# US 2019/0379367 A1 · Parameter-independent ramp signal generation

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2019/0379367 A1
- Document ID: US20190379367A1
- Status: Published application
- Kind: A1
- Application number: 16/431,320
- Filed: 2019-06-04
- Published: 2019-12-12
- Earliest claimed: 2018-06-11
- Assignees: Cirrus Logic International Semiconductor Ltd.
- Applicants: Cirrus Logic International Semiconductor Ltd.
- Inventors: Saraubh SINGH; Vamsikrishna PARUPALLI
- Web page: https://patentgrep.com/patent/US20190379367A1

## CPC

- H03K 4/50: in which a sawtooth voltage is produced across a capacitor
- H03H 11/04: Frequency selective two-port networks
- H03H 19/004: {Switched capacitor networks}
- H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M)
- H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P)

## Abstract

A system may include a ramp generation circuit for generating a ramp waveform and comprising a first passive circuit element having an impedance pertinent to generation of the ramp waveform and a control circuit comprising a second passive circuit element which is impedance-correlated to the first passive circuit element. The control circuit may be configured to use the second passive circuit element to generate a control signal for controlling the ramp generation circuit, such that a correlation between the first passive circuit element and the second passive circuit element substantially cancels physical variations of the first passive circuit element and the second passive circuit element and use a control signal clock for generating the control signal that is related to a ramp generation clock for generating the ramp waveform such that a magnitude of the ramp waveform remains substantially independent of frequency of operation.

## Claims

### Claim 1

A system comprising:
a ramp generation circuit for generating a ramp waveform and comprising a first passive circuit element having an impedance pertinent to generation of the ramp waveform; and
a control circuit comprising a second passive circuit element which is impedance-correlated to the first passive circuit element, wherein the control circuit is configured to:
use the second passive circuit element to generate a control signal for controlling the ramp generation circuit, such that a correlation between the first passive circuit element and the second passive circuit element substantially cancels physical variations of the first passive circuit element and the second passive circuit element; and
use a control signal clock for generating the control signal that is related to a ramp generation clock for generating the ramp waveform such that a magnitude of the ramp waveform remains substantially independent of frequency of operation.

### Claim 2 (depends on 1)

The system of claim 1, wherein the physical variations comprise at least a process variation.

### Claim 3 (depends on 1)

The system of claim 1, wherein the physical variations comprise at least a temperature variation.

### Claim 4 (depends on 1)

The system of claim 1, wherein the physical variations comprise at least a voltage supply variation.

### Claim 5 (depends on 1)

The system of claim 1, wherein the first passive circuit element comprises a first capacitor and the second passive circuit element is a second capacitor integral to a switched capacitor filter.

### Claim 6

A method comprising:
generating a ramp waveform with a ramp generation circuit, the ramp generation circuit comprising a first passive circuit element having an impedance pertinent to generation of the ramp waveform;
using a passive circuit element which is impedance-correlated to the first passive circuit element to generate a control signal for controlling the ramp generation circuit, such that a correlation between the first passive circuit element and the second passive circuit element substantially cancels physical variations of the first passive circuit element and the second passive circuit element; and
using a control signal clock for generating the control signal that is related to a ramp generation clock for generating the ramp waveform such that a magnitude of the ramp waveform remains substantially independent of frequency of operation.

### Claim 7 (depends on 6)

The method of claim 6, wherein the physical variations comprise at least a process variation.

### Claim 8 (depends on 6)

The method of claim 6, wherein the physical variations comprise at least a temperature variation.

### Claim 9 (depends on 6)

The method of claim 6, wherein the physical variations comprise at least a voltage supply variation.

### Claim 10 (depends on 6)

The method of claim 6, wherein the first passive circuit element comprises a first capacitor and the second passive circuit element is a second capacitor integral to a switched capacitor filter.