2003 Dec 17

6

Philips Semiconductors

Product specification

32 kHz watch circuit with programmable

adaptive motor pulse

PCA2000; PCA2001

handbook, full pagewidth

MGW352

VDD

VSS

MOTOR

MOT1

N1

P1

D1

RD

N2

P2

P4

P3

MOT2

Fig.5 Simplified diagram of motor driving and step detection circuit.

MGW569

handbook, full pagewidth

tp

td = 0.98 ms

0.98 ms

(motor shorted)

sampling

voltage

IMOT

sampling

voltage

positive detection level

negative detection level

programmable time limit

OTP C4 to C6

sampling

positive detection

negative detection

sampling results

motor shorted

sampling

61

µs

0.49 ms

t

t

t

Fig.6 Step detection sequence and corresponding sampling voltage.