LT3477

1

3477fc

TYPICAL APPLICATION

DESCRIPTION

3A, DC/DC Converter

with Dual Rail-to-Rail

Current Sense

FEATURES

APPLICATIONS

(Boost, Inverting, SEPIC, Flyback)

(4mm

× 4mm) QFN and 20-Lead TSSOP Packages

verter with dual rail-to-rail current sense amplifiers and an

internal 3A, 42V switch. It combines a traditional voltage

feedback loop and two unique current feedback loops to

operate as a constant-current, constant-voltage source.

Both current sense voltages are set at 100mV and can be

ficiency of up to 91% can be achieved in typical applications.

The LT3477 features a programmable soft-start function

to limit inductor current during start-up. Both inputs of

the error amplifier are available externally allowing posi-

tive and negative output voltages (boost, inverting, SEPIC,

Flyback). The switching frequency is programmable from

200kHz to 3.5MHz through an external resistor.

Available in thermally enhanced 20-pin (4mm

× 4mm)

QFN and 20-pin TSSOP packages, the LT3477 provides a

complete solution for both constant-voltage and constant-

current applications.

Efficiency

330mA LED Driver With Open LED Protection

FBN

200k

3.3μF

3.3μF

5V

33nF

4.7nF

330mA

3477 TA01a

10k

22k

1k

0.3Ω

SW

10μH

FBP

SS

GND

LT3477

SHDN

SHDN

0

70

75

80

0.4

3477 TA01b

65

60

50

0.1

0.2

0.3

55

90

85

Inverting, Flyback Converters

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.