SN74LVCH16245A: Abnormal output issue with SN74LVCH16245A

Hi Team,

My customer is using SN74LVCH16245A and met problem, below is simplified block diagram to showing you the issue:

For the condition,

1. A port is input and B port is output;

2. OE is pulled high, disabled;

3. Vcc=3.3V;

Issue: with above condition, when measure the B port, we got about 1.25V voltage here and also measured about 0.25mA leakage current.

Questions:

1. Because OE is pulled high to make the output high impedance, so the problem is how the leakage current come from? What is the "high impedance" really mean for SN74LVCH16245A? For customer, high impedance means really high impedance with very low leakage current(Maybe nA or even pA). Need expert help clarify on this.

2. BTW, I see SN74LVCH16245A support bus-hold function, and this can't be disable by DIR or OE pin. So does above leakage current caused by this bus-hold circuit? If so, 0.25mA leakage current and 1.25V voltage means that the pull down resistor is about 500 ohm, is this true(A more detailed internal circuit will be very helpful to understand this)? Pls correct me if this is mis-understanding.

3. If SN74LVCH16245A do have this leakage current, which can't be used here, do we have recommendation for customer?

Thanks a lot for your support!

Best regards,

Sulyn