LT3751 Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

производитель

LT3751

Capacitor Charger Controller with Regulation

Linear Technology 

LT3751

Capacitor Charger

Controller with Regulation

FEATURES

DESCRIPTION

n Charges Any Size Capacitor

n Low Noise Output in Voltage Regulation Mode

n Stable Operation Under a No-Load Condition

n Integrated 2A MOSFET Gate Driver with Rail-to-Rail

Operation for VCC ≤ 8V

n Selectable 5.6V or 10.5V Internal Gate Drive

Voltage Clamp

n User-Selectable Over/Undervoltage Detect

n Easily Adjustable Output Voltage

n Primary or Secondary Side Output Voltage Sense

n Wide Input VCC Voltage Range (5V to 24V)

n Available in a 20-Pin QFN 4mm × 5mm

APPLICATIONS

n High Voltage Regulated Supply

n High Voltage Capacitor Charger

n Professional Photoflash Systems

n Emergency Strobe

n Security/Inventory Control Systems

n Detonators

The LT®3751 is a high input voltage capable flyback con-

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

undervoltage lockouts for both VCC and VTRANS. A typical

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

LT3751 has shut down due to either VCC or VTRANS voltage

exceeding the user-programmed supply tolerances.

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.

TYPICAL APPLICATION

DANGER HIGH VOLTAGE! OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY

VTRANS

24V

VCC

24V

330μF

s2

40.2k

OFF ON

10μF TO

MICRO

374k

VTRANS

475k

374k

VCC 475k

RVTRANS

CHARGE

RDCM

CLAMP

RVOUT

VCC LT3751

DONE

FAULT

HVGATE

LVGATE

CSP

UVLO1

OVLO1

CSN

UVLO2

OVLO2

GND

FB

RBG

T1

1:10

D1

10μF

•

×2

18.2k •

40.2k

VCC

6mΩ

10nF

+

0.47μF

732Ω

500V

0 TO 150mA

100μF

715k

1.74k

3751 TA01a

Regulation Mode Load Regulation

and Efficiency vs Load Current

500

90

498

84

496

78

494

72

492

490

0

66

OUTPUT VOLTAGE

EFFICIENCY

60

50

100

150

LOAD CURRENT (mA)

3751 TA01b

3751f

1

Share Link: