Enhanced switched capacitor filter (SCF) compensation in DC-DC converters

Patent metadata

Field	Value
Publication number	US-10008928-B2
Application number	US-201614989619-A
Country	US
Kind code	B2
Filing date	Jan 6, 2016
Priority date	Aug 14, 2015
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A system, DC-DC converter, and compensation method and circuit for a DC-DC converter are disclosed. For example, a compensation circuit for a DC-DC converter is disclosed. The compensation circuit includes an integrator circuit configured to receive and integrate a first voltage signal, a differential difference amplifier circuit coupled to the integrator circuit and configured to generate a first filter transfer function associated with the integrated first voltage signal, and a switched capacitor filter circuit coupled to the differential difference amplifier circuit and configured to generate a second filter transfer function, wherein the differential difference amplifier is further configured to output a second voltage signal responsive to the first filter transfer function and the second filter transfer function. In one implementation, the compensation circuit is a type-III switched capacitor filter (SCF) compensation circuit.

First claim

What is claimed is:

1. A compensation circuit, comprising:
an integrator circuit configured to receive and integrate a first voltage signal;
a differential difference amplifier circuit coupled to the integrator circuit and configured to generate a first filter transfer function associated with the integrated first voltage signal; and
a switched capacitor filter circuit coupled to the differential difference amplifier circuit and configured to generate a second filter transfer function, wherein the differential difference amplifier is further configured to output a second voltage signal responsive to the first filter transfer function and the second filter transfer function.

2. The compensation circuit of claim 1 , wherein the compensation circuit comprises a type-III switched capacitor filter compensation circuit for a DC-DC converter.

3. The compensation circuit of claim 1 , wherein the integrator circuit comprises a continuous-time integrator front-end circuit.

4. The compensation circuit of claim 1 , wherein the integrator circuit comprises a switched capacitor integrator circuit.

5. The compensation circuit of claim 1 , wherein the switched capacitor filter circuit comprises a type-III switched capacitor filter circuit.

6. The compensation circuit of claim 1 , wherein the differential difference amplifier includes a first input configured to receive the integrated first voltage signal, a second input configured to receive the first voltage signal, a third input configured to receive a common-mode voltage signal, and a fourth input configured to receive a filtered voltage signal associated with the common-mode voltage signal.

7. The compensation circuit of claim 1 , wherein the differential difference amplifier circuit includes two pairs of differential inputs.

8. The compensation circuit of claim 1 , wherein the differential difference amplifier circuit is configured to realize a type-III filter transfer function that enables an implicit cascading of transfer functions received at two pairs of differential inputs of the differential difference amplifier.

9. A DC-DC voltage converter, comprising:
a power circuit; and
a controller circuit coupled to the power circuit, the controller circuit including a compensation circuit comprising:
an integrator circuit configured to receive an output voltage from the DC-DC voltage converter and integrate the output voltage signal;
a differential difference amplifier circuit coupled to the integrator circuit and configured to generate a first filter transfer function associated with the integrated output voltage signal; and
a switched capacitor filter circuit coupled to the differential difference amplifier circuit and configured to generate a second filter transfer function, wherein the differential difference amplifier is further configured to generate a compensation voltage signal for the DC-DC voltage converter responsive to the first filter transfer function and the second filter transfer function.

10. The DC-DC voltage converter of claim 9 , wherein the DC-DC voltage converter comprises a switched mode PWM voltage converter.

11. The DC-DC voltage converter of claim 9 , wherein the DC-DC voltage converter comprises a buck converter or step-down voltage converter.

12. An electronic system, comprising:
a digital processor;
a peripheral subsystem coupled to the digital processor; and
a power subsystem coupled to the digital processor and circuit components of the peripheral subsystem and configured to generate an output voltage to power the digital processor and the circuit components of the peripheral subsystem, wherein the power subsystem includes a DC-DC converter configured to regulate the output voltage of the power subsystem, and the DC-DC converter includes a switched capacitor filter compensation circuit comprising:
an integrator circuit configured to receive and integrate a difference of the output voltage and a reference voltage;
a differential difference amplifier circuit coupled to an output of the integrator circuit and configured to generate a first filter transfer function; and
a switched capacitor filter circuit coupled to the differential difference amplifier circuit and configured to generate a second filter transfer function, wherein the differential difference amplifier is further configured to output a compensation voltage signal for the DC-DC converter responsive to the first filter transfer function and the second filter transfer function.

13. The electronic system of claim 12 , wherein the DC-DC converter comprises a buck converter.

14. The electronic system of claim 12 , wherein the switched capacitor filter compensation circuit and the power subsystem are formed on one or more integrated circuits, wafers, chips or dies.

Assignees

• Intersil Americas LLC

Inventors

• Bawa Gaurav

Classifications

• H02M2001/0025

  Electricity · mapped topic

• H02M3/156 Primary

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H02M2003/1566

  Electricity · mapped topic

• H02M3/1566

  with means for compensating against rapid load changes, e.g. with auxiliary current source, with dual mode control or with inductance variation · CPC title

• H02M1/0025

  Arrangements for modifying reference values, feedback values or error values in the control loop of a converter · CPC title