| 摘要 |
A linear voltage regulator is provided which has a pair of complementary power transistors connected “back to back” in series between a voltage input and a voltage output. A current sense circuit including a current sense resistor is connected in parallel across one of the power transistors, such as the one connected to the voltage input. As long as the voltage drop in the current sense circuit remains small, i.e. less than app. 0.7V, the current flowing through the bulk diode of the power transistor remains negligible and the entire output current flows through the current sense circuit. For higher output currents the voltage drop across the current sense circuit is limited by the parallel bulk diode of the power transistor. The current sense resistor can be dimensioned to generate a relatively high voltage drop of e.g. 100 mV, and a high accuracy of open load detection is achieved without the requirement for a high precision comparator.
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