This data sheet details the features and characteristics of the PCA148x series 32 kHz watch circuits.
The PCA148x series are CMOS integrated circuits designed for battery‑operated quartz‑crystal wrist watches that drive bipolar stepping motors. They provide a 32 kHz amplitude‑regulated oscillator with excellent frequency stability and very low current consumption (≈170 nA). The IC requires only a quartz crystal as an external component and includes on‑chip detection of motor voltage to prevent loss of steps.
The device generates six motor‑pulse stages, automatically adapting pulse width to the required torque. When a step is missed, a correction sequence is triggered, and battery end‑of‑life is indicated by a special pulse pattern. Detailed pin configurations, functional descriptions, and detection criteria are included in the datasheet.
| Oscillator frequency | 32 kHz |
|---|---|
| Current consumption | 170 nA (typical) |
| Motor output type | Bipolar stepping motor |
| Motor pulse stages | 6 (stage 1 to 6) |
| Duty factor range | 43.75 % – 75 % |
The IC typically consumes about 170 nA of current.
It provides six motor‑pulse stages, numbered 1 through 6.
Only a quartz crystal is needed as an external component.