1.5 A, Step−Up/Down/
Inverting Switching
Regulators
The
STC
34063 Series is a monolithic control circuit containing the
primary functions required for DC−to−DC converters. These devices
consist of an internal temperature compensated reference, comparator,
controlled duty cycle oscillator with an active current limit circuit,
driver and high current output switch. This series was specifically
designed to be incorporated in Step−Down and Step−Up and
Voltage−Inverting applications with a minimum number of external
components.
PDIP−8
8
1
SO−8
8
1
PIN CONNECTIONS
Switch
Collector
Switch
Emitter
Timing
Capacitor
GN
D
Driver
Collector
I
pk
Sense
V
CC
Comparator
Inverting
Input
•
•
•
•
•
•
•
Operation from
2.5
V to
30
V Input
Low Standby Current
Current Limiting
Output Switch Current to 1.5 A
Output Voltage Adjustable
from 1.25 to 30V
Frequency Operation
from 100Hz
to 100 kHz
Precision
1%Reference
1
2
3
4
8
7
6
5
(Top View)
Drive 8
Collector
S Q
I
pk
7
Sense
R
100
I
pk
Oscillator C
T
6
V
CC
Comparator
+
−
Comparator 5
Inverting
Input
(Bottom View)
1.25 V
Reference
Regulator
Q2
Q1
1
Switch
Collector
2
Switch
Emitter
3
Timing
Capacitor
4
GN
D
This device contains 51 active transistors.
Figure 1. Representative Schematic Diagram
1
S34063
SUNTAC [ SUNTAC ELECTRONIC CORP. ]
