In described examples, a circuit includes a switch. The switch includes first transistors and second transistors. A voltage generation circuit is coupled to the switch. A level shifter is coupled to the voltage generation circuit and is configured to receive a control signal. A logic unit is coupled to the level shifter and the voltage generation circuit. The logic unit is configured to generate a secondary signal. The first transistors are configured to receive the control signal, and the second transistors are configured to receive the secondary signal.