Liteon Semiconductor Corporation
LSP3122A
300KHZ 5A PWM Buck DC/DC Converter
Rev1.1
1/11
PIN CONFIGURATION
(1) TO220-5L
(2) TO263-5L
(Top View)
Symbol
Name
Descriptions
1
Vin
Operating Voltage Input
2
Output
Switching Output
3
Gnd
Ground
4
FB
Output Voltage Feedback Control
5
SD
ON/OFF Shutdown
FEATURES
Output voltage: 3.3V, 5.0V, 12V, and adjustable
output version
Adjustable version output voltage range:1.23V to
37V±3%
300KHz±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 40V
Output load current: 5A
Low power standby mode
Built-in switching transistor on chip
TO220-5L,TO263-5L packages
APPLICATIONS
Simple High-efficiency step-down regulator
On-card switching regulators
Positive to negative converter
GENERAL DESCRIPTION
The LSP3122A series are monolithic IC that design
for a step-down DC/DC converter, and own the
ability of driving a 5A 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. The
LSP3122A series operates at a switching frequency
of 300 KHz thus allowing smaller sized filter
components than what would be needed with lower
frequency switching regulators. Other features
include a guaranteed ±3% 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 , and a 5-lead
TO-263 package.
Metal Tab Gnd
1 VIN
2 OUTPUT
3 GND
4 FB
5 SD
1
2
3
4
5
VIN
OUTPUT
GND
FB
SD
Metal Tab Gnd