A Low-Power Sample-and-Hold Programmable Voltage Reference Based on Ripple Monitoring

This paper proposes a dual-output Sample-and-Hold (SH) ultra low-power programmable voltage reference (SH-PVR). Our mixed-signal system regulates the ripple voltage on the output channels due to the leakage current, by monitoring the amplified ripple on a channel replica. The refresh frequency of the references is minimized for the minimum current consumption, while maintaining the ripple specification. Designed and implemented in TSMC 180-nm CMOS technology, the SH-PVR provides two references, with a programmability range [0.5 - 2] $\mathbf{V}$ , and a step size of 50 mV. The system achieves a current consumption of 330 nA, with an output ripple below 10 $\mu \mathbf{V}$ , and it is suitable for ultra low-power devices for IoT, wearable, and implantable applications.