The LM2575 /LM2575HV series operates at a switching
frequency of 52 kHz thus allowing smaller sized filter compontents
than what would be needed with lower frequency
switching regulators. Available in a standard 5-lead TO-220
package with several different lead bend options, and a
5-lesd TO-262 surface mount package.
The LM2575 /LM2575HV series of regulators are monolithic
integrated circuits that provide all the active functions for a
step-down (buck) switching regulator, capable of driving a 2A
load with excellent line and load regulation. These devices
are available in fixed output voltages of 3.3V, 5V, 12V, and an
adjustable output version.
General Description
Requiring a minimum number of external components, these
regulators are simple to use and include internal frequency
compensation†, and a fixed-frequency oscillator.
A standard series of inductors are available from
several different manufacturers optimized for use with the
LM2575series. This feature greatly simplifies the
design of switch-mode power supplies.
Other features include a guaranteed ±4% tolerance on output
voltage under specified input voltage and output
load conditions, and ±15% on the oscillator frequency.
External shutdown is included, featuring typically 80 μA
standby cur-rent. Self protection features include a two
stage frequency reducing current limit for the output
switch and an over temperature shutdown for complete
protection under fault conditions.
Available in TO-220 and TO-263,TO-220B packages
(57V for HV version)
Features
n 3.3V, 5V, 12V, and adjustable output versions
n Adjustable version output voltage range, 1.2V to 37V
±4% max over line and load conditions
n
n Guaranteed 2A output load current
n Input voltage range up to 40V
n Requires only 4 external components
n Excellent line and load regulation specifications
n 52 kHz fixed frequency internal oscillator
n TTL shutdown capability
n Low power standby mode, IQ typically 80 μA
n High efficiency
n Uses readily available standard inductors
n Thermal shutdown and current limit protection
Applications
n Simple high-efficiency step-down (buck) regulator
n On-card switching regulators
n Positive to negative converter
Note: †Patent Number 5,382,918.