PRODUCT DATASHEET
AAT1184
TM
SwitchReg
High Voltage Step-Down Regulator
Pin Descriptions
Pin #
Symbol
Function
Output current sense pin. Connect a small signal resistor from this pin to switching node (LX) to en-
able over-current sense for step-down converter.
Enable input pin. Active high.
1
2
RS
EN
Boost drive input pin. Connect the cathode of fast rectifier from this pin and connect a 100nF ca-
pacitor from this pin to the switching node (LX) for internal hi-side MOSFET gate drive.
Step-down converter switching pin. Connect output inductor to this pin. Connect LX pins together.
Input supply voltage pin for step-down regulator. Connect both IN pins together. Connect the input
capacitor close to this pin for best noise performance.
3
BST
LX
4, 5
6, 7
8
IN
VL
Internal linear regulator. Connect a 2.2μF/6.3V capacitor from this pin to GND pin.
Ground pin for step-down converter. Connect input and output capacitors return terminals close to
this pin for best noise performance.
9
GND
Feedback input pin for step-down converter. Connect an external resistor divider to this pin to pro-
gram the output voltage to the desired value.
Compensation pin for step-down regulator. Connect a series resistor, capacitor network to compen-
sate the voltage mode control loop.
Output voltage sense pin. Connect to the output capacitor to enable over-current sense for step-
down converter.
10
11
12
FB
COMP
OS
Pin Configuration
TSOPJW-12
(Top View)
1
2
3
4
5
6
12
11
10
9
RS
EN
BST
LX
OS
COMP
FB
GND
VL
IN
8
LX
7
IN
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1184.2008.07.1.0
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