hi dear supporting team,
in customer's p/l, they recently found several failure cases on SN74CB3Q3257. they use PIN5,PIN6 and PIN7 for bi-directional I2C data write and read.
the phenomenon is the for failed chip:PIN7 output get to only 1.2Vpp , which should originally be 3.3Vpp. and the impedance of PIN6&PIN7 change from Mohm to Kohm.
when we measure the brd input&output signal, we only get abnormal signal with max -1V negative overshoot @PIN7. as below plot, but this plot is gotten with long soldered cable , if detect directly on brd, we could only get max -0.54V negative overshoot. understand that the absolute rating is only -0.5V, but for such very short pulse, will it also burn the chip? tks a lot!
