question form the Field:
Customer uses 2 X TXB0104 for I2S signal level shift. One is from 3.3V->1.8V and one is for 1.8V->3.3V. Both has issues below.
I use the 3.3V->1.8V as example. The 3.3V is codec voltage and the 1.8V is the MTK platform for tablet.
I2S has MCLK and other signal. The problem is from the >250k signal. Like MCLK. Other lower speed signal will not have this issue, like LRCLK.
If the load is not connected. The output of MCLK didn’t have obvious problem. But when the load is installed(on the board, a 0ohm resistor is installed), the output of TXB0104 will have issue. The signal is not pulled down and has oscillation at logic low. And the input signal will be affected from the output, too. But when there is no load, the input and output signal will not have issues.
So could you please kindly suggest how to debug it?
I checked the schematics and find there is no other pull up or pull down resistors on the signal traces. The trace is long, too, Just in a tablet scale.
Please help solve the issue
