| 摘要 |
PROBLEM TO BE SOLVED: To provide a combination line driver/cable detector apparatus having automatic impedance matching and load detection.SOLUTION: A buffer amplifier has a power-on state and a sleep state. During regular operation, a coupling state of a load to an output node is detected using a feedback voltage. In a sleep mode and in a power collapse mode, a detection current is injected into the output node, to produce a voltage, and the coupling state of the load is detected from the voltage. Optionally, the detection current and detection of the voltage on the output node is enabled by a low duty cycle clock. Optionally, signals generated in detecting the coupling state are qualified through a debounce circuit.SELECTED DRAWING: Figure 1 |
