PCA2002U/10AB/1,00

PCA2002U/10AB/1,00 is a 32KHz watch circuit with a programmable output period and pulse width. It is a CMOS integrated circuit for battery-operated wristwatches with a 32KHz quartz crystal as the timing element and a bipolar stepping motor. The quartz crystal oscillator and the frequency divider are optimized for minimum current consumption. A timing accuracy of 1ppm is achieved with a programmable, digital frequency adjustment. The output period and the output pulse width can be programmed. It can be selected between a full output pulse or a chopped output pulse with a duty cycle of 75%. In addition, a stretching pulse can be added to the primary driving pulse. A pad RESET is provided (used for stopping the motor) for accurate time setting and for accelerated testing of the watch. The application includes driver circuits for bipolar stepping motors, high immunity motor drive circuits, and high production volumes.

• Quartz crystal is the only external component required
• Supply voltage range from 1.1 to 3.6V (normal operating mode, Tamb = -10 to +60°C)
• Supply current is 90nA typ (b/w motor pulses, VDD = 1.55V, VSS = 0V, fosc = 32.768KHz, Ta = 25°C)
• Saturation voltage is 150mV typ (Rmotor =2Kohm, Tamb = -10 to +60°C)
• Output impedance (short circuit) is 200 ohm typ (between motor pulses, Imotor <lt/> 1mA, Tamb = 25°C)
• Output frequency is 32Hz typ (VDD = 1.55V, VSS = 0V, fosc = 32.768KHz, Tamb = 25°C)
• Differential output voltage is 1.4V min (RL =1Mohm, CL = 10pF, Tamb = 25°C)
• Rise time and fall time is 1µs typ (RL =1Mohm, CL = 10pF, Tamb = 25°C)
• Average input current is 10nA typ ( pin RESET connected to VDD or VSS, Tamb = 25°C)
• Wire bond die package, ambient temperature range from -10 to +60°C