Drive sense circuit with transient suppression

Patent metadata

Field	Value
Publication number	US-12449462-B2
Application number	US-202117249260-A
Country	US
Kind code	B2
Filing date	Feb 25, 2021
Priority date	Nov 19, 2018
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A method includes providing, by a signal source circuit of a sensing circuit, a signal to a sensor via a conductor. When the sensor is exposed to a condition and is receiving the signal, an electrical characteristic of the sensor affects the signal. The signal includes at least one of: a direct current (DC) component and an oscillating component. When the sensing circuit is in a noisy environment, transient noise couples with the signal to produce a noisy signal. The method further includes comparing, by a transient circuit of the sensing circuit, the noisy signal with a representation of the noisy signal. When the noisy signal compares unfavorably with the representation of the noisy signal, supplying, by the transient circuit, a compensation signal to the conductor. A level of the compensation signal corresponds to a level at which the noisy signal compares unfavorably with the representation of the noisy signal.

First claim

What is claimed is:

1. A method comprises:
providing, by a signal source circuit of a sensing circuit, a signal to a sensor via a conductor, wherein, when the sensor is exposed to a condition and is receiving the signal, an electrical characteristic of the sensor affects the signal, wherein the signal includes at least one of: a direct current (DC) component and an oscillating component, wherein, when the sensing circuit is in a noisy environment, transient noise couples with the signal to produce a noisy signal;
comparing, by a transient circuit of the sensing circuit, the noisy signal with a representation of the noisy signal; and
when the noisy signal compares unfavorably with the representation of the noisy signal, supplying, by the transient circuit, a compensation signal to the conductor, wherein a level of the compensation signal corresponds to a level at which the noisy signal compares unfavorably with the representation of the noisy signal.

2. The method of claim 1 further comprises:
when the noisy signal compares unfavorably with the representation of the noisy signal in a first manner, sourcing, by the transient circuit, a first current on the conductor, wherein a level of the first current corresponds to a first level at which the noisy signal compares unfavorably with the representation of the noisy signal; and
when the noisy signal compares unfavorably with the representation of the noisy signal in a second manner, sinking, by the transient circuit, a second current from the conductor, wherein a level of the second current corresponds to a second level at which the noisy signal compares unfavorably with the representation of the noisy signal.

3. The method of claim 1 further comprises:
sourcing, by a power source circuit of the signal source circuit, at least one of a voltage and a current to the sensor to produce the signal or to produce a power signal as the signal;
detecting, by a change detection circuit of the signal source circuit, the effects on the signal as a result of the electrical characteristic;
generating, by the change detection circuit, a signal that is representative of change to the signal based on the detected effect on the signal; and
generating, by a regulation circuit of the signal source circuit, a regulation signal to at least one of, regulate the DC component to a desired DC level and regulate the oscillating component to a desired oscillating level based on the signal that is representative of the change to the signal.

4. The method of claim 1 further comprises:
delaying, by a delay circuit of the transient circuit, the noisy signal to produce the representation of the noisy signal;
comparing, by an operational amplifier of the transient circuit, the noisy signal with the representation of the noisy signal; and
supplying, by a dependent supply source of the transient circuit, the compensation signal.

5. The method of claim 4 further comprises:
receiving, by an integration circuit of the delay circuit, as an input the noisy signal and output the representation of the noisy signal; and
receiving, by a low pass filter circuit of the delay circuit, as an input the noisy signal and output the representation of the noisy signal.

6. The method of claim 4 , wherein the dependent supply source includes one of:
a dependent current source; and
a dependent voltage source.

7. The method of claim 1 further comprises:
producing, by an integrator circuit of the transient circuit, the representation of the noisy signal;
comparing, by an operational amplifier of the transient circuit, the noisy signal with the representation of the noisy signal; and
supplying, by a current source of the transient circuit, the current to the conductor.

8. The method of claim 1 further comprises:
producing, by a low pass filter circuit of the transient circuit, the representation of the noisy signal;
comparing, by an operational amplifier of the transient circuit, the noisy signal with the representation of the noisy signal; and
supplying, by a current source of the transient circuit, the current to the conductor.

9. The method of claim 1 further comprises:
comparing, by a first operational amplifier of the transient circuit the noisy signal with a first representation of the noisy signal;
sourcing, by a first current source of the transient circuit, the current to the conductor;
comparing, by a second operational amplifier of the transient circuit, the noisy signal with a second representation of the noisy signal; and
sinking, by a second current source of the transient circuit, the current to the conductor.

10. A method comprises:
comparing, by a comparator of a sensing circuit, a regulated source signal and a reference source signal to produce a comparison signal wherein when the sensing circuit is in a noisy environment, noise couples to the regulated source signal to produce a noisy signal;
converting, by an analog to digital converter (ADC) of the sensing circuit, the comparison signal into a digital signal;
converting, by a digital to analog converter (DAC) of the sensing circuit, the digital signal into an analog regulated signal;
producing, by a dependent current source of the sensing circuit, the regulated source signal based on the analog regulation signal, wherein the dependent current source is sourced by a direct current (DC) input voltage; and
comparing, by a transient circuit of the sensing circuit, the noisy signal with a representation of the noisy signal; and
when the noisy signal compares unfavorably with the representation of the noisy signal, supplying by the transient circuit, a compensation signal to the DAC, wherein a level of the compensation signal corresponds to a level at which the noisy signal compares unfavorably with the representation of the noisy signal.

11. The method of claim 10 , wherein the sensing circuit further comprises:
an alternate current (AC) coupling circuit operably coupled to the transient circuit and an output of the DAC.

12. The method of claim 10 further comprises:
when the noisy signal compares unfavorably with the representation of the noisy signal in a first manner, sourcing, by the transient circuit, a first current to the DAC, wherein a level of the first current corresponds to a first level at which the noisy signal compares unfavorably with the representation of the noisy signal; and
when the noisy signal compares unfavorably with the representation of the noisy signal in a second manner, sinking, by the transient circuit, a second current from the DAC, wherein a level of the second current corresponds to a second level at which the noisy signal compares unfavorably with the representation of the noisy signal.

13. The method of claim 10 further comprises:
delaying, by a delay circuit of the transient circuit, the noisy signal to produce the representation of the noisy signal;
comparing, by an operational amplifier of the transient circuit, the noisy signal with the representation of the noisy signal; and
supplying, by a dependent supply source of the transient circuit, the compensation signal.

14. The method of claim 13 comprises one of:
receiving, by an integration circuit of the transient circuit, as an input the noisy signal and output the representation of the noisy signal; and
receiving, by a low pass filter circuit of the transient circuit, as an input the noisy signal and output the representation of the noisy signal.

15. The method of claim 13 , wherein the dependent supply source includes one of:
a dependent current source; and
a dependent voltage source.

Assignees

• Sigmasense Llc

Inventors

• Huynh Phuong
• Gray Patrick Troy

Classifications

• H03K5/1252

  Suppression or limitation of noise or interference (specially adapted for transmission systems H04B15/00, H04L25/08) · CPC title

• H03M1/12

  Analogue/digital converters ({H03M1/001 – } H03M1/10 take precedence) · CPC title

• H03F2203/45116

  Feedback coupled to the input of the differential amplifier · CPC title

• H03F2200/129

  there being a feedback over the complete amplifier · CPC title

• H03K2005/00078

  Fixed delay · CPC title