A Switched Decoupling Capacitor Circuit for On-Chip Supply Resonance Damping

A low power switched decoupling capacitor circuit is proposed to suppress on-chip resonant supply noise. Compared to previous analog techniques, the proposed digital implementation achieves a 9X reduction in quiescent power with improved tolerance to PVT variation and tuning capability for optimal switching threshold. Measurements from a 0.13μm test chip show an 11X boost in effective decap value and a 9.8dB suppression in resonant supply noise by using the proposed circuit.