Document
Liteon Semiconductor Corporation LSP3120
52KHZ 3A PWM Buck DC/DC Converter
FEATURES
Output voltage: 3.3V, 5.0V, 12V, and adjustable output version Adjustable version output voltage range:1.23V to 37V±4% 52KHz±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: 3A Low power standby mode Built-in switching transistor on chip TO220-5L,TO263-5L packages
GENERAL DESCRIPTION
The LSP3120 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. The LSP3120 series operates at a switching frequency of 52 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 5-lead TO-263 package. (2) TO263-5L
APPLICATIONS
Simple High-efficiency step-down regulator On-card switching regulators Positive to negative converter
PIN CONFIGURATION
(1) TO220-5L (Top View) (Top View)
5 SD FB GND OUTPUT VIN
5 SD 4 FB 3 GND 2 OUTPUT 1 VIN
4 3 2 1
Metal Tab Gnd
Metal Tab Gnd
Symbol 1 2 3 4 5
Name Vin Output Gnd FB SD Operating Voltage Input Switching Output Ground Output Voltage Feedback Control ON/OFF Shutdown
Descriptions
1/9
Rev1.0
Free Datasheet http://www.datasheet4u.com/
Liteon Semiconductor Corporation LSP3120
52KHZ 3A PWM Buck DC/DC Converter
BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Symbol VCC VSD VFB VOUT PD TST TOP VOP Paramrter Supply Voltage ON/OFF Pin input Voltage Feedback Pin Voltage Output Voltage to Ground Power Dissipation Storage Temperature Operating Temperature Operating Voltage Rating +45 -0.3 to +25 -0.3 to +25 -1 Internally Limited -65 to +150 -40 to +125 +4.5 to +40 V Unit V V V V W
2/9
Rev1.0
Free Datasheet http://www.datasheet4u.com/
Liteon Semiconductor Corporation LSP3120
52KHZ 3A PWM Buck DC/DC Converter
ELECTRICAL CHARACTERISTICS (ALL OUTPUT VOLTAGE VERSIONS)
Unless otherwise specified, VIN=12V for 3.3V,5V, adjustable version and VIN=24V for the 12V version. ILOAD=0.5A Symbol Paramrter Conditions Min. Typ. Max. Unit VFB=1.3V(Adjustable 50 40 nA IB Feedback bias current version on.