LT8331

1

8331fa

For more information www.linear.com/LT8331

TYPICAL APPLICATION

FEATURES

DESCRIPTION

Flyback/Inverting Converter

with 0.5A, 140V Switch

The LT®8331 is a current mode DC/DC converter with a

140V, 0.5A switch operating from a 4.5V to 100V input.

With a unique single feedback pin architecture, it is ca-

pable of boost, SEPIC, flyback or inverting configurations.

Burst Mode operation consumes as low as 6μA quiescent

current to maintain high efficiency at very low output cur-

rents, while keeping typical output ripple below 20mV.

The internally-compensated current mode architecture

results in stable operation over a wide range of input and

output voltages and programmable switching frequencies

between 100kHz to 500kHz. A SYNC/MODE pin allows

synchronization to an external clock. It can also be used to

selectbetweenburstorpulse-skippingmodesofoperation.

For increased efficiency, a BIAS pin can accept a second

include frequency foldback and programmable soft-start

for controlling inductor current during start-up.

The LT8331 is available in a thermally-enhanced MSOP

package with four pins removed for high voltage spacings.

48V Output SEPIC Converter

APPLICATIONS

n

Wide Input Voltage Range: 4.5V to 100V

n

Ultralow Quiescent Current and Low Ripple

n

0.5A, 140V Power Switch

n

Positive or Negative Output Voltage Programming

with a Single Feedback Pin

n

Programmable Frequency (100kHz to 500kHz)

n

Synchronizable to an External Clock

n

BIAS Pin for Higher Efficiency

n

Programmable Undervoltage Lockout (UVLO)

n

Thermally-Enhanced High Voltage MSOP Package

n

Industrial and Automotive

n

Telecom

n

Medical Diagnostic Equipment

n

Portable Electronics

L

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

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

owners.

Efficiency and Power Loss

8331 TA01a

•

34.8k

2.2µF

1M

59k

0.1µF

63.4k

1µF

IN

SW1-2

EN/UVLO

LT8331

36V TO

72V

220H

1M

220H

SYNC/MODE

GND

FBX

BIAS

SS

450kHz

4.7µF

×4

1µF

×2

V

RT

EFFICIENCY

POWER LOSS

LOAD CURRENT (mA)

0

50

100

150

200

0

10

20

30

40

50

60

70

80

90

100

0

0.5

1.0

1.5

2.0

8331 TA01b