LT3970/LT3970-3.3/LT3970-5

1

3970fa

TYPICAL APPLICATION

DESCRIPTION

40V, 350mA Step-Down

Regulator with 2.5µA

Quiescent Current and

Integrated Diodes

The LT

switching regulator that accepts a wide input voltage

range up to 40V, and consumes only 2.5μA of quiescent

current. A high efficiency switch is included on the die

along with the catch diode, boost diode, and the neces-

sary oscillator, control and logic circuitry. Low ripple Burst

Mode operation maintains high efficiency at low output

currents while keeping the output ripple below 5mV in a

typical application. Current mode topology is used for fast

transient response and good loop stability. A catch diode

current limit provides protection against shorted outputs

and overvoltage conditions. An enable pin with accurate

threshold is available, producing a low shutdown current

90% of the programmed output voltage. The LT3970 is

available in small 10-pin MSOP and 3mm × 2mm DFN

packages.

5V Step-Down Converter

FEATURES

APPLICATIONS

BOOST

LT3970

SW

EN

PG

RT

0.22μF

22pF

22μF

2.2μF

6V TO 40V

5V

350mA

1M

316k

226k

f = 600kHz

22μH

BD

FB

GND

OFF ON

3490 TA01a

Efficiency

L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks

of Linear Technology Corporation. All other trademarks are the property of their respective

owners.

LOAD CURRENT (mA)

50

70

90

40

60

80

0.01

1

10

100

3970 TA01b

1

10

100

1000

0.01

0.1

0.1