A7121A
DC-DC CONVERTER BUCK (STEP-DOWN)
1MHz, 2.0A, SYNCHRONOUS
AiT Semiconductor Inc.
www.ait-ic.com
PIN DESCRIPTION
Top View
Symbol
Top View
Pin #
SOT-25
Function
SOT-26
1
Regulator Enable control input. Drive EN above
1.1V to turn on the part. Drive EN below 0.6V to turn it off. In
shutdown, all functions are disabled drawing <1μA supply current. Do
not leave EN floating.
1
EN
2
3
2
3
GND
LX
Ground
Power Switch Output. It is the Switch note connection to inductor.
This pin connects to the drains of the internal P-CH and N-CH
MOSFET switches.
Power supply input pin. Must be closely decoupled to GND with a
22μF or greater ceramic capacitor.
Power Good Indicator. This pin is an open drain logic output.
Connect PG to an external pull-up resistor and get a high level
output. PG is pulled to ground when the output voltage is less than
91.5% of the target output voltage.
Let PG float or connect to ground when don’t use PG function.
Feedback Input Pin. Connect FB to the center point of the external
resistor divider. The feedback threshold voltage is 0.6V.
4
-
4
5
6
VIN
PG
FB
5
REV1.3
- JUL 2013 RELEASED, NOV 2016 UPDATED -
- 2 -
AITSEMI [ AiT Semiconductor ]
