In our 1K machines, there is a strange phenomenon in 12pcs.
The impedance of all its PIN to GND is normal, INA:0.45V,INB:0,37V,OUTA:0V,OUTB:0.6V (because it is directly connected to the base of the transistor, so this value can be considered high).
Obviously, the logic of the OUTA output is wrong at this time.
After my further verification, I found that no matter what the input voltage is, OUTA always outputs low,OUTB and always outputs high. It looks as if its internal reference source has become very large.
I can assure you that the input voltage has entered the IC because I measured it on its PIN.
I can also make sure that OUT's pull high is connected.
And these abnormal IC are problems that only appear to the customer after they have been fully tested.
