PCF2003DUS: 32 kHz watch circuit with programmable adaptive motor pulse and pulse period
The PCF2003 is a CMOS integrated circuit for battery operated wrist watches with a 32 kHz quartz crystal as timing element and a bipolar 1 Hz stepping motor. The quartz crystal oscillator and the frequency divider are optimized for minimum power consumption. A timing accuracy of 1 ppm is achieved with a programmable, digital frequency adjustment.
To obtain the minimum overall power consumption for the watch, an automatic motor pulse adaptation function is provided. The circuit supplies only the minimum drive current, which is necessary to ensure a correct motor step. Changing the drive current of the motor is achieved by chopping the motor pulse with a variable duty cycle. The pulse period and the range of the variable duty cycle can be programmed to suit different types of motors. The automatic pulse adaptation scheme is based on a safe dynamic detection of successful motor steps.
A pad RESET is provided (used for stopping the motor) for accurate time setting and for accelerated testing of the watch.
Data Sheets (1)
| Name/Description | Modified Date |
|---|---|
| 32 kHz watch circuit with programmable adaptive motor pulse and pulse period (REV 1.0) PDF (246.0 kB) PCF2003 | 20 Oct 2015 |
Packing (1)
| Name/Description | Modified Date |
|---|---|
| PCF2003DUS; Reel dry pack, SMD, 7" Q1/T1 standard product orientation Orderable part number ending ,012 or... (REV 1.1) PDF (272.0 kB) WLCSP8_PCF2003DUS_012 | 25 Nov 2015 |
Ordering Information
| Product | Status | Package version | Application | Function |
|---|---|---|---|---|
| PCF2003DUS | End of Life | NAU000 | ||
| PCF2003DUS/DA | No Longer Manufactured | NAU000 |
Package Information
| Product ID | Package Description | Outline Version | Reflow/Wave Soldering | Packing | Product Status | Part NumberOrdering code(12NC) | Marking | Chemical Content | RoHS / Pb Free / RHF | LeadFree Conversion Date | MSL | MSL LF |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PCF2003DUS/DA |  | Reel 7" Q1/T1 in Drypack | Discontinued | PCF2003DUS/DAAZ (9353 062 43012) | Standard Marking | PCF2003DUS/DA |    | Always Pb-free | NA | NA | ||
| Reel 7" Q1/T1 in Drypack | Withdrawn | PCF2003DUS/DAZ (9353 062 43027) | Standard Marking | PCF2003DUS/DA | | Always Pb-free | NA | NA |
