Abstract: A system includes an output terminal and a linear switch circuit coupled to the output terminal. The linear switch circuit includes a first power field-effect transistor (FET) having: a first channel width; a control terminal; a first current terminal; and a second current terminal, wherein the second current terminal is coupled to the output terminal. The linear switch circuit also includes a second power FET having: a second channel width smaller than the first channel width; a control terminal; a first current terminal coupled to the first current terminal of the first power FET; and a second current terminal coupled to the output terminal. The system also comprises a control circuit coupled to the control terminal of the first power FET and to the control terminal of the second power FET. The control circuit detects a drain-to-source voltage (VDS) saturation condition and controls the first and second power FETs accordingly.

Abstract: A system includes an output terminal and a linear switch circuit coupled to the output terminal. The linear switch circuit includes a first power field-effect transistor (FET) having: a first channel width; a control terminal; a first current terminal; and a second current terminal, wherein the second current terminal is coupled to the output terminal. The linear switch circuit also includes a second power FET having: a second channel width smaller than the first channel width; a control terminal; a first current terminal coupled to the first current terminal of the first power FET; and a second current terminal coupled to the output terminal. The system also comprises a control circuit coupled to the control terminal of the first power FET and to the control terminal of the second power FET. The control circuit detects a drain-to-source voltage (VDS) saturation condition and controls the first and second power FETs accordingly.

Abstract: A system includes an output terminal and a linear switch circuit coupled to the output terminal. The linear switch circuit includes a first power field-effect transistor (FET) having: a first channel width; a control terminal; a first current terminal; and a second current terminal, wherein the second current terminal is coupled to the output terminal. The linear switch circuit also includes a second power FET having: a second channel width smaller than the first channel width; a control terminal; a first current terminal coupled to the first current terminal of the first power FET; and a second current terminal coupled to the output terminal. The system also comprises a control circuit coupled to the control terminal of the first power FET and to the control terminal of the second power FET. The control circuit detects a drain-to-source voltage (VDS) saturation condition and controls the first and second power FETs accordingly.

Abstract: In described examples, a power interface subsystem includes power transistors, each having: a conduction path coupled between a battery terminal and an accessory terminal; and a control terminal. A differential amplifier has: a first input coupled to the battery terminal; a second input coupled to the accessory terminal; and an output node. An offset voltage source is coupled to cause an offset of a selected polarity at one of the inputs to the differential amplifier. The offset has a first polarity in a first operating mode and a second polarity in a second operating mode. Gate control circuitry is coupled to apply a control level at the control terminal(s) of selected one(s) of the power transistors responsive to a voltage at the output node, and to apply an off-state control level to the control terminal(s) of unselected one(s) of the power transistors.

Abstract: A system includes an output terminal and a linear switch circuit coupled to the output terminal. The linear switch circuit includes a first power field-effect transistor (FET) having: a first channel width; a control terminal; a first current terminal; and a second current terminal, wherein the second current terminal is coupled to the output terminal. The linear switch circuit also includes a second power FET having: a second channel width smaller than the first channel width; a control terminal; a first current terminal coupled to the first current terminal of the first power FET; and a second current terminal coupled to the output terminal. The system also comprises a control circuit coupled to the control terminal of the first power FET and to the control terminal of the second power FET. The control circuit detects a drain-to-source voltage (VDS) saturation condition and controls the first and second power FETs accordingly.

Abstract: In described examples, a power interface subsystem includes power transistors, each having: a conduction path coupled between a battery terminal and an accessory terminal; and a control terminal. A differential amplifier has: a first input coupled to the battery terminal; a second input coupled to the accessory terminal; and an output node. An offset voltage source is coupled to cause an offset of a selected polarity at one of the inputs to the differential amplifier. The offset has a first polarity in a first operating mode and a second polarity in a second operating mode. Gate control circuitry is coupled to apply a control level at the control terminal(s) of selected one(s) of the power transistors responsive to a voltage at the output node, and to apply an off-state control level to the control terminal(s) of unselected one(s) of the power transistors.

Abstract: In described examples, a power interface subsystem includes power transistors, each having: a conduction path coupled between a battery terminal and an accessory terminal; and a control terminal. A differential amplifier has: a first input coupled to the battery terminal; a second input coupled to the accessory terminal; and an output node. An offset voltage source is coupled to cause an offset of a selected polarity at one of the inputs to the differential amplifier. The offset has a first polarity in a first operating mode and a second polarity in a second operating mode. Gate control circuitry is coupled to apply a control level at the control terminal(s) of selected one(s) of the power transistors responsive to a voltage at the output node, and to apply an off-state control level to the control terminal(s) of unselected one(s) of the power transistors.

Abstract: In described examples, a transistor has: a source and a drain coupled between a supply voltage and an output terminal; and a gate terminal. A charge pump has: an output node coupled to the gate terminal; and a clock input. An oscillator is coupled to generate a clock signal. A clock enable circuit is coupled to: receive the clock signal; and selectively output the clock signal to the clock input, responsive to an enable signal. A comparator is coupled to output the enable signal in response to a comparison between a reference current and a current through a series resistor. The series resistor is coupled to the gate terminal.

Abstract: In described examples, a transistor has: a source and a drain coupled between a supply voltage and an output terminal; and a gate terminal. A charge pump has: an output node coupled to the gate terminal; and a clock input. An oscillator is coupled to generate a clock signal. A clock enable circuit is coupled to: receive the clock signal; and selectively output the clock signal to the clock input, responsive to an enable signal. A comparator is coupled to output the enable signal in response to a comparison between a reference current and a current through a series resistor. The series resistor is coupled to the gate terminal.

Abstract: In described examples, a power interface subsystem includes power transistors, each having: a conduction path coupled between a battery terminal and an accessory terminal; and a control terminal. A differential amplifier has: a first input coupled to the battery terminal; a second input coupled to the accessory terminal; and an output node. An offset voltage source is coupled to cause an offset of a selected polarity at one of the inputs to the differential amplifier. The offset has a first polarity in a first operating mode and a second polarity in a second operating mode. Gate control circuitry is coupled to apply a control level at the control terminal(s) of selected one(s) of the power transistors responsive to a voltage at the output node, and to apply an off-state control level to the control terminal(s) of unselected one(s) of the power transistors.