
NXP Semiconductors.
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.
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.