zxct1032 Zetex Semiconductors plc., zxct1032 Datasheet - Page 6

• Manufacturer Part Number: zxct1032
• Description: Zxct1032 - High-side Inrush And Current Limit Controller
• Manufacturer: Zetex Semiconductors plc.

Application information
ZXCT1032 block diagram and description
Operation of the ZXCT1032
1 After power-up, the timing capacitor (C
Issue 4 - June 2007
© Zetex Semiconductors plc 2007
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
the load current allowing it to increase gradually (soft-start mode) as the voltage on C
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
capacitive loads are driven and/or large C
C
2.5
1.5
0.5
T
(1)
(3)
(2)
3
2
1
0
0
V
R
C
V
Trip current = 1A
GND
IN+
ISET
SENSE
T
I
C
= 220nF
SET
IN+
(8)
= 18V
T
= 2.1V
= 0.2
I
200 A
I
3.3 A 2.1V
CT-CHG
CT DIS
R
-
SENSE
0.5
+
50k
ZXCT1032 Start up characteristic
-
V
(6)
IN-
ISET
-
ZXCT1032
1
T
) is charged up by a 200µA current source. This causes
T
80mV
time - ms
is used.
+
+
+
-
-
-
6
10*V
1.5
SENSE
I
2
LOAD
Drive
Flag
V
CT
(4)
(5)
ZXCT1032
Load
www.zetex.com
2.5
1.2
1
0.8
0.6
0.4
0.2
0
T