TSW1400 and AFE7225

Lucifer

Expert 2600 points

Other Parts Discussed in Thread: AFE7225, CDCE72010, AFE7222

Dear Sir,

I have encountered a problem for the connection between TSW1400 and AFE7225.

The TSW1400 didn’t receive a valid clock from AFE7225, the ADC/DAC function is not work.

Do you know how to solve it? thanks.

p.s. our test procedure is from TI website, but can’t see clock output from AFE7225

U2(CDCE72010) got a 100MHz external clock(AUXCLK) from J10

After the config of TI tool(AFE722x EVM software control ver1.3)

U2.pin7 should output a clock for U1(AFE7222/AFE7225)

But I can’t see it.

If U1 didn’t receive this clock, the whole ADC/DAC process will not run.

http://www.ti.com/lit/ug/slou362/slou362.pdf

http://www.ti.com/lit/ug/slwu087c/slwu087c.pdf

over 9 years ago

0 KW Nam over 9 years ago

TI__Expert 8895 points

Hello,

TSW1400 requires an external clock at 3/4 of the AFE7225 clock rate. The external clock (J10) needs to be x3 of AFE7225 sampling clock. Assuming your configuration is x4 of interpolation, please refer to the clock diagram shown as below. For the full rate of DAC (245.76MHz), you'll have to provide 737.28MHz of external clock with J10 on AFE722xEVM.

Thanks,

0 Lucifer over 9 years ago in reply to KW Nam

Expert 2600 points

Dear Sir,

But I can’t see any clock output from CDCE72010.

When I input a 100MHz into CDCE72010 (J10/CDC AUXCLK).

And I’m expected it could output 100MHz/3=33.33MHz into AFE7225, but I see nothing.???? Thanks.

0 KW Nam over 9 years ago in reply to Lucifer

TI__Expert 8895 points

Hello,

From the configuration of CDCE72010, the divider of output0 is '3' and "16" for output2 when x4 interpolation from AFE722xEVM GUI. If you leave your email address, I'd send you a quick slide for setup.

Thanks,

0 Lucifer over 9 years ago in reply to KW Nam

Expert 2600 points

Dear KW,
this is my E-mail address below, Thanks.
shinnyi@ymail.com

0 Lucifer over 9 years ago in reply to Lucifer

Expert 2600 points

Dear Sir,

I got new problem and need your help!!

I would like to record a signal -> save to csv -> edit to arbitrary file -> output this file by function generator(AFG-2225)

For ADC record, I have following step:

1. Function generator output a 40k/1Vpp sine wave into TI ADC7225+TSW1400 board

2. save the result to csv file

It will have 65535 data row

3. get the first 4096 row of csv file,

And edit to arbitrary file.

4. Function generator read the arbitrary file, and output to spectrum

5. I can’t see a 40k single tone in spectrum.

Do you know how to fix this problem? Thanks.

ADC7225+TSW1400 board

0 jim s over 9 years ago in reply to Lucifer

TI__Guru* 91947 points

What is your ADC sample rate? You may not be looking at enough data points. Try using the full 65K samples. If you cannot do this, try sampling a much higher IF or use a ramp test pattern and see if you can see this using 4096 samples. How does the results look when you capture it with HSDC Pro?

Regards,

Jim

0 Lucifer over 9 years ago in reply to jim s

Expert 2600 points

Dear Sir,

Regarding to the AFE7222 EVM

Can we get the dBm instead of dBFs??

Below is our capture result, could we get a capture in dBm unit? Thanks.

0 KW Nam over 9 years ago in reply to Lucifer

TI__Expert 8895 points

dBm is not available from HSDC Pro tool.

Thanks,
KW

0 Lucifer over 9 years ago in reply to KW Nam

Expert 2600 points

Dear Sir,

Is any way that I can we mapping the dBFs level to dBm level? Thansk.

0 KW Nam over 9 years ago in reply to Lucifer

TI__Expert 8895 points

dBm is a absolute value while dBFS is a relative one. It is difficult to translate it to dBm without gain budget on the system.

Thanks,

0 Lucifer over 9 years ago in reply to KW Nam

Expert 2600 points

Dear Sir,

We have some questions need your help:
1. What’s the gain value while we perform ADC?
2. If we have gain, what’s the gain type
(1) fix gain
(2) various gain, setting internal
(3) various gain, setting manually in the GUI

Thanks.

0 KW Nam over 9 years ago in reply to Lucifer

TI__Expert 8895 points

Hello,

AFE7225 has capabilities to adjust gain during operation. Analog gain can be selected from mixer stage, which are -2.5dB, -6dB and 0dB to prevent saturation of incoming signal. Another analog gain stage is located in DAC. They are fine/coarse control, which fine stage ranges 0.04*full_scale ~ -0.04* full_scale while coarse one has 16 steps of full scale of ADC.

The QMC (Quadrature Modulation Correction) gain is digitally controlled, and this is for gain compensation for I/Q gain mismatching to minimize sideband image.

Thanks,

0 Lucifer over 9 years ago in reply to KW Nam

Expert 2600 points

Dear Sir,

An other question for RX Mixer Gain setting of AFE7225 GUI, if we un-click the box , will the gain be fixed or auto? Thanks.

0 KW Nam over 9 years ago in reply to Lucifer

TI__Expert 8895 points

Hello,

The gain will be fixed, not auto.

Thanks,

0 Lucifer over 9 years ago in reply to KW Nam

Expert 2600 points

Dear KW,

thanks for your kindly reply.

may I know the fixed gain would be? 0, -2.5, -6

Thanks.

0 KW Nam over 9 years ago in reply to Lucifer

TI__Expert 8895 points

Hello,

You can select RX mixer gain from register, which are 0, -2.5 or -6dB. This is to avoid saturation of received signal from mixer output.

Thanks,
KW

0 Lucifer over 9 years ago in reply to KW Nam

Expert 2600 points

Dear KW,
as you previously mentioned the gain will be fixed if we un-click the box RX Mixer Gain, what the gain value at this situation is ? Thanks.

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TSW1400 and AFE7225