MAX1779 Datasheet, PDF (1/18 Pages) Maxim Integrated Products – Low-Power Triple-Output TFT LCD DC-DC Converter

19-1795; Rev 0; 11/00
Low-Power Triple-Output TFT LCD DC-DC
Converter
General Description
The MAX1779 triple-output DC-DC converter provides
highly efficient regulated voltages required by small
active matrix, thin-film transistor (TFT) liquid-crystal dis-
plays (LCDs). One high-power DC-DC converter and
two low-power charge pumps convert the +2.7V to
+5.5V input supply voltage into three independent out-
put voltages.
The primary high-power DC-DC converter generates a
boosted output voltage (V_MAIN) up to 13V that is regu-
lated within ±1%. The low-power BiCMOS control cir-
cuitry and the low on-resistance (1Ω) of the integrated
power MOSFET allows efficiency up to 91%. The
250kHz current-mode pulse-width modulation (PWM)
architecture provides fast transient response and
allows the use of ultra-small inductors and ceramic
capacitors.
The dual charge pumps independently regulate one
positive output (V_POS) and one negative output (V_NEG).
These low-power outputs use external diode and
capacitor stages (as many stages as required) to regu-
late output voltages up to +40V and down to -40V. A
proprietary regulation algorithm minimizes output rip-
ple, as well as capacitor sizes for both charge pumps.
The MAX1779 is available in the ultra-thin TSSOP pack-
age (1.1mm max height).
Features
o Three Integrated DC-DC Converters
o 250kHz Current-Mode PWM Boost Regulator
Up to +13V Main High-Power Output
±1% Accuracy
High Efficiency (91%)
o Dual Charge-Pump Outputs
Up to +40V Positive Charge-Pump Output
Down to -40V Negative Charge-Pump Output
o Internal Supply Sequencing
o Internal Power MOSFETs
o +2.7V to +5.5V Input Supply
o 0.1µA Shutdown Current
o 0.5mA Quiescent Current
o Internal Soft-Start
o Power-Ready Output
o Ultra-Small External Components
o Thin TSSOP Package (1.1mm max)
PART
MAX1779EUE
Ordering Information
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
16 TSSOP
________________________Applications
TFT Active-Matrix LCD Displays
Passive-Matrix LCD Displays
PDAs
Digital-Still Cameras
Camcorders
Typical Operating Circuit appears at end of data sheet.
Pin Configuration
TOP VIEW
RDY 1
FB 2
INTG 3
IN 4
GND 5
REF 6
FBP 7
FBN 8
MAX1779
TSSOP
16 TGND
15 LX
14 PGND
13 SUPP
12 DRVP
11 SUPN
10 DRVN
9 _SHDN
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