LT3751

1

3751f

TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

Capacitor Charger

Controller with Regulation

troller designed to rapidly charge a large capacitor to a

user-adjustable target voltage set by the transformer turns

ratio and three external resistors. An optional feedback pin

can be used to provide a low noise high-voltage regulated

output.

The LT3751 has an integrated rail-to-rail MOSFET gate

driver that allows for efficient operation down to 4.75V.

A low 106mV differential current sense threshold voltage

accurately limits the peak switch current. Added protec-

tion is achieved with user-selectable overvoltage and

application can charge a 1000μF capacitor to 500V in less

than one second.

The CHARGE pin is used to initiate a new charge cycle and

provides ON/OFF control. The DONE pin indicates when the

capacitor has reached its programmed value and the part

has stopped charging. The FAULT pin indicates when the

exceeding the user-programmed supply tolerances.

Voltage Clamp

× 5mm

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

trademarks are the property of their respective owners. Protected by U.S. Patents including

6518733 and 6636021.

CHARGE

CLAMP

DONE

FAULT

UVLO1

OVLO1

UVLO2

OVLO2

RDCM

HVGATE

LVGATE

CSP

CSN

FB

T1

1:10

D1

500V

0 TO 150mA

24V

10μF

×2

3751 TA01a

LT3751

DANGER HIGH VOLTAGE! OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY

GND

RBG

40.2k

OFF ON

330μF

2

24V

10μF

•

•

18.2k

40.2k

6mΩ

+

100μF

715k

1.74k

10nF

732Ω

TO

MICRO

0.47μF

374k

475k

475k

374k

LOAD CURRENT (mA)

0

500

498

494

496

492

490

90

84

72

78

66

60

100

50

3751 TA01b

150

OUTPUT VOLTAGE

EFFICIENCY

Regulation Mode Load Regulation

and Efficiency vs Load Current