embodiments of threshold adjustment circuits are disclosed . an example circuit includes a first differential pair of first and second thin oxide transistors . the first and second thin oxide transistors decrease a dc voltage component of a first and / or second component of an input signal of the circuit . the example circuit further includes a second differential pair of third and fourth thin oxide transistors . the second and third thin oxide transistors increase a dc voltage component of the first and / or the second component of the input signal . the example circuit also includes a power supply that provides a supply voltage to the circuit , the power supply having a voltage level above a reliability level of the thin oxide transistors . in the example circuit , each of the differential pair thin oxide transistors is switched by a signal that keeps each of the first , second , third , and fourth thin oxide transistors operating in saturation .