TXS0108E: I am not getting 1PPS which is of 5V/3.3V when passed through TXS0108E

neeraj gururaj bidarahalli

Part Number: TXS0108E
Other Parts Discussed in Thread: TXU0101

I am using ZCU111 Xilinx RF board and I am passing 1PPS though a PMOD connector, which in-turn is connected to TXS0108E.

I am not able to get Proper 1PPS to my FPGA. I am seeing scrambled PPS.

over 2 years ago

0 Clemens Ladisch over 2 years ago

Guru 299090 points

The TXS does not work well with high capacitive or inductive loads, such as long traces, cables, or connectors.

For unidirectional signals, you should use a unidirection translator like the TXU0101.

0 neeraj gururaj bidarahalli over 2 years ago in reply to Clemens Ladisch

Prodigy 30 points

Hi Clemens: To rule out long traces/cables/connector issue. I tried to Loopback, internally generated PPS given one PMOD-0 connector and connected to PMOD-1 as input.

PPS generated internally has 50% duty cycle.

I am observing

I am Observing active low signal at PMOD1_1 which is looped back output from PMOD0_1[internally generated PPS].

I was expecting PPS which i sent out with 50% duty cycle should be received at PMOD1_1. But its not coming like that.

0 Clemens Ladisch over 2 years ago in reply to neeraj gururaj bidarahalli

Guru 299090 points

What is the waveform at the 3.3 V signal?

Can you show an oscilloscope trace instead?

0 neeraj gururaj bidarahalli over 2 years ago in reply to Clemens Ladisch

Prodigy 30 points

My issue got resolved as there was an issue with IO standard in FPGA. PMOD0_0_LS had POD12 in XDC file given by xilinx. When changed to LVCMOS12 we are getting 1PPS properly

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TXS0108E: I am not getting 1PPS which is of 5V/3.3V when passed through TXS0108E