Diodes AP3421/A/B - Manual (Page 3)

Preliminary Datasheet
1.3MHz, Dual 1.0A Synchronous Step-down Converters AP3421/A/B
Feb. 2013 Rev. 1. 4 BCD Semiconductor Manufacturing Limited
3
Pin Description (Continued)
Pin Number Pin Name Function
8 POR
Power on reset output pin. Monitors FB1, FB2 output
voltage levels and V
IN
. POR is pulled low if an output
voltage drop is detected on FB1 or FB2 or VIN, and is
Hi-Z during normal operation
9 VMON
Voltage monitor–supervisor for one external voltage
(could be input voltage). The POR output is triggered if
this output falls below the VMON threshold
10 FB1
Feedback from VO1. Connect voltage divider to the
load side of VO1 output inductor-capacitor filter
11 AGND
Signal ground connection. Provide a star connection
between this pin and PGND pin