Unidentified switching regulator from Netgear LB2120

[octillion]

I inadvertently reversed the input voltage on a Netgear LB2120 LTE modem, killing the switching regulator.  I've been unsuccessful identifying a replacement.  The 8-pin part has "IAQAH" laser etched on top.  I'm not sure exactly what SMD package it is, the package itself is about 2.8 x 1.4 mm with a lead spacing of about 0.65 mm, no exposed pad on the bottom.  See attached image for removed crispy part next to the power circuitry (laser etching was much more legible before desoldering).

The desired output seems to be 5 volts, as I manually injected power to the modem to get it functioning.  An LED lit at 3.3 volts, but it was otherwise non-operational; 5 volts works.


Pinout is as follows:

Pin 1) 22 nF capacitor to GND (C88)

Pin 2) V_in (supplied with 12 V 1 Amp SMPS wall adapter)

Pin 3) OUT (to 3.3 uH inductor; I find no external diode, so likely internal)

Pin 4) GND


Pin 5) RC back to pin 3 (20 Ohm R82, 0.1 uF C91)

Pin 6) Enable (100 kOhm pull-up to V_in, external latching push-button shorts this to GND for "off" state)

Pin 7) 0.1 uF capacitor to GND (C90)

Pin Feedback.  R77 (5.6 kOhm) to R80 and R78/C89.  R80 (10 kOhm) to GND.  R78 (>=13.8 kOhm) to R76 (10 Ohm).  R76 to via which somehow finds it's way to the output voltage.


Thanks for any help here.

[PA0PBZ]

MP2235SGJ

[octillion]

We've got a winner, thanks PA0PBZ!