Steady-State Design Equations of Cross-Coupled Charge Pumps and Application to 28 nm FDSOI Technology

This paper presents model equations of a Cross-Coupled Charge Pump (CC-CP) operating in steady-state conditions, based on a Thévenin equivalent circuit. The model is derived under the assumption of zero net charge transfer of the circuit dynamics. Equations for the mean voltage values of each fly-capacitor are obtained. These equations are useful for the proper sizing of the switching and capacitive elements, avoiding unnecessary area overhead of transistors while guaranteeing functionality. The model also provides ripple equations for both the Fast and Slow Switching Limits. The models are validated against ideal Spectre simulations of a CC-CP and an implementation in 28 nm FDSOI technology.