PWM DC Motor Regulator – Data Sheet

AS8410

Rev. 1.0, December 2000

4.1.6

Oscillator, Reference Voltage / Current Generator

The oscillator is used to control the PWM generator and the charge pump with a frequency of

typical 18 kHz.

Ω at this pin gen-

erates the reference current. This reference current is used for other functions of this chip too

(see section 3).

Symbol

Parameter

min

typ

max

Unit

Note

Reference voltage at pin OSC

0.96

1.00

1.04

V

Oscillator frequency

17,0

18,0

19,0

kHz

Rise or fall time of the clock

100

ns

Reference current

9,6

10,0

10,4

µA

1

4.1.7

5V Regulator (bandgap reference)

The 5V-regulator generates the supply voltage for all internal low voltage blocks and the rough

supply can also be used externally (e.g. for the temperature sensor at pin TP).

This externally usable 5 V will be switched off in the sleep mode.

Symbol

Parameter

min

typ

max

Unit

Note

Vbat

Supply voltage of the regulator

6,5

12

35

V

VDD

Regulated voltage

4,7

5,0

5,3

V

1

3

mA

4.1.8

Failures Detection, Failure Handling Procedures

Three different kinds of failure detections and protections are implemented:

1. Failure detection of the load circuit (DC motor and power FET)

1.1 Over current detection and protection

1.2 No load detection of the motor and protection

1.3 Open wire detection (motor or power switch)

1.4 Short circuit of the power switch detection

1.5 Blocked motor detection and protection

1.6 Short-circuited motor segments detection and protection

1.7 Protection of the power FET and the ASIC, if the motor works in generator mode

2. Failure detection of the supply voltage Vbat (Over- / Under Voltage)

3. Over Temperature detection and protection in two modes