AIC1652
MICROPOWER INVERTING DC/DC CONVERTER
SPEC NO: DS-1652-02 DEC 27, 00
n FEATURES
n DESCRIPTION
The AIC1652 is a high performance inverting
DC/DC converter, designed to drive an external
power switch to generate programmable negative
voltages. In the particularly suitable LCD bias con-
trast application, efficiency of 87% can be
achieved with low cost PNP bipolar transistor driv-
ers. Output voltage can be scaled to -40V or
greater by two external resistors. A pulse frequen-
cy modulation scheme is employed to maintain
high efficiency conversion under wide input voltage
range. Quiescent current is about 80mA and can
be reduced to 0.7mA in shutdown mode. Switching
frequency being around 70KHz to 160KHz range,
small size switching components are ideal for bat-
tery powered portable equipments, like notebook
and palmtop computers.
l
l
l
l
2.4V to 7V Input Voltage Operation.
Adjustable Output Voltage up to -40V.
Low Quiescent Current at 80mA.
Pulse Frequency Modulation Maintains High
Efficiency (87%).
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70KHz to 160KHz Switching Frequency.
Power-Saving Shutdown Mode (0.7mA Typical).
High Efficiency with Low Cost External PNP
Bipolar Transistor.
n APPLICATIONS
l Negative LCD Contrast Bias for
1. Notebook & Palmtop Computers.
2. Pen-Based Data System.
3. Portable Data Collection Terminals.
4. Personal Digital Assistants.
l Negative Voltage Supply.
n TYPICAL APPLICATION CIRCUIT
VIN
2.4V ~ 7V
VIN
CL
DHI
m
100 F
+
Q1
9012
C1
VREF
AIC1652
RB
D1 1N5819
SHDN
FB
DLOW
470~1.8K
VOUT
-12V~ -40V
-10mA
GND
C2
m
150 H
*L
m
100 F
+
m
0.047 F
R2
R1
C3
*
Sumida CD-54 Series
VOUT = -1.22V x R1/R2
1M
C4
100K
10nF
Negative LCD Contrast Bias Power Supply
n ORDERING INFORMATION
AIC1652 XX
PIN CONFIGURATION
ORDER NUMBER
TOP VIEW
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
AIC1652CN
(PLASTIC DIP)
CL
VIN
1
2
3
4
8
7
6
5
DHI
VREF
DLOW
GND
SHDN
FB
TEMPERATURE RANGE
AIC1652CS
(PLASTIC SO)
°
°
C=0 C~+70 C
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
TEL: (8863)577-2500 FAX:(8863)577-2510
1
4F, 9 Industry E. 9th Road, Science-based IndustrialPark, Hsinchu, Taiwan, R.O.C.