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.
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PCF2003DUSクイック・リファレンス ドキュメンテーションの種類.
2 ドキュメント
コンパクトリスト
この選択アイテムには該当する結果がありません。
セキュアファイルの読み込み中、しばらくお待ちください。
2 ドキュメント
コンパクトリスト
2 設計・ファイル
セキュアファイルの読み込み中、しばらくお待ちください。
2 設計・ファイル