1

TC2575

TC2575-1 3/13/00

1.0A Step-Down Switching Regulator

1.0A Step-Down Switching Regulator

The TC2575 series of regulators are monolithic inte-

grated circuits ideally suited for easy and convenient design

of a step–down switching regulator (buck converter). All

circuits of this series are capable of driving a 1.0A load with

excellent line and load regulation. These devices are avail-

able in fixed output voltages of 3.3V, 5.0V, 12V, and

an adjustable output version.

These regulators were designed to minimize the num-

ber of external components to simplify the power supply

design. Standard series of inductors optimized for use with

the TC2575 are offered by several different inductor manu-

facturers.

Since the TC2575 converter is a switch-mode power

supply, its efficiency is significantly higher in comparison

with popular three-terminal linear regulators, especially with

higher input voltages. In many cases, the power dissipated

is so low, that no heatsinking is required or its size can be

reduced dramatically.

The TC2575 features include a guaranteed

±4% toler-

ance on output voltage within specified input voltages and

output load conditions, and

±10% on the oscillator frequency

(

±2% over 0°C to +125°C). External shutdown is included,

featuring 80

µA (typical) standby current. The output switch

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

shutdown for full protection under fault conditions.

FEATURES

s

3.3V, 5.0V, 12V, and Adjustable Output Versions

s

Adjustable Version Output Voltage Range of

1.23V to 37V

s

Guaranteed 1.0 A Output Current

s

Wide Input Voltage Range; 4.75V to 40V

s

Requires Only 4 External Components

s

52kHz Fixed Frequency Internal Oscillator

s

TTL Shutdown Capability, Low Power Standby Mode

s

High Efficiency

s

Uses Readily Available Standard Inductors

s

Thermal Shutdown and Current Limit Protection

APPLICATIONS

s

Simple and High-Efficiency Step-Down

(Buck) Regulator

s

Efficient Pre–Regulator for Linear Regulators

s

On–Card Switching Regulators

s

Positive to Negative Converters (Buck–Boost)

s

Negative Step-Up Converters

s

Power Supply for Battery Chargers

GENERAL DESCRIPTION

ORDERING INFORMATION

Part

Temperature

Number

Package

Range

TC2575-3.3VAT

5-Pin TO-220

–40 to +125

°C

TC2575-5.0VAT

5-Pin TO-220

–40 to +125

°C

TC2575-12.0VAT* 5-Pin TO-220

–40 to +125

°C

TC2575VAT**

5-Pin TO-220

–40 to +125

°C

TC2575

TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.

PIN CONFIGURATIONS

5-Pin TO-220

Note: * Contact factory for availability

** ADJ = 1.23 To 37V.

1 2 34 5

TC2575