SYSTEMS, DEVICES, AND METHODS FOR MEASURING DIRECT CURRENT/LOW FREQUENCY SIGNAL COMPONENTS

• US 20200132731A1
• Filed: 07/13/2018
• Published: 04/30/2020
• Est. Priority Date: 07/14/2017
• Status: Active Grant

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Mende, Michael J.
• Granted Patent: US 11,635,452 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 1/06766 Input circuits therefor
• CPC Class Codes: G01R 1/06772 High frequency probes
• CPC Class Codes: G01R 15/125 for digital multimeters
• CPC Class Codes: G01R 19/0015 separating AC and DC

Abstract

A test and measurement probe system (100,104), including an input (106) to receive an input signal, the input signal including a low frequency (LF) and/or direct current (DC) component and an alternating current (AC) component, an extractor circuit (110), such as an AC coupling circuit or a LF and/or DC rejection circuit, configured to receive the input signal and to separate the AC component and the LF and/or DC component from the input signal, a first output (118) to output the alternating current component to the test and measurement instrument, and a second output to output the direct current component to the test and measurement instrument. In some embodiments, the LF and/or DC component is digitized prior to being output by the second output.

Claims

1. A test and measurement probe system, comprising:

an input to receive an input signal, the input signal including a direct current (DC) component and an alternating current (AC) component;

an extractor circuit configured to receive the input signal and to separate the AC component and the DC component from the input signal;

a first output to output the AC component to the test and measurement instrument; and

a second output to output the DC component to the test and measurement instrument.

2. The test and measurement probe system of claim 1, further comprising an analog-to-digital converter to receive the DC component and convert the DC component to a digitized DC component, wherein the second output is configured to output the digitized DC component.

3. The test and measurement probe system of claim 1, further comprising a buffer, the buffer configured to receive the DC component and output the DC component through the second output.

4. The test and measurement probe system of claim 1, wherein the extractor circuit is a DC rejection circuit configured to receive the input signal and output the DC component.

5. The test and measurement probe system of claim 4, wherein the DC component is a feedback signal which is fed back to the input signal to separate the AC component.

6. The test and measurement probe system of claim 1, wherein the extractor circuit includes an AC coupling circuit.

7. The test and measurement probe system of claim 1, wherein the input signal includes a differential signal.

8. The test and measurement probe system of claim 1, wherein the first output is connected to a first channel of the test and measurement instrument and the second output is connected to a second channel of the test and measurement instrument different from the first channel.

9. The test and measurement probe system of claim 1, further comprising an isolation device to receive the DC component and output an isolated DC component to the second output.

10. The test and measurement probe system of claim 1, wherein the second output is connected to a digital multimeter input of the test and measurement instrument.

11. A method, comprising:

receiving an input signal, the input signal including a low frequency (LF) component and an alternating current (AC) component;

extracting the LF component from the input signal;

extracting the AC component from the input signal;

transmitting the AC component to a test and measurement instrument through a first output; and

transmitting the LF component to the test and measurement instrument through a second output.

12. The method of claim 11, further comprising converting the LF component to a digitized LF component, wherein transmitting the LF component includes transmitting the digitized LF component.

13. The method of claim 11, further comprising transmitting the LF component to a digital multimeter input of the test and measurement instrument.

14. The method of claim 11, further comprising buffering the LF component to delay the transmission of the LF component through the second output.

15. The method of claim 11, wherein extracting the LF component from the input signal and extracting the AC component from the input signal includes extracting the LF component and the AC component through a direct current rejection circuit by adding the LF component to the input signal to extract the AC component.

16. The method of claim 11, wherein extracting the LF component from the input signal and extracting the AC component from the input signal includes extracting the LF component and the AC component through an AC coupling circuit.

17. The method of claim 11, wherein the second output is a communication interface.

18. The method of claim 11, wherein transmitting the AC component to the test and measurement instrument through the first output includes transmitting the AC component to a first channel of a test and measurement instrument;

and

wherein transmitting the LF component to the test and measurement instrument through a second output includes transmitting the LF component to a second channel of the test and measurement instrument different from the first channel.

19. The method of claim 11, further comprising isolating the LF component prior to transmitting the LF component.

20. The method of claim 11, further comprising displaying the AC component and the LF component of the input signal simultaneously.