Channel switchover power multiplexer circuits, and methods of operating the same

A method of controlling a power multiplexer circuit, the method comprising:

• enabling a soft-start amplifier to turn on a first transistor, the first transistor coupled in series with a second transistor to form a first channel between a first input and an output;
• enabling a diode amplifier to regulate a gate voltage of a third transistor, the third transistor coupled in series with a fourth transistor to form a second channel between a second input and an output;
• and
• when the first transistor has turned on:
• disabling the soft-start amplifier,
• enabling a first driver to hold the first transistor on, and
• disabling the diode amplifier.

A power multiplexer circuit, comprising:

• a first transistor having a source coupled to a first power multiplexer input;
• a second transistor having a drain coupled to a drain of the first transistor, and a source coupled to a power multiplexer output;
• a third transistor having a source coupled to a second power supply input;
• a fourth transistor having a drain coupled to a drain of the third transistor, and a source coupled to the power multiplexer input;
• a first amplifier having an output coupled to a gate of the first transistor, a first input coupled to the first power multiplexer input via a first voltage source, and a second input coupled to the power multiplexer output;
• a second amplifier having an output coupled to a gate of the fourth transistor;
• and
• a controller coupled to an enable input of the first amplifier and to an enable input of the second amplifier.