DC/DC Converter

PF754-03

DESCRIPTION

The SCI7654 is a highly efficient, but low power-consumption DC-to-DC converter based on the advanced CMOS

technologies. It can generate an output voltage double/triple/quadruple times higher than the input (in negative

direction) if 4/3/2 external capacitors are attached.

With a built-in voltage regulator, the SCI7654 can provide a stable output by setting the DC/DC output to any voltage

via two external resistors. This is optimum to the LCD panel power supply as the stable output can have the negative

temperature gradient required for an LCD panel.

FEATURES

An input voltage can be boosted double/triple/quadruple to negative potential.

Input voltages: –2.4 to –5.5V (quadruple boosting), –2.4 to –7.3V (triple boosting), –2.4 to –11.0V (double

boosting)

Excellent vol tage conversion efficiency: 95% (Typ.)

Large output current: 20 mA (Max.) during quadruple boosting

Built-in voltage regulator (for stable voltage output)

Built-in reference voltage source for accurate regulation: –1.5

±0.05V (CT0)

Regulator output voltage temperature gradient function: –0.04, –0.15, –0.35, –0.55%/˚C

Low current consumption: 130

µA (Typ.)

Low standby current: 5.0

µA (Max.)

Built-in oscillator circuit

5/6-time voltage boosting in negative potential by serial connection

BLOCK DIAGRAM

Double/Triple/Quadruple Boosting

95% Excellent Power Conversion Efficiency

Built-in Voltage Regulator

POFF1

POFF2

FC

C1P

C2P

C1N

C3N

C2N

TC1

TC2

RV

Power-Off

Control

Clock

Generator

Voltage Converter

Booster Control

Ref. Voltage

Circuit

Voltage Regulator