A circuit comprises a first node, a second node, a sense amplifier, at least one first transistor, at least one second transistor, and one or a combination of a first control circuit and a second control circuit. The first control circuit is configured to generate a first control signal for at least one first gate of the at least one first transistor. The first control signal is capable of having a first voltage level lower than a first operational voltage. The second control circuit is configured to generate a second control signal for at least one second gate of the at least one second transistor. The second control signal is capable of having a second voltage level higher than a second operational voltage.