Voltage Regulators
1
AN8041S
Liquid crystal backlight control IC
n Overview
The AN8041S is an inverter control IC for liquid
crystal backlight using PWM method. The output
voltage of DC-DC converter and the current of cath-
ode-ray tube can be controlled by using two error
amplifiers, so that the system is designed easily.
Since the n-channel MOSFET can be directly
driven, it is possible to construct a highly effective
power supply.
n Features
• Operating supply voltage: 3.6 V to 34 V
*
• Totem pole output circuit: Output current of – 500 mA
• Built-in bootstrap circuit
• N-channel power MOSFET can be directly driven
• Built-in two error amplifier circuits allow both the
voltage and current control
• Incorporating on/off functions (active-high control input, standby mode current is 5 m A or less)
• Built-in timer latch short-circuit protection circuit
• Maximum oscillation frequency: 500 kHz
Note)
*
: The voltage is limited to the range of 3.6 V to 17 V if used in a step-down circuit.
n Applications
• LCD displays, digital still cameras, and PDAs
n Block Diagram
SOP016-P-0225A
Unit: mm
0.3
(0 to 10 )
(0.15)
Seating plane
10.1±0.3
4.2±0.3 6.5±0.3
18
16 9
1.27
(0.605)
Seating plane
0.40±0.25
0.1±0.1
1.5±0.2
CB
14
Out
13
FB1
8
IN+1
6
IN- 1
7
S.C.P.
5
Off
16
DTC
4
V
REF
1
GND
12
S.C.P.
comp.
Q
Q
R
S
V
CC
15
Bootstrap
CT
3
Constant
current source
RT
2
OSC
V
REF
2.57 V
On/off
active-high
PWM comp.
Error amp. 2
U.V.L.O.
Q
R
S
Latch
Error amp. 1
FB2
9
IN+2
11
IN- 2
10