Philips Semiconductors
32 kHz watch circuits with adaptive motor
pulse
Product specification
PCA146x 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 to match the required torque of the motor
• No loss of motor steps possible because of on-chip
detection of the induced motor voltage
• Detector for lithium or silver-oxide battery voltage levels
• 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 PCA146x series devices are CMOS integrated circuits
specially suited for battery-operated,
quartz-crystal-controlled wrist-watches, with a bipolar
stepping motor.
ORDERING INFORMATION
TYPE
NUMBER
PCA1 461U
PCA1 461U/10
PCA1 462U
PCA1 462U/7
PCA1 462U/10
PCA1 463U
PCA1 463U/10
PCA1 465U/10
PCA1 465U/7
PCA1 467U/10
NAME
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chip in tray
chip on foil
chip in tray
chip with bumps on tape
chip on foil
chip in tray
chip on foil
chip on foil
chip with bumps on tape
chip on foil
PACKAGE(1)
DESCRIPTION
VERSION
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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.
1998 Apr 21
2