Voltage Level Translation Forum - Recent Threads

F28335 Voltage Level Shifter

Luis Coimbra — Tue, 21 May 2013 16:01:18 GMT

Hi, my name is Pedro

I'm doing a project for my university. I'm using the F28335 to send pulses to a voltage source inverter.

I need a voltage level shifter from the 3.3 V output of the dsp to the 15 V CMOS (inverter), preferably with more than 6 bits.

Can anyone point me to a reference or a solution?

Thank You

TXS02612 / transition duration time from B0 to B1

Ryuji Asaka — Mon, 20 May 2013 16:14:53 GMT

Hello,

Could you please kindly let me know about TXS02612?

Could you please kindly let me know the transition duration time(max) from B0 to B1 of DAT/CLK/CMD by "SEL pin from L to H"?

I can see the tpd from SEL to B-Port in the SWITCHING CHARACTERISTICS.(red circle of attached image)

Is this data my expecting data?

Best Regards,

Ryuji Asaka

CD4504B datasheet question

Stan Sassower — Tue, 14 May 2013 01:55:21 GMT

Start of the CD4504B datasheet says: TTL to CMOS, the SELECT input is at Vcc. When the SELECT input is LOW, CMOS to CMOS. This seems to be contradicted by the legends under figs 9 and 10 of 2004 datasheet, (8,9 of 2008 datasheet). Which is correct?

TXS0108E

srimannarayana masimukku — Wed, 27 Feb 2013 09:03:29 GMT

Hi,

I want to use TXS0108E for my applications. in my application i want to convert the voltage levels from 5V or 3.3V to 1.8V or 2.5V. For the I2C , SPI and UART should I use the TXS0108E .can any body please suggest me for right selection.

SN74AVCA164245 as Data Converter / SPI Level Translator

Brian Vincent Arellano — Wed, 15 May 2013 10:09:38 GMT

Hello Everyone...

I have a data converters (16-bit 80MSPS, AD9269BCPZ-80 and 16-bit 160MSPS, AD9777BSVZ both data converters are from analog devices) with interfaces running at 3.3V and want to connect it to an FPGA Bank configured to 1.8V VCCIO. I'm using SN74AVCA164245 as a level translator between the data converters and FPGA.

Does anyone have experience interfacing SN74AVCA164245 with data converters with similar sampling rate and any problems encountered? Can anyone recommend a better suited level translator for this application?

Also I have an SPI interface (25MHz) that needs to be level shifted, can I use SN74AVCA164245 for this SPI Interface?

Thanks, Brian

TXS0108E POWER CONSUMPTION

Alberto Alcay del Pozo — Mon, 13 May 2013 13:46:14 GMT

Hello

I want to use TX0108E devide to translation the 1.8V AM3715 JTAG signal to 3.3V.

In the data sheet it is specify that the maximum continuous current through VCCA, VCCB and GND is 100 mA. On the other hand in the same table it is specify that the maximum continuous output current is 50 mA (I undertand that this value is per pin, am I right?).

Can`t the continuos output current be higher than 100 mA?

Can I used this devide for the application listed aboved?

Best Regards,

Alberto

TXB0108 rise and fall time

Alberto Alcay del Pozo — Sun, 12 May 2013 09:18:01 GMT

Good morning,

I am designing a board and I need to convert the AM3715 JTAG signals to 3.3V for boundaring scan purpose. In order to guarantee a nice waveform I perform a signal integrity simulation.

In this simulation I found that the rise and fall time of the TXB0108 device are very very slow (about 50 ns or higher). I though that the problem was the capacitive load of the AM3715 device but I checked it and it has 2.2pF.

On the other hand I checked the TXB0108 data sheet and I found that the fall and rise time at 1.8V is 5.1ns maximum in port A.

Finally I performed the same simulation with TXS018E and the waveform was nice. So I assume that the TXB0108 IBIS model doesn`t work correctly. Am I right?

Could you please confirm this item? In case that the IBIS model doesn`t work correctly, could you please send me the IBIS model corrected?

Best Rregards,

Alberto

TXS0104 VIH port A at 1.8V

Martin Gustafsson — Wed, 08 May 2013 08:54:19 GMT

Hi!

I am looking into recomminding the TXS0104 for a 1.8V level conversion to 3.3V. Looking into the datasheet, the VIH for this communication into port A is specified as VCCI-0.2 min and VCCI max. When I drive this, I need to have a VOH on the same bus that is above this level. THis means that the VOH needs to be > VCCI, since this is max on VIH?

Can you please advice on how to read the data sheet?

Best regards, Martin

TXB0108 Problems converting

Meththa Samaranayake — Tue, 31 May 2011 11:07:27 GMT

I am using a TXB0108 data converter. This is used with a PIC32 chip which is working at 3.3V and an image sensor (Hamamatsu S10077) working at 5V. I use one of the lines to transfer a clock signal whilst all other connected pins are driven low. When I provide a clock signal (1MHz) from the PIC to the converter, to be sent through to the sensor, the output at the converter is 2.6V max (not 5V as expected). Furthermore there is a lot of ringing on the clock signal seen at the output of the converter. I would like the converter to provide an output of a 5V clock signal running at 1MHz.

The TXB0108, VccA is connected to 3.3V with a 100nF decoupling capacitor. VccB is connected to 5V with a 100nF decoupling capacitor. The OE signal is connected pulled high to 3.3V using a 10k ohm resistor. The input/output from the PIC32 is connected to port A and port B is used to connect to the sensor. Unused ports are connected directly to ground.

The image attached shows you the output at the PORT B IO pin where I am expecting the clock signal.

Am I connecting the translator correctly and can someone point me in the direction as to why this might be happening.

Thanks all.

SN74LVC1T45 Output

Michael Hershkovich — Sun, 05 May 2013 09:13:10 GMT

Hi,

I have a question regrading SN74LVC1T45 operation when there is no power input.

What is the output when VCCA and VCCB are both 0v ? Is the output 0v or floating?

Thanks,

Michael

Maximum frequency input to SN74AVC16T245

Dhaval Patel4 — Mon, 29 Apr 2013 05:40:10 GMT

I have ADS4229 Evaluation board. ADS4229 which has outputs are at 1.8V. I am using SN74AVC16T245 to convert +1.8V to 3.3V. Sampling rate of ADC is 245.76 MHz. Clock (sinewave)which is output from ADC (clockout) as input to SN74AVC16T245 to convert it to 3.3V.

When input clock frequency or sampling rate is less than 150 MHz it is working fine. When input clock frequency is 245.76 MHz, clockout from ADC is fine but output of SN74AVC16T245 is distorted.

So what is maximum frequency as input can be used with SN74AVC16T245 ?

What are other solutions I can used if SN74AVC16T245 not able to handle frequency higher that 150 MHz ?

Thanks.

TPL7200

Dave Weinzierl — Wed, 23 Jan 2013 03:30:59 GMT

Who's in charge of this part? When will samples be available? RTM?

It looks like a very interesting part for some of my sensor guys at John Deere.

Spice model files for chips (Eg. CD40109B)

Basavaraj Sankeshwar — Wed, 17 Apr 2013 12:17:51 GMT

Hello All,

I am new to the design field and I am using a Altium to design a circuit. However, my design consists of ICs like CD40109B (Level Shifter), few power MOSFETs etc. As I need to simulate the design in the software, I am not able to find the Spice model files from the TI site. There is just the footprint of the device available. Could any one please let me know how the spice model files can be obtained .

Thanks and Regards,

Basavaraj

74LVC1T45

Dick Berg — Fri, 05 Apr 2013 23:16:57 GMT

All - I'm looking for a drop-in replacement for the subject bus transceiver that has Schmitt trigger inputs.

Any suggestions would be appreciated.

Thanks,

Dick Berg

TXB0106 Translator problem

Jaison Joy — Wed, 03 Apr 2013 13:33:06 GMT

Hello,

I am interfacing an SPI communication between 5V(microcontroller) and 3.3V(audio IC) system.

Since I experienced loading effect at the 3.3V (VCCA) side, I added 4050 buffer and solved the problem as shown in the schematic.

But 3.3V data from A port is not getting translated to 5V at B port. It is showing ~2V at Pin11, ( related to Pin6, MISO_IN)

I am prototyping this TXB0106, so the data cable length are more than 10cms on both 5V and 3.3V systems. Will that cause any problem?

Please guide me to solve this problem.

12V interface to MSP430 using ULN2003

Shashank Revankar — Sun, 03 Feb 2013 13:23:14 GMT

Hello,

As mentioned in the application note - Input interface 3V & 5V circuit to MSP430 - (link here), I am trying to use ULN2003 to input interface a 12V circuit to MSP430.
I have tried the circuit as given in the doc.

Where should the "COM" terminal of MSP430 be connected? (not given in the doc)
I have tried these combinations

1) Connecting COM to 3.3V --> output of ULN at 3.3V at 12V input (no change if input is changed)
2) Connecting COM to GND --> output of ULN at 0.8V at 12V input (output 0 if input at 0V)
3) Not connecting COM --> output of ULN at 3.3V at 12V input (no change if input changed)

Has anyone successfully interfaced this way? If not, is there any low cost alternate way?

--Shashank

SN74AUP1G07 / for HPD of HDMI and CBUS of MHL

Ryuji Asaka — Wed, 13 Mar 2013 11:20:41 GMT

Hello,

Our customer would like to use one buffer IC for both signals of HPD and CBUS.

Then, I think that SN74AUP1G07 may be used as buffer IC of these signals by one device.

Can SN74AUP1G07 as buffer IC for HPD and CBUS signal?

Please see the attached file as our image.

(Please visit the site to view this file)

Best Regards,

Ryuji Asaka

Shifting and Scaling [0V / +15V] input to meet ADS1675REF requirements

mariano rotunno — Thu, 21 Mar 2013 14:12:20 GMT

Hi all,

i need to translate a (0,+15V) analog input to the range accepted by ADS1675REF board.

I've seen that the common mode voltage for this board is 2.5V and the ADS1675 input range is ±Vref so from datasheet i suppose is ±3V.

If i am right all this drives to an input that must lie inside a [2.5-3, 2.5+3] so finally i have to scale (0,+15) to (-0.5V, 5.5V) isn't it?

Any suggestion about circuit to realize this?

Thanks in advance

74LVC4245A & DIR signal

WILLIAM STEPHENS — Mon, 25 Mar 2013 21:05:17 GMT

Having problems with 74LVC4245A switching the DIR signal between a 3V & 5V bus. When the DIR signal is changed to drive from 3V side to 5V side a great deal of noise/ringing is seen on the 5V data bus.

The spec does not explicity say the DIR signal can be changed during operation - can it be?

Thanks for any help.

Bill

Multiple TXS0102E on same bus

Chip Slinger — Tue, 19 Mar 2013 15:30:29 GMT

We have a 1.8V processor I2C bus that needs to connect to 2.5V and 3.3V devices.

Can we put two TXS0102E devices on the processor bus, one to our 2.5V devices, and the other to our 3.3V devices?

Thanks.

TXS0108 and I2C

DJH — Wed, 16 Mar 2011 05:49:47 GMT

It seems fairly straightforward, but is there any reason why a TXS0108 wouldn't work with I2C? I've got a 2.8V part on one side and a 3.3V part on the other.

Thanks,

-David

Using TXS0104E

Steve Hardcastle — Tue, 24 Nov 2009 17:38:26 GMT

Hello

I would like to use the TXS0104E for an SPI bus application but the specification suggests that the input low voltage needs to be a maximum of 0.15 Volts. I don't know of any devices that guarantee to drive that low. The device I need to use has a VOL of 0.4 Volts.

Is there a special technique needed to satisfy the 0.15 volts?

TIA

Steve

Partial PowerDown Mode- Supply Current (IOFF)

Mahaboob Gadwal — Wed, 27 Feb 2013 12:21:07 GMT

Hi,

I'm writing testplan for Voltage Leve Translator(TXS0101). Finding diffuculty in writing Test Conditions for IOFF during Partial PowerDown Mode ( VCCA=active VCCB-0V). If I make VCCB=0V, will it make my outputs (either A or B) to go to high impedance state, or should I pull OE pin to GND through Rpd to make it. Is the IOFF is the Current on active Supply pin (VCCA) or is it current on Output pin (either A or B). Please clarify..

Thanks & Regards,

Baig.

TSX0108 Independent Channels

Chris Renick — Fri, 22 Feb 2013 00:40:33 GMT

Hi everyone,

This part is an 8-bit bidirectional level shifter with auto-direction sensing. I would like to know if each bit is independent of each other as far as direction goes. In other words, can any bit (channel) be in any direction. With other level shifters that use a Direction pin, the direction function applies to all the bits.

Thanks.

using SN74AVC8T245PWR to drive 165MHz clock

Suresh Palani — Sun, 24 Feb 2013 11:42:06 GMT

I have a HDMI transmitter in my design. I need to interface my HDMI transmitter Digital input side to my FPGA. My FPGA bank can be powered by only 1.5V. Hence i need level translator to convert into 3.3V for my HDMI transmitter digital input section. I am using SN74AVC8T245PWR as level translator. I have powered VCCA side with 1.5V and VCCB with 3.3V. As per the data sheet, the maximum data rate from A to B with this powering option is 170Mbps. I have level translated all data lines, HSYNC, VSYNC, FLD, DE through this buffer. My HDMI data is updated based on a clock signal of 165MHz.can i route 165MHz clock via this buffer comfortably. will i have any issues. please clarify.

Regards,

Ramesh.M