Hi,
I have made one voltage translating test setup on GP Board, consisting of 3 level translators (2 nos. of TXB0108PWR and 1 no. of SN74LVC8245) and connectors to interface between Micro controller (3.3V logic) and FPGA (2.5V logic) for testing.
While testing:
Case 1:
It is observed that for input of 3.3V, 5MHz Square wave signal at two I/O pins of TXB0108PWR, outputs come with glitch before every rising edge of the output signals(2.5V, 5MHz) if we probe simultaneously on corresponding output pins using CRO probe(10X mode).
Case 2:
If we probe on single output pin at a time, output becomes glitch free.
But, another translator SN74LVC8T245 (unidirectional) doesn’t give glitch at output for the same input signal for both the above cases.
I have taken care to make all the necessary connection for translator(TXB0108PWR).
1. VCCA is 2.5V
2. VCCB is 3.3V
3. OE pin connected to VCCB
Please anybody suggest what could be the problem. I have very short time in my hand as this setup is going to use in a design.
