UCC2918/81510

LOW ONRESISTANCE HOT SWAP POWER MANAGER

SLUS457C − JULY 2000 - REVISED APRIL 2001

1

POST OFFICE BOX 655303

From 0 A to 4 A

Limit up to 5 A

description

The UCC2918 low on-resistance hot swap power manager provides complete power management, hot swap

capability, and circuit breaker functions. The only components needed to operate the device, other than supply

bypassing, are a timing capacitor and two programming resistors. All control and housekeeping functions are

integrated and externally programmable. These include the fault current level, maximum output sourcing

current, maximum fault time, and startup delay. In the event of a constant fault, the internal fixed 3% duty cycle

ratio limits the average output power. The IFAULT pin allows linear programming of the fault level current from

0 A to 4 A.

functional block diagram

9

8

5

4

13

12

10

6

7

3

2

1

INTERNAL

BIAS

THERMAL

SHUTDOWN

ON TIME

CONTROL

3% DUTY

CYCLE

CHARGE

PUMP

16

15

14

VIN

VIN

VIN

VOUT

VOUT

VOUT

SHTDWN

FAULT

CT

HEAT SINK GND

PINS

GND

IFAULT

IMAX

CURRENT

FAULT LEVEL

OVERLOAD

COMPARATOR

OVERCURRENT

COMPARATOR

REVERSE

COMPARATOR

VOUT

+

20mV

CURRENT SENSE

1.5V

H = OPEN

MAXIMUM

CURRENT

LEVEL

+

+

+

+

+

+

UDG−00101

Copyright

 2001, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

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.

Pin 5 serves as the lowest impedance to the electrical

ground. Pins 4, 12, and 13, serve as heat sink/ground.

These pins should be connected to large etch PCB areas

to help dissipate heat.

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

VIN

VIN

VIN

GND*

GND*

FAULT

SHTDWN

IFAULT

VOUT

VOUT

VOUT

GND*

GND*

NC

CT

IMAX

DP PACKAGE

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