| 摘要 |
PURPOSE:To prevent the waste of power, and also, to miniaturize a circuit by turning OFF a constant-current supplying means such as a pull-up resistance and a constant-current driver, etc., in accordance with an output signal level in input circuit and/or the output circuit of an open drain (or open collector) structure incorporating a pull-up circuit. CONSTITUTION:The title circuit is provided with a switching circuit SW for interrupting a current for flowing to a pull-up resistance RP, when an output signal level obtained from an output terminal Tout is 'low'. Also, an unnecessary current is eliminated thereby. Also, when the output level is 'high', the switching circuit SW is closed, therefore, a regular pull-up operation is executed. |
