AAT2847_08 Datasheet, PDF (2/20 Pages) Advanced Analogic Technologies – Four-Channel Backlight Driver with Dual LDOs

ChargePump^TM
PRODUCT DATASHEET
AAT2847
Four-Channel Backlight Driver with Dual LDOs
Pin Descriptions
Pin #
1
2
3
4, 6
5
7
8
9
10
11
12
13
14
15
16
17
18
19
20
EP
Symbol
AAT2847-EE AAT2847-QG/QI
D2
D2
D1
LDOB
IN
PGND
FBA
LDOA
C2-
C2+
OUT
C1-
C1+
EN/SET
ENB
D4
D1
LDOB
IN
PGND
NC
LDOA
C2-
C2+
OUT
C1-
C1+
EN/SET
ENB
D4
D3
GND
ENA
FBB
D3
GND
ENA
N/C
Function
LED2 current channel input. Connect to the cathode of backlight LED 2. If not
used, connect D2 to the OUT pin.
LED1 current channel input. Connect to the cathode of backlight LED 1. If not
used, connect D1 to the OUT pin.
Output of LDOB.
Input voltage supply connection.
Power Ground.
AAT2847-EE: Feedback pin of LDOA. Internally regulated at 1.2V.
AAT2847-QG/QI: No connection. Do not make any connection to this pin.
Output of LDOA.
Negative terminal of flying capacitor 2.
Positive terminal of flying capacitor 2.
Charge pump output to drive load circuit. Connect a 1µF or larger ceramic ca-
pacitor between OUT and PGND.
Negative terminal of flying capacitor 1.
Positive terminal of flying capacitor 1.
AS²Cwire control pin for backlight LED current profile selection and control.
Enable pin for LDOB. Active logic high.
LED4 current channel input. Connect to the cathode of backlight LED 4. If not
used, connect D4 to the OUT pin.
LED3 current channel input. Connect to the cathode of backlight LED 3. If not
used, connect D3 to the OUT pin.
Ground.
Enable pin for LDOA. Active logic high.
AAT2847-EE: Feedback pin of LDOB. Internally regulated at 1.2V.
AAT2847-QG/QI: No connection. Do not make any connection to this pin.
Exposed pad (bottom).
Pin Configuration
AAT2847-EE
TQFN34-20
(Top View)
AAT2847-QG/QI
TQFN34-20
(Top View)
D2 ¹
D1 ²
LDOB ³
IN ⁴
PGND ⁵
IN ⁶
16 _D4
15 _ENB
14 _EN/SET
13 _C1+
12 _C1-
11 _OUT
D2 ¹
D1 ²
LDOB ³
IN ⁴
PGND ⁵
IN ⁶
16 _D4
15 _ENB
14 _EN/SET
13 _C1+
12 _C1-
11 _OUT
2
www.analogictech.com
2847.2008.05.1.2