Q
I have had a query from a customer they have wired an OP37 incorrectly.
Instead of +15V and 0V they have applied -6V on the V+ pin and +5V on the V-
pin, the parts were then powered up and the error realized. The problem was
corrected and the parts still seem to work. The question is what is likely to
have been damaged?
A
The OP37 contains no on-chip circuitry for protection against reversal of
supply voltage. If the OP37 has been exposed to a condition where V+ (pin7)
is more negative than V- (pin4) the OP37 has been permanently damaged. All
parts should replaced and discarded.
Damage due to supply reversal may occur as a catastrophic failure or may be
cumulative in nature and manifest as an early life failure. The fact that the
part “seem to work” should not be taken to mean that the parts have not been
damaged. Typical failure mechanisms included metal migration of connecting
tracks due to high currents, parasitic diodes and SCR mechanisms causing damage
to transistor base (partial punch through effect) and excess localized heating
upsetting transistor matching.