UCC1919

UCC2919

UCC3919

07/99

FEATURES

• Precision Fault Threshold

Drive

• Differential Sense Inputs

• Programmable Average Power Limiting

• Programmable Linear Current Control

• Programmable Fault Time

• Fault Output Indicator

• Manual and Automatic Reset Modes

• Shutdown Control w/Programmable

Softstart

• Undervoltage Lockout

• Electronic Circuit Breaker Function

3V to 8V Hot Swap Power Manager

10

7

5

6

11

8

9

2

1

12

14

4

GND

CHARGE

PUMP

DRIVER

UVLO

VDD

+

–

UVLO

+

–

+

–

200mV

LINEAR

CURRENT

AMPLIFIER

OVERLOAD

COMPARATOR

S

R

Q

Q

RESET

DOMINANT

SET

DOMINANT

+

–

+

–

1.5V

0.5V

1.2

µA

+

1.5v

13

VDD

36

µA

50mV

VDD

CSP

CSN

IMAX

IBIAS

PL

CT

FLT

GATE

CAP

LR

SD

UVBIAS

VDD

1X

OVERCURRENT

COMPARATOR

UVBIAS

S

R

Q

Q

S

R

Q

Q

FLT

SD

FLT

SD

1X

BLOCK DIAGRAM

UDG-98123

DESCRIPTION

The UCC3919 family of Hot Swap Power Managers provide complete

power management, hot swap, and fault handling capability. The

UCC3919 features a duty ratio current limiting technique, which pro-

vides peak load capability while limiting the average power dissipa-

tion of the external pass transistor during fault conditions. The

UCC3919 has two reset modes, selected with the TTL/CMOS com-

patible L/R pin. In one mode, when a fault occurs the IC repeatedly

tries to reset itself at a user defined rate, with user defined maximum

output current and pass transistor power dissipation. In the other

mode the output latches off and stays off until either the L/R pin is re-

set or the shutdown pin is toggled. The on board charge pump circuit

provides the necessary gate voltage for an external N-channel power

FET.

Note: Pins shown for 14-pin package.

application

INFO

available