AAT1138 Datasheet, PDF (2/21 Pages) Skyworks Solutions Inc. – 2A Step-Down Converter with Adjustable Input Current Limit

Pin Descriptions
Pin #
1, 6, 15
2, 3
4, 5
7
8
9
10, 11
12
13
14
16
Symbol
GND
SW
PGND
SYSIN
ENSYS
SET
SYSOUT
ENBUCK
PVIN
SVIN
FB
EP
DATA SHEET
AAT1138
2A Step-Down Converter with Adjustable Input Current Limit
Function
Analog ground pin.
Switching node pin. Connect the output inductor to this pin.
Power ground pin for the step-down converter.
System input power. P-channel MOSFET source. Connect a 1μF capacitor from SYSIN to GND.
Enable input for system power load switch. Active Low.
Input current limit set input. A resistor from SET to ground sets the current limit for the input
load switch.
System output power. P-channel MOSFET drain.
Enable input for step-down converter. Active high. Connect to PVIN when enabling the step-
down converter. Do not leave ENBUCK floating.
Power supply input pin for step-down converter. Must be closely decoupled to PGND with a 22μF
or greater ceramic capacitor.
Analog supply input pin. Provides bias for internal circuitry. Connect to PVIN.
Feedback pin for step-down converter. Connect FB to the center point of the external resistor
divider. The feedback threshold voltage is 0.6V.
Exposed pad. Must be connected to bare copper ground plane.
Pin Configuration
TDFN34-16
(Top View)
GND ¹
SW ²
SW ³
PGND ⁴
PGND ⁵
GND ⁶
SYSIN ⁷
ENSYS ⁸
16 _FB
15 _GND
14 _SVIN
EP
13 _PVIN
12 _ENBUCK
11 SYSOUT
10 _SYSOUT
9 _SET
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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201978B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • March 15, 2013