ZXCT1032

Issue 4 - June 2007

2

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© Zetex Semiconductors plc 2007

Pin description

Typical application circuit

Pinout connections

Pin

Name

Description

1

GND

device. No other pin should go below this voltage.

An external capacitor is connected to this pin and is used to determine

the period for constant-current mode and the timeout before restarting.

To reduce excessive heating during the soft start mode capacitors less

than 220nF are reocmmended.

3

ISET

Determines the load current trip level or constant current level. This can

be driven via a DC voltage or via a µC PWM output.

If left open-circuit, an accurate internal DC reference of 2.1V and source

impedance of 50k

is used to set the voltage on this pin. (External

drivers must take this reference into account.)

4

Flag

This is an active low open collector output that goes low whenever the

event of a shorted load.

5

Drive

This is the output drive pin to the external high side referred switch on

the ZXCT1032, capable of driving PMOS and PNP transistors.

6

IN-

The load referred input to the current monitor control loop.

7

N/C

Not connected

8

IN+

Acts as both the supply pin to the ZXCT1032 and the supply referred

sense input to the current monitor control loop.

Load

ZXCT

1032

IN+

I

SET

GND

IN-

8

6

1

3

Drive

GND

5

2

Flag

µC

4

GND-

ISET

Flag

IN+

1

2

3

4

8

7

6

5

N/C

IN-

Drive

Top view

SO8