LM1575/LM2575/LM2575HV Simple Switcher 1A Step Down Voltage Regulator LM2575SX-ADJ/NOPB

FEATURES                                                                                                               Connection Diagrams

                                                                                                              (XX indicates output voltage option.)

• 3.3V, 5V, 12V, 15V, and Adjustable Output

  Versions

• Adjustable Version Output Voltage Range,                                               

  – 1.23V to 37V (57V for HV Version) ±4%

     Max Over

  – Line and Load Conditions

• Specified 1A Output Current

• Wide Input Voltage Range, 40V up to 60V for

  HV Version

• Requires Only 4 External Components

• 52 kHz Fixed Frequency Internal Oscillator

• TTL Shutdown Capability, Low Power Standby

  Mode

• High Efficiency

• Uses Readily Available Standard Inductors                                           

• Thermal Shutdown and Current Limit

  Protection

• P + Product Enhancement Tested

APPLICATIONS

• Simple High-Efficiency Step-Down (Buck)

  Regulator

• Efficient Pre-Regulator for Linear Regulators                                            

• On-Card Switching Regulators

• Positive to Negative Converter (Buck-Boost)                                             

DESCRIPTION

The LM2575 series of regulators are monolithic

integrated circuits that provide all the active functions

for a step-down (buck) switching regulator, capable of

driving a 1A load with excellent line and load

regulation. These devices are available in fixed output

voltages of 3.3V, 5V, 12V, 15V, and an adjustable

output version.                                                                                             

Requiring a minimum number of external

components, these regulators are simple to use and

include internal frequency compensation and a fixed-

frequency oscillator.

The LM2575 series offers a high-efficiency

replacement for popular three-terminal linear

regulators. It substantially reduces the size of the

heat sink, and in many cases no heat sink is

required.

A standard series of inductors optimized for use with

the LM2575 are available from several different

manufacturers. This feature greatly simplifies the

design of switch-mode power supplies.

Other features include a specified ±4% tolerance on

output voltage within specified input voltages and

output load conditions, and ±10% on the oscillator

frequency. External shutdown is included, featuring

50 μA (typical) standby current. The output switch

includes cycle-by-cycle current limiting, as well as

thermal shutdown for full protection under fault

conditions.