ZXCT1032

Issue 4 - June 2007

6

www.zetex.com

© Zetex Semiconductors plc 2007

Application information

ZXCT1032 block diagram and description

Operation of the ZXCT1032

the output amplifier's drive pin to fall in voltage, progressively turning on the PMOS transistor.

The load current is monitored by the current monitor and the amplifier control loop controls

increases. During the soft-start phase the load current will start to build up while there is a

large voltage across the pass MOSFET; this can lead to large power dissipation if large

ZXCT1032

Load

Flag

Drive

IN+

IN-

C

T

C

T

GND

200 A

3.3 A

2.1V

80mV

(1)

(2)

(3)

(4)

(5)

(6)

(8)

R

SENSE

I

CT-CHG

I

CT DIS

50k

-

-

+

+

+

+

-

-

-

-

ZXCT1032 Start up characteristic

0

0.5

1

1.5

2

2.5

3

0

0.5

1

1.5

2

2.5

time - ms

0

0.2

0.4

0.6

0.8

1

1.2

Trip current = 1A