| 摘要 |
<p>A low power consumption switch interface circuit (100) includes a current source (109) for providing switch current (144) having a magnitude dependent on a state of a current range signal (135). An input terminal (142) is provided to conduct the switch current (144) to an external switch (102). A circuit (101, 103, 119) for detecting a signal (141) present at the input terminal (142) provides a measured pulse (127) when the signal (141) is detected. A current range selector (129), coupled to current source (109), outputs a first state of the current range signal (135) while the measured pulse (127) is outputted from the circuit (101, 103, 119), and outputs a second state of the current range signal (135) while the measured pulse (127) is not outputted from the circuit (101, 103, 119). Current source (109) provides the switch current (144) at a first magnitude responsive to the first state of the current range signal (135) and a second magnitude responsive to the second state of the current range signal (135).</p> |
