ZXCT1008FTA(2007) View Datasheet(PDF) - Diodes Incorporated.

Part Name

Description

Manufacturer

ZXCT1008FTA
(Rev.:2007)

AUTOMOTIVE HIGH-SIDE CURRENT MONITOR

Diodes Incorporated. 

ZXCT1008

Where Rload represents any load including DC

motors, a charging battery or further circuitry that

requires monitoring, Rsense can be selected on

specific requirements of accuracy, size and power

rating.

An additional resistor, Rlim can be added in series

with Rout (figure 1.0), to limit the current from Iout.

Any circuit connected to Vout will be protected from

input voltage transients. This can be of particular

use in automotive applications where load dump

and other common transients need to be

considered. The zener Z1 provides additional

protection for local dump, reverse battery and high

voltage transient incidents.

Assuming the worst case condition of Vout = 0V;

providing a low impedance to a transient, the

minimum value of Rlim is given by:-

Rlim(min) =

Vpk

− Vmax

Ipk

Vpk = Peak transient voltage to be withstood

Vmax = Maximum working Voltage = 20V

Ipk = Peak output current = 40mA

TYPICAL AUTOMOTIVE CIRCUIT APPLICATION

Figure 1.0

ZXCT1009 with additional current limiting Resistor Rlim

and zener Z1

The maximum value of Rlim is set by Vin(min),

Vout(max) and the dropout voltage (see transfer

characteristic on page 3) of the ZXCT1009 :-

Rlim(max)

=

Rout[Vin(min) − (Vdp + Vout(max))]

Vout (max)

Vin(min) = Minimum Supply Operating Voltage

Vdp = Dropout Voltage

Vout (max) = Maximum Operating Output Voltage

ISSUE 4 - JULY 2007

6

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