AAT1235IRN-T1 AnalogicTech, AAT1235IRN-T1 Datasheet - Page 2

• Manufacturer Part Number: AAT1235IRN-T1
• Description: High Efficiency White LED Drivers for Backlight and Keypad
• Manufacturer: AnalogicTech

Pin Descriptions
Pin Configuration
2
SwitchReg
Pin #
10, 11
12
13
14
15
16
EP
1
2
3
4
5
6
7
8
9
Symbol Function
EN/SET
AGND
RSET
GND
VIN
N/C
SW
LIN
OV
B1
B2
IN
A3
A2
A1
TM
Input supply for the converter. Connect a 2.2μF or larger ceramic capacitor from VIN to GND.
Boost output over voltage detect pin. Use resistor divider to set the circuit’s external over-voltage protection.
See Applications Information for details.
AS
Backlight current sink 1. Connect the cathode of the last LED in the string to B1.
Backlight current sink 2. Connect the cathode of the last LED in the string to B2.
LED current set resistor. A 22.6kΩ resistor from RSET to AGND sets the maximum LED current in A1-A3 and
B1-B2 to 20mA.
Input bias supply for the internal circuitry. Connect IN to VIN directly at the AAT1235.
Ground for the boost converter. Connect GND to AGND at a single point as close to the AAT1235 as practical.
Boost converter switching node. A 2.2μH inductor, connected between SW and LIN, sets the boost converter's
switching frequency.
Not connected.
Ground pin. Connect AGND to GND at a single point as close to the AAT1235 as practical.
Auxiliary current sink 3. Connect the cathode of the last LED in the string to A3.
Auxiliary current sink 2. Connect the cathode of the last LED in the string to A2.
Auxiliary current sink 1. Connect the cathode of the last LED in the string to A1.
Switched power input. Connect LIN to the external power inductor.
Exposed paddle (bottom) Connected internally to SW. Connect to SW or leave fl oating.
2
Cwire control or enable pin.
High Efficiency White LED Drivers for Backlight and Keypad
EN/SET
RSET
GND
w w w . a n a l o g i c t e c h . c o m
VIN
OV
B1
B2
IN
1
2
3
4
5
6
7
8
TDFN34-16
(Top View)
10
16
15
14
13
12
11
9
LIN
A1
A2
A3
AGND
N/C
N/C
SW
PRODUCT DATASHEET
AAT1235
1235.2009.09.1.2