Internal

Regulator

ON/OFF

_

+

_

+

1.23-V

Band-Gap

Reference

52-kHz

Oscillator

Reset

Thermal

Shutdown

Current

Limit

FEEDBACK

7

CIN

+

VIN

6

Unregulated

DC Input

GND

5, 12, 13

OUTPUT

3

ON/OFF

9

COUT

+

D1

L

O

A

D

VOUT

1-A

Switch

Driver

Fixed-Gain

Error Amp

Comparator

R2

R1

R1 = Open, R2 = 0

Ω

L1

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Folder

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LM2575

SLVS569F – JANUARY 2005 – REVISED AUGUST 2015

LM2575 1-A Simple Step-Down Switching Voltage Regulator

1 Features

3 Description

The LM2575 device greatly simplifies the design of

1

•

Adjustable With a Range of 1.23 V to 37 V and

switching power supplies by conveniently providing all

±4% Regulation (Max) Over Line, Load, and

the active functions needed for a step-down (buck)

Temperature Conditions

switching regulator in an integrated circuit. Accepting

•

Specified 1-A Output Current

a wide input voltage range and available in an

adjustable output version, the LM2575 has an

•

Wide Input Voltage Range 4.75 V to 40 V

integrated switch capable of delivering 1 A of load

•

Uses Readily Available Standard Inductors

current, with excellent line and load regulation. The

•

52-kHz (Typical) Fixed-Frequency Internal

device also offers internal frequency compensation, a

Oscillator

fixed-frequency

oscillator,

cycle-by-cycle

current

•

TTL Shutdown Capability With 50-

μA (Typical)

limiting, and thermal shutdown. In addition, a manual

shutdown is available through an external ON/OFF

Standby Current

pin.

•

High Efficiency…as High as 88% (Typical)

The LM2575 represents a superior alternative to

•

Thermal Shutdown and Current-Limit Protection

popular three-terminal linear regulators. Due to its

With Cycle-by-Cycle Current Limiting

high efficiency, it significantly reduces the size of the

•

For the Full Offering of Voltages (Including Fixed-

heat sink and, in many cases, no heat sink is

Output Options) and Packages (Including TO-

required. Optimized for use with standard series of

263), See TL2575 Data Sheet, SLVS638

inductors

available

from

several

different

manufacturers, the LM2575 greatly simplifies the

2 Applications

design of switch-mode power supplies by requiring a

minimal

addition

of

only

four

to

six

external

•

Simple High-Efficiency Step-Down (Buck)

components for operation.

Regulator

The LM2575 is characterized for operation over the

•

Pre-Regulator for Linear Regulators

virtual junction temperature range of –40°C to 125°C.

•

On-Card Switching Regulators

•

Positive-to-Negative Converter (Buck-Boost)

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

LM2575N

PDIP (16)

19.30 mm × 6.35 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Simplified Schematic

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.