SIMULATION OF MIXED SWITCHED-CAPACITOR DIGITAL NETWORKS WITH SIGNAL-DRIVEN SWITCHES

This paper considers the simulation of mixed switched-capacitor/digital (SC/D) networks containing capacitors, independent and linear-dependent voltage sources, switches, comparators, and logic gates using a new simulator, SWITCAP2. The switches, in particular, may be controlled by not only periodic waveforms but also by nonperiodic waveforms from the outputs of comparators and logic gates. The signal-dependent modification of network topology through the comparators, logic gates, and signal-driven switches makes the modeling of various nonlinear switched-capacitor circuits possible. Simulation results for a PCM voice encoder, a sigma-delta modulator, a neural network, and a phase-locked loop (PLL) are presented to demonstrate the flexibility of the approach. © 1990 IEEE