An integrated circuit includes an array of write assist circuits electrically connected to a memory cell array. Each write assist circuit is configured to set an operating voltage of a corresponding memory cell. Each write assist circuit is configured to receive at least a first control signal, and generate an output signal at least in response to the first control signal. The output signal controlling the operating voltage of the corresponding memory cell. Each write assist circuit includes a programmable voltage tuner. The programmable voltage tuner includes a first P-type transistor and a second P-type transistor coupled to the first P-type transistor. A first terminal of the first P-type transistor is configured as a first input node to receive a first select control signal. A first terminal of the second P-type transistor is configured as a second input node to receive a second select control signal.