Channel switchover power multiplexer circuits, and methods of operating the same are disclosed. An example power multiplexer a first transistor coupled to a first input, a second transistor coupled to the first transistor to couple a first voltage at the first input to an output, a third transistor coupled to a second input, a fourth transistor coupled to the third transistor to couple a second voltage at the second input to the output, a diode amplifier to provide a third voltage to a gate of the first transistor to block a reverse current, and a soft-start amplifier to provide a fourth voltage to a gate of the fourth transistor to turn on (with adjustable VOUT ramp rate) the fourth transistor with a constant ramp rate.