LT1737IS(RevA) Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

Список матч

LT1737IS
(Rev.:RevA)

High Power Isolated Flyback Controller

Linear Technology 

LT1737

High Power

Isolated Flyback Controller

FEATURES

■ Drives External Power MOSFET

■ Supply Voltage Range: 4.5V to 20V

■ Flyback Voltage Limited Only by

External Components

■ Senses Output Voltage Directly from Primary Side

Winding—No Optoisolator Required

■ Switching Frequency from 50kHz to 250kHz

with External Capacitor

■ Moderate Accuracy Regulation Without User Trims

■ Regulation Maintained Well into Discontinuous Mode

■ External ISENSE Resistor

■ Optional Load Compensation

■ Optional Undervoltage Lockout

■ Shutdown Feature Reduces IQ to 50µA Typ

■ Available in 16-Pin GN and SO Packages

U

APPLICATIO S

■ Isolated Flyback Switching Regulators

■ Medical Instruments

■ Instrumentation Power Supplies

DESCRIPTIO

The LT®1737 is a monolithic switching regulator control-

ler specifically designed for the isolated flyback topology.

It drives the gate of an external MOSFET and is generally

powered from a DC supply voltage. Output voltage feed-

back information may be supplied by a variety of methods

including a third transformer winding, the primary wind-

ing or even direct DC feedback (see Applications Informa-

tion). Its gate drive capability, coupled with a suitable

external MOSFET and other power path components, can

deliver load power up to tens of Watts.

The LT1737 has a number of features not found on other

isolated flyback controller ICs. By utilizing current mode

switching techniques, it provides excellent AC and DC line

regulation. Its unique control circuitry can maintain regu-

lation well into discontinuous mode in most applications.

Optional load compensation circuitry allows for improved

load regulation. An optional undervoltage lockout pin

halts operation when the application input voltage is too

low. An optional external capacitor implements a soft-

start function.

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

All other trademarks are the property of their respective owners.

TYPICAL APPLICATIO

Q1

2N3906

D2

BAS16

R2

35.7k

1%

240k

33k

12V-18V to Isolated 15V Converter

VIN

C1 +

22µF

T1

D1

COILTRONICS MBRS1100

CTX150-4

C3

0.1µF

•

150µH

150µH

•

+ C2

33µF

VOUT = 15V

IOUT = 300mA

R4

7.5k

R3

3.01k

1%

FB

VC

OSCAP

UVLO

VCC

LT1737

tON ENDLY MINENAB ROCMP RCMPC

SGND

GATE

ISENSE

PGND

1nF

47pF 75k 150k 100k 4.7k

0.1µF

M1

IRFL014

R1

0.27Ω

NOTE: SEE APPLICATIONS

INFORMATION FOR ADDITIONAL

COMPONENT SPECIFICATIONS

1737 TA01

1737fa

1

Share Link: