US 10,848,171 B1Granted

Hybrid multiplying capacitive digital-to-analog converter (MC-DAC) based loop regulation

AssigneeXilinx, Inc.

InventorsDeclan Carey, Frantz Stephane Florent Ngankem Ngankem, Pedro W. Neto, Ronan Casey

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Abstract

Apparatus and associated methods relate to providing a regulation loop using a digital representation of a loop error signal along with a flexible multiplying capacitive digital-to-analog converter (MC-DAC) circuit to control one or more power switches (e.g., transistors) delivering required power (including voltage and/or current) to a load circuit. In an illustrative example, the MC-DAC circuit may include a digital-to-analog converter (DAC) configured to selectively couple to two different reference voltages in response to switch control signals generated by a digital filter. A capacitive level shifter may be coupled to the output of the DAC. A re-sampling circuit may be coupled to the output of the capacitive level shifter to generate a gate control signal to control the one or more power switches. The regulation loop may advantageously generate the gate control signal using a substantially reduced die area.

Claims20

Dependent claims

A circuit comprising:

a digital-to-analog converter (DAC) having an input capacitance array and a first capacitor, the first capacitor is coupled between an output node of the DAC and a predetermined voltage node, wherein one or more capacitors in the input capacitance array are selectively coupled to receive a first programmable reference voltage signal and a second programmable reference voltage signal to generate an intermediate voltage signal to charge the first capacitor in response to a number of switch control signals derived from an n-bit digital filter;
a capacitive level shifter having a first terminal and a second terminal, wherein the first terminal is selectively coupled to a third programmable reference voltage, and the second terminal is selectively coupled to a fourth programmable reference voltage, wherein the second terminal is further selectively coupled to the DAC to receive the intermediate voltage signal;
and,
a re-sampling circuit selectively coupled to the first terminal of the capacitive level shifter to generate a settled voltage signal by refreshing the DAC and the capacitive level shifter.

1 more element

A system comprising:

a comparator configured to receive a signal and a first predetermined reference value to generate a comparison result;
a digital filter coupled to an output of the comparator to receive the comparison result;
and,
an analog voltage generation circuit coupled to an output of the digital filter to generate a first analog signal, wherein the analog voltage generation circuit comprises:
(a) a digital-to-analog converter (DAC) having an input capacitance array and a first capacitor, the first capacitor is coupled between an output node of the DAC and a predetermined voltage node, wherein one or more capacitors in the input capacitance array are selectively coupled to receive a first programmable reference voltage signal and a second programmable reference voltage signal to generate an intermediate voltage signal to charge the first capacitor in response to a number of switch control signals derived from the digital filter;
(b) a capacitive level shifter having a first terminal and a second terminal, wherein the first terminal is selectively coupled to a third programmable reference voltage, and the second terminal is selectively coupled to a fourth programmable reference voltage, wherein the second terminal is further selectively coupled to the DAC to receive the intermediate voltage signal;
and,
(c) a re-sampling circuit selectively coupled to the first terminal of the capacitive level shifter to generate a settled voltage signal by refreshing the DAC and the capacitive level shifter.

5 more elements

Dependencies are inferred from the claim text.