DATA SHEET
AAT2822/2823/2824/2825
TFT-LCD DC/DC Converter with WLED Driver and VCOM Buffer
Pin Descriptions
Pinout is preliminary and subject to change during development.
Pin Number
AAT2822
AAT2823
AAT2824
1
AAT2825
1
Symbol
WLX
PGND2
REF
FBN
WEN
DRVN
VDD
DRVP
EN
FBP
PGND1
LX
COMP
FB
OPIN
OP+
OP-
OUT
WCOMP
WFB
OVP
VIN
AGND
WDIM
N/C
GND
Function
O
I/O
O
I
I
O
PI
O
I
I
I/O
O
I
O
I
I
I
O
I
O
O
I
I/O
I
Description
Boost inductor node. Connect an inductor between IN and WLX.
WLX is high impedance in shutdown.
Power ground. Connect to GND underneath the IC.
Internal reference bypass terminal. Connect a 0.1µF capaci-
tor from this terminal to analog ground (GND). External load
capability to 50µA.
Negative charge-pump regulator feedback input. Regulates to
0V nominal.
Active high logic level enable for WLED Driver.
Negative charge-pump driver output. Output high level is VDD,
and low level is PGND.
Positive and negative charge-pump driver supply voltage. By-
pass to PGND with a 0.1µF capacitor.
Positive charge-pump driver output. Output high level is VINP,
and low level is PGND.
Active high logic level enable input. Connect EN to IN for normal
operation.
Positive charge-pump regulator feedback input. Regulates to
0.6V nominal. Connect feedback resistive divider to analog
ground (GND).
Power ground. Connect to GND underneath the IC.
Main boost regulator power MOSFET N-channel drain. Connect
output diode and output capacitor as close to PGND as possible.
Step-up regulator error-amplifier compensation point. Connect
a series RC from COMP to AGND.
Main boost regulator feedback input. Regulates to 0.6V nomi-
nal. Connect feedback resistive divider to analog ground (GND)
to set output voltage.
Operational-amplifier power input. Power supply rail for the
operational amplifiers. Typically connected to VAVDD. Bypass
OPIN to GND with a 0.1µF capacitor.
Operational-amplifier non-inverting input.
Operational-amplifier inverting input.
Operational-amplifier output.
White LED driver error-amplifier compensation point. Connect a
series RC from WCOMP to AGND.
Feedback pin. Connect a resistor to ground to set the maximum
LED current.
Feedback pin for over-voltage protection sense. Connect a re-
sistive divider between the boost converter output and ground.
Supply input. +2.5V to +5.5V input range. Bypass with a 0.1µF
capacitor between IN and GND, as close to the pins as possible.
Analog ground. Connect to power ground (PGND) underneath
the IC.
Dimming control input. Apply a PWM signal up to 1kHz to adjust
the WLED brightness from 100% to 5%, proportional to the
duty cycle of the PWM signal.
Not connected.
Ground. EP = Exposed paddle, connect to PCB ground plane.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
n/a
EP
1
2
3
4
5
6
7
8
9
10
11
12
13
14
n/a
n/a
n/a
n/a
19
20
21
22
23
24
15, 16,
17, 18
EP
n/a
2
3
4
n/a
6
7
8
9
10
11
12
13
14
15
16
17
18
n/a
n/a
n/a
22
AGND
n/a
1, 19, 20,
21
5, 24, EP
n/a
2
3
4
n/a
6
7
8
9
10
11
12
13
14
n/a
n/a
n/a
n/a
n/a
n/a
n/a
22
AGND
n/a
1, 15, 16, 17,
18, 19, 20, 21
5, 24, EP
1. Future products. Please contact factory for availability.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com
202081B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 2, 2012
3
AAT [ ADVANCED ANALOG TECHNOLOGY, INC. ]
