PWM DC Motor Regulator – Data Sheet

AS8410

Rev. 1.0, December 2000

4.1.8.2

Over / Under Voltage Detection and Protection

The over / under voltage detection is used to prevent undefined system status.

Over or under voltage detected:

Handling:

a) switch off the motor

b) reuse the input set value, if the supply voltage returns in the

permissible range

Symbol

Parameter

min

typ

max

Unit

Note

Vbat

Monitored supply voltage

5

12

50

V

Threshold voltage of the under voltage

detection

6,2

6,50

6,7

V

falling

Threshold voltage of the over voltage

detection

32

33

34

V

rising

4.1.8.3

Over Temperature Detection and Protection

The over temperature detection is realised with an external temperature sensor (e.g. NTC re-

sistor) connected to the pin TP and the supply VDD. The threshold value of the temperature

Symbol

Parameter

min

typ

max

Unit

Note

VDD

5V supply at pin VDD

4,7

5,00

5,3

V

Threshold voltage of the temperature

detection

0.5*VDD

V

1

50

mV

1

Cross current of the external resistor divider must be > 1 mA

Handling of the over temperature failure:

-

The Over Temperature reaction: 100 % duty ratio of the FET-driver output (perma-

nent switch on the motor) as long as the temperature is higher than the predefined

threshold value (typical automotive application, the heating source is not the electri-

cal system but the combustion engine to be cooled).

-

The Over Temperature reaction: The motor is regulated down to not cross the pre-

defined temperature threshold (like a thermostat if the heating source is the electrical

system itself).

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