    -577
    -569
    -574
    -567
    -573
    -569
    -570
    -573
    -570
    -578
    -569
    -575
    -568
    -570
    -573
    -574
    -578
    -579
    -577
    -574
    -573
    -570
    -567
    -573
    -571
    -580
    -576
    -574
    -576
    -576
    -567
    -571
    -574
    -577
    -577
    -578
    -574
    -579
    -575
    -572
    -578
    -565
    -574
    -577
    -569
    -576
    -567
    -569
    -573
    -572
    -573
    -578
    -572
    -575
    -570
    -575
    -572
    -576
    -572
    -580
    -571
    -575
    -575
    -573
    -570
    -571
    -575
    -575
    -571
    -578
    -572
    -574
    -574
    -569
    -581
    -569
    -578
    -568
    -574
    -576
    -570
    -575
    -576
    -571
    -571
    -571
    -572
    -566
    -567
    -575
    -571
    -577
    -577
    -576
    -575
    -577
    -572
    -574
    -571
    -570
    -569
    -569
    -579
    -571
    -570
    -571
    -574
    -567
    -568
    -574
    -577
    -577
    -572
    -583
    -569
    -578
    -576
    -574
    -574
    -571
    -581
    -571
    -577
    -577
    -565
    -574
    -573
    -575
    -573
    -572
    -572
    -570
    -574
    -568
    -574
    -568
    -577
    -575
    -579
    -574
    -572
    -573
    -575
    -578
    -575
    -582
    -579
    -574
    -566
    -573
    -574
    -573
    -577
    -579
    -574
    -572
    -575
    -572
    -572
    -575
    -570
    -573
    -574
    -573
    -577
    -569
    -576
    -575
    -571
    -577
    -571
    -576
    -574
    -575
    -573
    -570
    -573
    -572
    -574
    -578
    -574
    -573
    -568
    -576
    -573
    -569
    -567
    -571
    -571
    -569
    -578
    -571
    -569
    -574
    -568
    -578
    -573
    -575
    -572
    -573
    -572
    -580
    -574
    -579
    -570
    -576
    -573
    -571
    -576
    -570
    -572
    -574
    -578
    -568
    -582
    -571
    -567
    -569
    -572
    -580
    -572
    -572
    -572
    -566
    -571
    -568
    -567
    -574
    -574
    -583
    -572
    -584
    -579
    -581
    -572
    -568
    -579
    -575
    -578
    -576
    -576
    -577
    -579
    -569
    -581
    -568
    -578
    -573
    -571
    -571
    -570
    -578
    -569
    -577
    -579
    -571
    -575
    -574
    -569
    -570
    -576
    -573
    -574
    -572
    -577
    -574
    -572
    -571
    -571
    -577
    -569
    -573
    -578
    -578
    -575
    -575
    -566
    -575
    -578
    -574
    -569
    -573
    -575
    -576
    -570
    -577
    -576
    -569
    -573
    -570
    -570
    -572
    -577
    -575
    -577
    -576
    -574
    -575
    -576
    -569
    -577
    -570
    -575
    -577
    -565
    -576
    -575
    -567
    -568
    -571
    -575
    -567
    -574
    -574
    -579
    -568
    -569
    -574
    -571
    -579
    -571
    -574
    -568
    -574
    -571
    -576
    -575
    -574
    -570
    -574
    -574
    -575
    -572
    -578
    -575
    -577
    -575
    -576
    -574
    -577
    -574
    -572
    -573
    -570
    -575
    -573
    -572
    -571
    -570
    -561
    -577
    -564
    -575
    -570
    -575
    -578
    -573
    -577
    -567
    -572
    -574
    -568
    -573
    -574
    -575
    -568
    -576
    -573
    -570
    -573
    -575
    -581
    -568
    -575
    -574
    -572
    -578
    -567
    -575
    -581
    -577
    -581
    -570
    -577
    -573
    -579
    -579
    -571
    -575
    -570
    -578
    -568
    -577
    -575
    -582
    -575
    -566
    -571
    -568
    -578
    -568
    -570
    -568
    -578
    -571
    -573
    -575
    -578
    -576
    -571
    -581
    -569
    -573
    -573
    -574
    -575
    -568
    -585
    -576
    -577
    -569
    -573
    -572
    -571
    -581
    -572
    -577
    -568
    -579
    -575
    -567
    -573
    -576
    -576
    -568
    -571
    -569
    -571
    -572
    -580
    -578
    -575
    -569
    -577
    -572
    -572
    -573
    -574
    -572
    -573
    -571
    -577
    -563
    -573
    -573
    -570
    -574
    -573
    -569
    -566
    -580
    -571
    -572
    -572
    -571
    -573
    -578
    -571
    -570
    -571
    -572
    -572
    -569
    -572
    -576
    -579
    -562
    -578
    -563
    -574
    -573
    -573
    -572
    -576
    -576
    -574
    -577
    -572
    -578
    -574
    -577
    -577
    -574
    -576
    -581
    -569
    -573
    -569
    -567
    -572
    -576
    -571
    -574
    -569
    -572
    -572
    -571
    -576
    -575
    -573
    -568
    -577
    -572
    -583
    -574
    -571
    -574
    -570
    -579
    -577
    -576
    -572
    -573
    -570
    -570
    -575
    -573
    -576
    -579
    -573
    -573
    -574
    -576
    -578
    -572
    -582
    -569
    -571
    -575
    -576
    -573
    -569
    -568
    -572
    -568
    -573
    -571
    -571
    -575
    -574
    -573
    -564
    -578
    -573
    -570
    -574
    -573
    -576
    -566
    -573
    -574
    -577
    -578
    -570
    -575
    -569
    -576
    -573
    -577
    -576
    -575
    -572
    -578
    -571
    -578
    -573
    -563
    -577
    -572
    -578
    -570
    -576
    -568
    -582
    -574
    -571
    -576
    -573
    -569
    -572
    -568
    -569
    -574
    -570
    -575
    -566
    -567
    -570
    -569
    -572
    -575
    -573
    -571
    -578
    -571
    -580
    -567
    -579
    -568
    -580
    -569
    -577
    -578
    -570
    -577
    -571
    -581
    -576
    -577
    -580
    -570
    -571
    -575
    -573
    -572
    -579
    -571
    -572
    -574
    -577
    -565
    -572
    -575
    -571
    -577
    -573
    -571
    -572
    -574
    -574
    -573
    -575
    -572
    -575
    -578
    -578
    -569
    -573
    -572
    -570
    -577
    -579
    -576
    -572
    -568
    -569
    -569
    -570
    -569
    -579
    -573
    -568
    -570
    -579
    -571
    -567
    -579
    -578
    -576
    -579
    -571
    -576
    -571
    -574
    -572
    -577
    -577
    -574
    -574
    -573
    -575
    -567
    -574
    -573
    -577
    -570
    -570
    -577
    -576
    -570
    -572
    -578
    -571
    -579
    -570
    -578
    -567
    -578
    -572
    -573
    -570
    -576
    -576
    -571
    -574
    -563
    -571
    -570
    -571
    -577
    -567
    -574
    -574
    -569
    -577
    -567
    -573
    -570
    -575
    -574
    -578
    -577
    -567
    -572
    -572
    -573
    -571
    -574
    -568
    -572
    -569
    -568
    -574
    -579
    -560
    -581
    -577
    -578
    -574
    -567
    -572
    -575
    -570
    -578
    -579
    -577
    -571
    -577
    -568
    -579
    -576
    -576
    -575
    -574
    -573
    -567
    -573
    -572
    -570
    -576
    -574
    -578
    -576
    -581
    -571
    -571
    -576
    -569
    -576
    -570
    -573
    -573
    -574
    -575
    -574
    -578
    -565
    -573
    -574
    -575
    -570
    -571
    -571
    -575
    -565
    -581
    -574
    -576
    -572
    -578
    -575
    -568
    -572
    -569
    -574
    -574
    -580
    -575
    -573
    -574
    -575
    -571
    -581
    -573
    -575
    -575
    -569
    -580
    -571
    -571
    -576
    -576
    -571
    -564
    -577
    -569
    -573
    -574
    -580
    -567
    -579
    -574
    -569
    -574
    -573
    -572
    -571
    -578
    -567
    -582
    -567
    -572
    -569
    -575
    -571
    -571
    -572
    -578
    -573
    -575
    -571
    -569
    -574
    -573
    -577
    -572
    -580
    -579
    -574
    -570
    -580
    -573
    -575
    -573
    -579
    -569
    -566
    -574
    -573
    -575
    -576
    -578
    -574
    -579
    -573
    -575
    -567
    -574
    -571
    -579
    -571
    -575
    -578
    -567
    -579
    -572
    -572
    -573
    -576
    -579
    -576
    -570
    -577
    -569
    -578
    -571
    -574
    -577
    -580
    -582
    -571
    -579
    -570
    -574
    -575
    -577
    -579
    -575
    -578
    -573
    -576
    -572
    -576
    -576
    -573
    -572
    -570
    -573
    -571
    -572
    -570
    -574
    -577
    -572
    -575
    -567
    -577
    -565
    -574
    -576
    -575
    -578
    -574
    -572
    -571
    -571
    -578
    -570
    -576
    -580
    -570
    -572
    -571
    -576
    -574
    -572
    -569
    -573
    -578
    -575
    -579
    -570
    -574
    -578
    -573
    -573
    -577
    -573
    -577
    -574
    -574
    -566
    -574
    -575
    -576
    -573
    -572
    -575
    -571
    -571
    -575
    -576
    -578
    -583
    -577
    -582
    -576
    -581
    -573
    -571
    -577
    -578
    -581
    -576
    -576
    -574
    -570
    -571
    -573
    -575
    -574
    -574
    -567
    -573
    -577
    -572
    -577
    -573
    -578
    -574
    -573
    -572
    -574
    -576
    -569
    -578
    -577
    -581
    -572
    -579
    -569
    -570
    -568
    -574
    -569
    -577
    -574
    -569
    -577
    -571
    -572
    -578
    -577
    -575
    -579
    -572
    -574
    -567
    -574
    -571
    -575
    -570
    -578
    -569
    -578
    -569
    -568
    -573
    -573
    -584
    -578
    -578
    -578
    -577
    -569
    -573
    -568
    -571
    -567
    -576
    -577
    -574
    -569
    -570
    -574
    -569
    -575
    -575
    -578
    -569
    -572
    -571
    -568
    -572
    -576
    -577
    -572
    -573
    -575
    -575
    -575
    -565
    -572
    -573
    -576
    -574
    -572
    -571
    -567
    -574
    -570
    -573
    -570
    -580
    -579
    -578
    -572
    -577
    -570
    -577
    -574
    -578
    -571
    -577
    -578
    -569
    -576
    -569
    -581
    -574
    -577
    -574
    -580
    -571
    -572
    -569
    -570
    -579
    -577
    -575
    -576
    -569
    -573
    -576
    -572
    -577
    -576
    -581
    -577
    -577
    -577
    -574
    -575
    -581
    -577
    -578
    -576
    -578
    -571
    -582
    -573
    -577
    -575
    -571
    -583
    -574
    -575
    -571
    -573
    -570
    -567
    -574
    -575
    -571
    -574
    -573
    -571
    -582
    -567
    -579
    -574
    -572
    -577
    -577
    -576
    -571
    -574
    -570
    -574
    -576
    -579
    -578
    -574
    -571
    -574
    -573
    -576
    -577
    -576
    -575
    -569
    -572
    -574
    -574
    -576
    -580
    -579
    -575
    -574
    -575
    -570
    -576
    -575
    -575
    -572
    -572
    -573
    -574
    -571
    -572
    -573
    -570
    -577
    -576
    -575
    -571
    -571
    -570
    -575
    -577
    -573
    -567
    -566
    -577
    -571
    -573
    -573
    -581
    -574
    -572
    -574
    -574
    -578
    -572
    -570
    -576
    -572
    -584
    -574
    -573
    -574
    -574
    -573
    -574
    -575
    -572
    -574
    -573
    -582
    -569
    -573
    -571
    -571
    -565
    -577
    -579
    -573
    -576
    -568
    -572
    -566
    -577
    -574
    -574
    -571
    -570
    -572
    -576
    -576
    -573
    -577
    -569
    -575
    -570
    -571
    -579
    -572
    -578
    -566
    -575
    -573
    -575
    -572
    -571
    -568
    -574
    -574
    -578
    -574
    -581
    -571
    -567
    -572
    -573
    -575
    -575
    -578
    -574
    -575
    -567
    -573
    -571
    -568
    -579
    -576
    -575
    -571
    -575
    -574
    -570
    -577
    -570
    -573
    -578
    -575
    -570
    -572
    -571
    -567
    -568
    -576
    -572
    -578
    -572
    -573
    -571
    -569
    -572
    -576
    -571
    -575
    -573
    -569
    -574
    -568
    -575
    -577
    -579
    -578
    -574
    -576
    -574
    -573
    -574
    -570
    -578
    -575
    -575
    -581
    -576
    -574
    -572
    -575
    -572
    -581
    -571
    -573
    -567
    -570
    -576
    -570
    -578
    -575
    -578
    -580
    -568
    -575
    -571
    -572
    -568
    -574
    -571
    -571
    -579
    -561
    -569
    -568
    -573
    -574
    -572
    -580
    -573
    -575
    -567
    -565
    -570
    -580
    -570
    -570
    -577
    -573
    -569
    -569
    -573
    -570
    -576
    -570
    -574
    -577
    -571
    -575
    -565
    -574
    -565
    -576
    -575
    -565
    -568
    -570
    -572
    -572
    -564
    -574
    -576
    -572
    -573
    -575
    -579
    -576
    -572
    -578
    -575
    -573
    -578
    -565
    -569
    -570
    -569
    -568
    -576
    -580
    -574
    -576
    -580
    -573
    -575
    -567
    -586
    -576
    -580
    -573
    -577
    -578
    -580
    -574
    -569
    -571
    -574
    -574
    -571
    -570
    -564
    -571
    -574
    -580
    -576
    -575
    -577
    -576
    -571
    -574
    -576
    -575
    -573
    -576
    -574
    -577
    -572
    -572
    -578
    -566
    -580
    -574
    -574
    -574
    -569
    -575
    -569
    -572
    -569
    -580
    -571
    -570
    -574
    -568
    -567
    -570
    -571
    -576
    -574
    -572
    -576
    -572
    -573
    -573
    -569
    -576
    -574
    -576
    -570
    -573
    -571
    -577
    -574
    -566
    -578
    -574
    -574
    -570
    -573
    -567
    -572
    -569
    -579
    -572
    -578
    -576
    -566
    -572
    -568
    -566
    -564
    -572
    -567
    -576
    -572
    -565
    -566
    -574
    -575
    -573
    -578
    -573
    -576
    -568
    -572
    -570
    -572
    -574
    -578
    -569
    -569
    -567
    -566
    -573
    -566
    -573
    -575
    -577
    -574
    -567
    -575
    -568
    -569
    -567
    -571
    -573
    -571
    -575
    -565
    -573
    -567
    -577
    -570
    -578
    -573
    -574
    -570
    -570
    -567
    -575
    -574
    -571
    -575
    -569
    -575
    -577
    -574
    -571
    -570
    -574
    -571
    -576
    -578
    -574
    -566
    -571
    -575
    -565
    -576
    -573
    -575
    -570
    -582
    -566
    -575
    -573
    -575
    -574
    -577
    -571
    -577
    -574
    -573
    -572
    -568
    -577
    -582
    -574
    -575
    -579
    -576
    -566
    -573
    -565
    -563
    -576
    -571
    -572
    -576
    -563
    -570
    -577
    -568
    -571
    -579
    -569
    -575
    -567
    -574
    -572
    -571
    -573
    -567
    -570
    -567
    -573
    -569
    -575
    -573
    -580
    -576
    -580
    -569
    -572
    -571
    -573
    -580
    -580
    -574
    -578
    -575
    -574
    -570
    -571
    -573
    -575
    -577
    -570
    -569
    -571
    -576
    -573
    -577
    -572
    -573
    -578
    -579
    -570
    -575
    -571
    -576
    -571
    -573
    -571
    -575
    -570
    -574
    -575
    -572
    -567
    -576
    -568
    -573
    -572
    -574
    -564
    -574
    -569
    -564
    -580
    -578
    -574
    -579
    -567
    -569
    -575
    -576
    -578
    -573
    -570
    -569
    -576
    -569
    -578
    -575
    -574
    -579
    -576
    -574
    -574
    -565
    -568
    -565
    -574
    -578
    -571
    -569
    -574
    -573
    -568
    -572
    -574
    -572
    -579
    -571
    -571
    -573
    -577
    -577
    -575
    -575
    -575
    -571
    -573
    -570
    -576
    -568
    -574
    -574
    -574
    -574
    -569
    -574
    -569
    -567
    -577
    -576
    -573
    -582
    -571
    -582
    -572
    -575
    -571
    -574
    -572
    -584
    -576
    -574
    -571
    -581
    -572
    -573
    -582
    -573
    -579
    -575
    -577
    -572
    -577
    -574
    -579
    -570
    -573
    -570
    -573
    -571
    -574
    -567
    -581
    -577
    -579
    -573
    -576
    -572
    -569
    -572
    -573
    -576
    -570
    -577
    -572
    -579
    -570
    -577
    -566
    -572
    -567
    -577
    -575
    -576
    -576
    -574
    -566
    -571
    -566
    -574
    -574
    -579
    -577
    -580
    -574
    -575
    -569
    -572
    -574
    -570
    -576
    -576
    -579
    -577
    -573
    -580
    -574
    -579
    -571
    -573
    -571
    -568
    -566
    -575
    -570
    -582
    -574
    -564
    -570
    -568
    -569
    -570
    -570
    -578
    -572
    -579
    -564
    -578
    -567
    -579
    -576
    -572
    -578
    -572
    -581
    -565
    -579
    -571
    -574
    -575
    -581
    -578
    -567
    -573
    -570
    -578
    -571
    -575
    -572
    -581
    -574
    -575
    -574
    -574
    -573
    -582
    -574
    -578
    -582
    -575
    -573
    -570
    -572
    -574
    -578
    -572
    -574
    -580
    -574
    -580
    -569
    -569
    -574
    -573
    -570
    -574
    -577
    -573
    -576
    -576
    -571
    -574
    -574
    -571
    -569
    -573
    -586
    -570
    -573
    -577
    -576
    -577
    -581
    -580
    -573
    -576
    -574
    -573
    -577
    -570
    -580
    -575
    -569
    -571
    -576
    -573
    -580
    -568
    -578
    -573
    -573
    -574
    -569
    -573
    -574
    -569
    -575
    -571
    -566
    -568
    -565
    -575
    -572
    -569
    -568
    -576
    -580
    -577
    -576
    -570
    -576
    -576
    -575
    -579
    -576
    -579
    -576
    -576
    -571
    -566
    -568
    -569
    -574
    -573
    -570
    -571
    -578
    -571
    -572
    -573
    -578
    -571
    -578
    -568
    -574
    -572
    -575
    -567
    -575
    -572
    -576
    -568
    -569
    -571
    -571
    -579
    -568
    -570
    -579
    -568
    -569
    -574
    -577
    -575
    -573
    -576
    -573
    -572
    -566
    -569
    -575
    -581
    -576
    -577
    -570
    -571
    -576
    -575
    -571
    -578
    -571
    -574
    -570
    -586
    -575
    -573
    -568
    -571
    -577
    -580
    -576
    -574
    -572
    -572
    -573
    -575
    -570
    -583
    -577
    -580
    -582
    -575
    -569
    -573
    -575
    -574
    -567
    -575
    -577
    -575
    -570
    -570
    -575
    -573
    -573
    -577
    -570
    -582
    -565
    -579
    -570
    -571
    -573
    -565
    -576
    -577
    -580
    -575
    -571
    -572
    -579
    -572
    -574
    -575
    -575
    -575
    -571
    -574
    -567
    -575
    -579
    -577
    -568
    -572
    -572
    -566
    -572
    -569
    -575
    -573
    -569
    -577
    -567
    -578
    -568
    -581
    -572
    -575
    -574
    -569
    -577
    -574
    -572
    -574
    -573
    -575
    -579
    -567
    -576
    -572
    -573
    -573
    -575
    -572
    -573
    -572
    -572
    -573
    -573
    -575
    -577
    -573
    -577
    -574
    -571
    -577
    -572
    -572
    -564
    -576
    -572
    -574
    -570
    -572
    -568
    -573
    -571
    -568
    -574
    -578
    -580
    -572
    -578
    -572
    -573
    -572
    -568
    -577
    -573
    -577
    -577
    -574
    -570
    -575
    -573
    -579
    -578
    -574
    -578
    -568
    -573
    -567
    -575
    -572
    

  • Hi,

    Is there any update for our above query regarding the ADC integrated noise improvement at terminated condition?

    Regards,
    Sugumar K
  • Hi Sugumar

    I did some quick analysis of your data file and see that the noise floor is around -76 dBFS instead of the -78dBFS level I see with the ADC16DV160HFEB evaluation board.

    So it seems like your platform has some source of additional noise. Can you try locating the source of noise by doing the following:

    • Try using external 1.8V and 3.0V supplies for the ADC
    • Try using an external clock signal generator for the clock source
    • If the first two steps don't yield any results, then try changing the input network capacitor values (equivalent to C21, C22, C7, C13, C52, C53 in the ADC16DV160HFEB design)

    Best regards,

    Jim B

  • Hi Jim

    We are generate the ADC sampling clock from LMK4808B PLL device. The sampling clock details are below

    Sampling clock Frequency : 160Mhz

    Clock Electrical Standard : 2000mVp-p LVPECL

    Refer the attached image for measured clock at 220 ohm termination resistor is placed in b/w clock ouptut signal and Gnd with ac coupling capacitors in both(+ve and -ve) of lines LVPECL output. Will any modification in the termination circuitry used has impact in improving SNR?.

    or Whether can try with LVDS clock output for SNR improvement?

    Kindly advise.

  • Hi Auxilian

    You are already using the LMK04808 output mode setting that provides the highest slew rate and swing, which should optimize ADC SNR.

    The only other suggestion I have is to try a lower value LVPECL termination resistors (120 ohm instead of 220 ohm) to see if that provide any change in SNR. The lower termination value will give a slight increase in slew rate over the one you are currently using.

    Increasing the ADC clock slew rate and thereby lowering the possibility for clock jitter should help with SNR performance with high frequency large amplitude input signals. Reduced jitter won't make a significant difference in the baseline noise floor when no input signal is applied. In that condition other factors must be considered, like power supply noise, and other digital noise getting into the ADC circuitry.

    Best regards,

    Jim B

  • Hi,

    Kindly refer the below link and reply as soon as possible.

    e2e.ti.com/.../598273

    Regards
    James A
  • Hi James
    I have responded to that thread.
    Jim B