Abstract: Aspects of the present disclosure include systems, methods, devices, and circuits for fast settling of a bias node. Consistent with some embodiments, a bias circuit may include a successive-approximation-register-analog-to-digital converter (SAR-ADC) based settling loop configured to perform a fast settling process for a heavily loaded bias node. The SAR-ADC based loop performs a SAR-ADC process that includes measuring a reference signal to determine a number of cells in a capacitor array that are involved in a charge sharing process while simultaneously completing the settling process for the bias node.

Abstract: Aspects of the present disclosure include a frequency-to-current (F2I) circuit and systems, methods, devices, and other circuits related thereto. The F2I circuit is implemented with a delta-modulator-based control loop to settle and maintain an operating point on a bias node. The control loop provides an integral of an output of a comparator, and the comparator compares it to a self-built voltage reference. Upon powering on the circuit, an integrator in the control loop starts to integrate the charge on both a bias voltage and an internal voltage to provide a settling process for the internal voltage to approximate the reference voltage and for the bias voltage to approximate a predetermined operating point of the bias node. After the circuit has settled, the comparator's output charge toggles and the internal voltage and bias voltage become sawtooth-like waveforms at the reference voltage and operating points, respectively.