150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3123
FEATURES
Output voltage: 3.3V, 5.0V, 12V, and adjustable
output version
Adjustable version output voltage range:1.23V to
18V±4%
150KHz±15% fixed switching frequency
Voltage mode non-synchronous PWM control
Thermal-shutdown and current-limit protection
ON/OFF shutdown control input
Operating voltage can be up to 22V
Output load current: 3A
Low power standby mode
Built-in switching transistor on chip
TO220-5L，TO263-5L and PDIP8L packages
GENERAL DESCRIPTION
The FSP3123 series are monolithic IC that design for
a step-down DC/DC converter, and own the ability of
driving a 3A load without additional transistor
component. Due to reducing the number of external
component, the board space can be saved easily.
The external shutdown function can be controlled by
logic level and then come into standby mode. The
internal compensation makes feedback control have
good line and load regulation without external design.
Regarding protected function, thermal shutdown is to
prevent over temperature operating from damage,
and current limit is against over current operating of
the output switch. If current limit function occurred and
V
FB
is down to 0.5V below, the switching frequency
will be reduced. The FSP3123 series operates at a
switching frequency of 150 KHz thus allowing smaller
sized filter components than what would be needed
with lower frequency switching regulators. Other
features include a guaranteed ±4% tolerance on
output voltage under specified input voltage and
output load conditions, and ±15% on the oscillator
frequency. The output version included fixed 3.3V,
5V, 12V, and an adjustable type. The packages are
available in a standard 5-lead TO-220 package, a
5-lead TO-263 package or 8-lead PDIP.
APPLICATIONS
Simple High-efficiency step-down regulator
On-card switching regulators
Positive to negative converter
PIN CONFIGURATION
(1) TO220-5L
(Top View)
5 SD
4 FB
3 GND
2 OUTPUT
1 VIN
(2) TO263-5L
(Top View)
5
4
3
2
1
SD
FB
GND
OUTPUT
VIN
Metal Tab Gnd
Metal Tab Gnd
(3) PDIP8L
(Top View)
GND GND
8
7
GND
6
GND
5
1
2
3
4
SD
VIN OUTPUT FB
Symbol
TO220/TO263
PDIP
1
1
2
2
3
5~8
4
3
5
4
Name
Vin
Output
Gnd
FB
SD
Descriptions
Operating Voltage Input
Switching Output
Ground
Output Voltage Feedback Control
ON/OFF Shutdown
1/11
2007-6-12
FOSLINK [ FOSLINK SEMICONDUCTOR CO.,LTD ]
