Abstract: A full adder circuit includes a carry out generating circuit and a sum bit generating circuit. The carry out generating circuit is configured to generate a first output signal based on a first input signal, a second input signal and a third input signal. The sum bit generating circuit is configured to receive the first output signal and generate a second output signal based on the first input signal, the second input signal, the third input signal and the first output signal. The first output signal and the second output signal provide results of an arithmetic operation on the first input signal, the second input signal and the third input signal. The sum bit generating circuit includes a first pull-up network and a first pull-down network. There are at most two stacked transistors in at one or both of the first pull-up network and the first pull-down network.

Abstract: A full adder circuit includes a carry out generating circuit and a sum bit generating circuit. The carry out generating circuit is configured to generate a first output signal based on a first input signal, a second input signal and a third input signal. The sum bit generating circuit is configured to receive the first output signal and generate a second output signal based on the first input signal, the second input signal, the third input signal and the first output signal. The first output signal and the second output signal provide results of an arithmetic operation on the first input signal, the second input signal and the third input signal. The sum bit generating circuit includes a first pull-up network and a first pull-down network. There are at most two stacked transistors in at one or both of the first pull-up network and the first pull-down network.

Abstract: A delay cell for generating a desired delay exceeding a minimum delay defined in a standard cell library is provided, which includes a delay element and an output inverter. The delay element receives an input signal to generate an internal signal with a propagation delay relative to the input signal, which includes a P-type transistor, a first resistor, a second resistor, and an N-type transistor. The P-type transistor applies a supply voltage to the first resistor by the input signal. The first resistor is coupled between the P-type transistor and the output inverter. The second resistor is coupled to the output inverter and coupled to the ground through the N-type transistor by the input signal. The output inverter receives the internal signal to generate an output signal with the desired delay, which is dominated by the propagation delay, relative to the input signal.

Abstract: A delay cell for generating a desired delay exceeding a minimum delay defined in a standard cell library is provided, which includes a delay element and an output inverter. The delay element receives an input signal to generate an internal signal with a propagation delay relative to the input signal, which includes a P-type transistor, a first resistor, a second resistor, and an N-type transistor. The P-type transistor applies a supply voltage to the first resistor by the input signal. The first resistor is coupled between the P-type transistor and the output inverter. The second resistor is coupled to the output inverter and coupled to the ground through the N-type transistor by the input signal. The output inverter receives the internal signal to generate an output signal with the desired delay, which is dominated by the propagation delay, relative to the input signal.