Power Management
MICROELECTRONICS
A
A
GM34063
1.5A DC-TO-DC CONVERTER CONTROL CIRCUIT
Description
GM34063 has all the functions required for DC-to-DC
converters: an internal temperature- compensated ref-
erence, comparator, controlled duty cycle oscillator
with an active current limit circuit, driver, and high-
current output switch.
GM34063 is designed for step-down, step-up and volt-
age-inverting applications by using a minimum number
of external components.
Features
3.0V to 40V input
Adjustable Output Voltage
Current Limiting
Output Switch Current to 1.5A
Low Standby Current
Operating Frequency to 100kHz
Precision 2% Reference
Application
CD-ROM
Motherboards
SMPS Power Supply
Battery Chargers
DSL Modem
SCHEMATIC DIAGRAM
8
Driver Collector
S
R
7
I
pk
Sense
I
pk
Oscillator
C
T
6
V
CC
100
Q
Q2
Q1
1
Switch Collector
2
Switch Emitter
3
Comparator
+
-
1.25V
Reference
Regulator
Timing Capacitor
5
Comparator
Inverting Input
(Bottom View)
4
GND
www.gammamicro.com
GM34063
1
V0.1
GAMMA [ GAMMA MICROELECTRONICS INC. ]
