1998 Apr 21

2

Philips Semiconductors

Product specification

32 kHz watch circuits with adaptive motor

pulse

PCA148x series

FEATURES

• 32 kHz oscillator, amplitude regulated with excellent

frequency stability

• High immunity of the oscillator to leakage currents

• Time calibration electrically programmable and

reprogrammable (via EEPROM)

• A quartz crystal is the only external component required

• Very low current consumption; typically 170 nA

• Output for bipolar stepping motors of different types

• Up to 50% reduction in motor current compared with

conventional circuits, by self adaption of the motor pulse

width in accordance with the required torque of the

motor

• No loss of motor steps possible because of on-chip

detection of the induced motor voltage

• Indication for battery end-of-life

• Stop function for accurate timing

• Power-on reset for fast testing

• Various test modes for testing the mechanical parts of

the watch and the IC.

GENERAL DESCRIPTION

The PCA148x series devices are CMOS integrated circuits

specially suited for battery-operated,

quartz-crystal-controlled wrist-watches, with a bipolar

stepping motor.

ORDERING INFORMATION

Note

1. Figure 1 and Chapter “Package outline” show details of standard package, available for large orders only.

Chapter “Chip dimensions and bonding pad locations” shows exact pad locations for other delivery formats.

TYPE

NUMBER

NAME

DESCRIPTION

VERSION

PCA1485U/7

−

chip with bumps on tape

−

PCA1486U/7

−

chip with bumps on tape

−

PCA1486U/10

−

chip on foil

−

PCA1487U/10

−

chip on foil

−

PINNING

SYMBOL

PIN

DESCRIPTION

1

ground (0 V)

TEST

2

test output

OSC IN

3

oscillator input

OSC OUT

4

oscillator output

5

supply voltage

M1

6

motor 1 output

M2

7

motor 2 output

RESET

8

reset input

Fig.1 Pin configuration, PCA148xT, (PMFP8).

1

2

3

4

8

7

6

5

PCA148xT

VSS

TEST

OSC IN

OSC OUT

RESET

M2

M1

VDD

MSA968