AAT1235 Analogic Corporation, AAT1235 Datasheet - Page 2

• Manufacturer Part Number: AAT1235
• Manufacturer: Analogic Corporation

Pin Descriptions
Pin Configuration
2
Pin #
10, 11
EP
12
13
14
15
16
1
2
3
4
5
6
7
8
9
Symbol
EN/SET
AGND
RSET
GND
VIN
N/C
SW
LIN
OV
B1
B2
A3
A2
A1
IN
Function
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 cur-
rent 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 floating.
2
Cwire control or enable pin.
EN/SET
RSET
GND
VIN
OV
B1
B2
IN
1
2
3
4
5
6
7
8
TDFN34-16
(Top View)
High Efficiency White LED Drivers
16
15
14
13
12
10
11
9
LIN
A1
A2
A3
AGND
N/C
N/C
SW
for Backlight and Keypad
1235.2007.01.1.0