3

2

1 20 19

9 10 11 12 13

4

5

6

7

8

18

17

16

15

14

B Out

V

C

NC

Gnd

A Out

C/S–

C/S+

NC

E/A+

E/A–

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

C/L SS

C/S–

C/S+

E/A+

E/A–

Comp

C

T

Shutdown

V

IN

B Out

V

C

Gnd

A Out

Sync

R

T

V

REF

UC1846-SP

www.ti.com

SLUS871B

– JANUARY 2009 – REVISED OCTOBER 2011

RAD-TOLERANT CLASS-V, CURRENT-MODE PWM CONTROLLER

Check for Samples: UC1846-SP

1

FEATURES

FK PACKAGE

•

QML-V Qualified, SMD 5962-86806

(TOP VIEW)

•

•

Automatic Feed-Forward Compensation

•

Programmable Pulse-by-Pulse Current

Limiting

•

Automatic Symmetry Correction in Push-Pull

Configuration

•

Enhanced Load Response Characteristics

•

Parallel-Operation Capability for Modular

Power Systems

•

Differential Current-Sense Amplifier With Wide

Common-Mode Range

•

Double-Pulse Suppression

•

500-mA (Peak) Totem-pole Outputs

•

±1% Bandgap Reference

•

Undervoltage Lockout

J OR W PACKAGE

(TOP VIEW)

•

Soft-Start Capability

•

Shutdown Terminal

•

500-kHz Operation

(1)

Radiation tolerance is a typical value based upon initial device

qualification with dose rate = 10 mrad/sec. Radiation Lot

Acceptance Testing is available - contact factory for details.

DESCRIPTION

The UC1846 control devices provide all of the necessary features to implement fixed frequency, current mode

control schemes while maintaining a minimum external parts count. The superior performance of this technique

can be measured in improved line regulation, enhanced load response characteristics, and a simpler,

easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current limiting capability,

automatic symmetry correction for push-pull converters, and the ability to parallel

“power modules" while

maintaining equal current sharing.

Protection circuitry includes built-in under-voltage lockout and programmable current limit in addition to soft start

capability. A shutdown function is also available which can initiate either a complete shutdown with automatic

restart or latch the supply off.

Other features include fully latched operation, double-pulse suppression, deadline adjust capability, a

±1%

trimmed bandgap reference, and low outputs in the OFF state.

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright

© 2009–2011, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.