i've designed in an TXB0108DQSR in a tiny pcb toghether with a Flash SPI n.v.m.; this small pcb patches a bigger board were a Master working at 1.8V was driving an older 1.8V Flash nvm, enabling the use of a newer 3V3 part.
The traslator's VDDA and OE pins are tied to a 1.8V rail, whereas VCCB is powered from a 3V3 rail. Both powers are accurate in voltage and clean.
I can see clock, mosi, chip_select .. regularly swinging 0-1.8V on traslator A side pins, (1V8, used as inputs), but nothing more than low level garbage glitches about 0 Vdc on corresponding output pins at side B.
Have already checked all of wirings and tried replacing the TXB0108 chip, without success.
The SPI clock has >100nS period, and about 50% D.C. so minimum pulse width from TXB0108 datasheet is respected.
Here's the patch schematic.
I really can't understand what's wrong, can anyone explain it and/or share any solution/idea?
thanx
Francesco
