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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.

LM2670

SNVS036K – APRIL 2000 – REVISED JUNE 2016

1

1 Features

1

•

Efficiency Up to 94%

•

Simple and Easy to Design With (Using Off-the-

Shelf External Components)

•

150-mΩ DMOS Output Switch

•

3.3-V, 5-V, 12-V Fixed Output and Adjustable

(1.2 V to 37 V) Versions

•

50-µA Standby Current When Switched OFF

•

±2% Maximum Output Tolerance Over Full Line

and Load Conditions

•

Wide Input Voltage Range: 8 V to 40 V

•

External Sync Clock Capability

(280 kHz to 400 kHz)

•

260-kHz Fixed Frequency Internal Oscillator

•

–40 to 125°C Operating Junction Temperature

Range

2 Applications

•

Simple-to-Design, High Efficiency (>90%) Step-

Down Switching Regulators

•

Efficient System Preregulator for Linear Voltage

Regulators

•

Battery Chargers

•

Communications and Radio Equipment Regulator

With Synchronized Clock Frequency

3 Description

The LM2670 series of regulators are monolithic

integrated circuits which provide all of the active

functions for a step-down (buck) switching regulator

capable of driving up to 3-A loads with excellent line

and load regulation characteristics. High efficiency

(>90%) is obtained through the use of a low ON-

resistance DMOS power switch. The series consists

of fixed output voltages of 3.3-V, 5-V, and 12-V

output version.

complete design using a minimum number of external

components. The switching clock frequency can be

provided by an internal fixed frequency oscillator

(260 kHz) or from an externally provided clock in the

range of 280 kHz to 400 kHz which allows the use of

physically smaller sized components. A family of

standard inductors for use with the LM2670 are

available from several manufacturers to greatly

simplify the design process. The external sync clock

provides direct and precise control of the output ripple

frequency

for

consistent

filtering

or

frequency

spectrum positioning.

The

LM2670

series

also

has

built-in

thermal

shutdown, current limiting and an ON/OFF control

input that can power down the regulator to a low

50

‑µA quiescent current standby condition. The

output voltage is ensured to a ±2% tolerance.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

LM2670

TO-263 (7)

10.10 mm × 8.89 mm

TO-220 (7)

14.986 mm × 10.16 mm

VSON (14)

6.00 mm × 5.00 mm

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

the end of the data sheet.

Typical Application