Question
Why do the ADuM3190 and ADuM4190 have two error amplifier outputs?
Answer
The ADuM3190/ADuM4190 have an EAOUT pin 6 which has an output voltage specified
to 2.4V and an EAOUT2 pin 7 which is specified to 5.0V. The EAOUT2 pin provides
a higher voltage to help drive the COMP pin of a PWM controller which may
require 5V. The internal circuits of the ADuM3190/ADuM4190 run off internal
3.0V regulators, which is why the EAOUT pin 6 is limited to less than 3V. The
EAOUT2 pin has an open drain circuit which is used with an external pull-up to
connect to a VDD supply voltage of 3V to 20V, which is how EAOUT2 can be rated
to 5.0V.