A small spike pulse excitation source circuit and a test method thereof

Abstract

This invention provides an excitation source circuit for small spike pulses and a testing method thereof. The circuit includes an excitation source circuit and an auxiliary protection circuit. The excitation source circuit includes operational amplifiers N1 and N2, a reference source V1, and a resistor R3. The reference source V1 and resistor R3 are used to control the output current of the excitation source circuit. The auxiliary protection circuit includes a Zener diode V2, a parallel protection resistor R1, a series protection resistor R2, and a parallel capacitor C1. The Zener diode V2 is used to clamp the voltage. The parallel capacitor C1 and the series protection resistor R2 are used for filtering, and together with the Zener diode V2 and the parallel protection resistor R1, prevent the generation of rising edge spike pulses exceeding 0.5V on the tested object. The series protection resistor R2 is used to raise the measurement voltage. Through the above circuit, the problem of spike pulse damage to the interface circuit during testing is solved, and the tested interface circuit is protected in a simple and reliable way.

Description

Technical Field

[0001] This invention relates to the field of excitation source circuit technology, and in particular to an excitation source circuit for small spike pulses and its testing method. Background Technology

[0002] After equipment manufacturing is complete, it is necessary to test the continuity and insulation between points on the interface of the device under test (DUT). This requires applying an excitation source between the points to complete the continuity and insulation test. While traditional excitation source test circuits meet the functional requirements, the instantaneous high voltage of these circuits causes voltage spikes on the rising edge of the excitation source when applied to the interface circuit of the DUT. These spikes can reach voltages of up to tens of volts. Since some types of electronic components are voltage-sensitive, applying voltages exceeding 6 volts may damage the interface circuit or even burn out the DUT. Therefore, some applications require excitation source circuits with small voltage spikes for measurement.

[0003] Therefore, solving the problem of spike pulse damage to interface circuits during testing and protecting the interface circuit under test in a simple and reliable way has become one of the existing technical problems that urgently need to be solved. Summary of the Invention

[0004] This invention provides an excitation source circuit for small spike pulses and a testing method thereof, which solves the problem of spike pulses damaging interface circuits during testing, and protects the interface circuit under test in a simple and reliable way.

[0005] In a first aspect, a small spike pulse excitation source circuit is provided, comprising: an excitation source circuit and an auxiliary protection circuit; wherein, The excitation source circuit includes: operational amplifier N1, operational amplifier N2, reference source V1, and resistor R3; the reference source V1 and resistor R3 are used to control the output current of the excitation source circuit. The auxiliary protection circuit includes: a Zener diode V2, a parallel protection resistor R1, a series protection resistor R2, and a parallel capacitor C1; the Zener diode V2 is used to clamp the voltage; the parallel capacitor C1 and the series protection resistor R2 are used for filtering, and together with the Zener diode V2 and the parallel protection resistor R1, prevent the generation of rising edge spike pulses exceeding 0.5V on the measured object; the series protection resistor R2 is used to raise the measurement voltage.

[0006] In one embodiment, the excitation source circuit of the small spike pulse is connected to the object under test via an adapter cable.

[0007] In one embodiment, the excitation source circuit employs a microampere-level high-performance constant current source.

[0008] In one embodiment, the operational amplifier N1 is an instrumentation amplifier INA118; the operational amplifier N2 is a high-sensitivity operational amplifier OPA602; the reference source V1 is selected as ADR441 when the actual voltage regulation requirement is 2.5V, and as ADR445 when the actual voltage regulation requirement is 5V.

[0009] In one embodiment, the resistor R3 is a precision resistor. When the resistance of R3 is 1kΩ, the excitation source circuit outputs 3.3mA, and the resistance range of the object under test can be measured from 0 to 1kΩ; when the resistance of R3 is 10kΩ, the excitation source circuit outputs 333uA, and the resistance range of the object under test can be measured from 1kΩ to 10kΩ; when the resistance of R3 is 100kΩ, the excitation source circuit outputs 33.3uA, and the resistance range of the object under test can be measured from 10kΩ to ∞.

[0010] In one embodiment, the Zener diode V2 is selected as ADR550 when the actual clamping voltage needs to be 5V, and as ADR530 when the actual clamping voltage needs to be 3V.

[0011] In one embodiment, the capacitance of the parallel capacitor C1 is 0.1uF.

[0012] Secondly, a test method for a small spike pulse excitation source circuit is provided, the method being applied to the aforementioned excitation source circuit, comprising: The test object is connected to the excitation source circuit of the small spike pulse via a conversion cable. The excitation source circuit of the small spike pulse includes an excitation source circuit and an auxiliary protection circuit. The excitation source circuit applies excitation to the test object in the form of current, and the auxiliary protection circuit controls the voltage amplitude. The on-resistance of the object under test is tested based on the excitation source circuit of the small spike pulse to obtain the voltage value on the object under test. Based on the oscilloscope display connected in parallel to the object under test, the rising edge spike pulse is acquired. The size of the rising edge spike pulse is controlled by controlling the Zener diode V2, the parallel protection resistor R1, the series protection resistor R2, and the parallel capacitor C1.

[0013] In one embodiment, the Zener diode V2 and the parallel protection resistor R1 are used to clamp the voltage to the required set value when the object under test is highly resistive; the series protection resistor R2 and the parallel capacitor C1 are used for filtering, and together with the Zener diode V2 and the parallel protection resistor R1, the rising edge spike pulse exceeding 0.5V will not be generated on the object under test.

[0014] In one embodiment, the series protection resistor R2 raises the measurement voltage by connecting it in series, thus avoiding the measurement results from being affected by noise.

[0015] This invention provides an excitation source circuit for small spike pulses and a testing method thereof. The circuit includes an excitation source circuit and an auxiliary protection circuit. The excitation source circuit includes operational amplifiers N1 and N2, a reference source V1, and a resistor R3. The reference source V1 and resistor R3 are used to control the output current of the excitation source circuit. The auxiliary protection circuit includes a Zener diode V2, a parallel protection resistor R1, a series protection resistor R2, and a parallel capacitor C1. The Zener diode V2 is used to clamp the voltage. The parallel capacitor C1 and the series protection resistor R2 are used for filtering, and together with the Zener diode V2 and the parallel protection resistor R1, prevent the generation of rising edge spike pulses exceeding 0.5V on the tested object. The series protection resistor R2 is used to raise the measurement voltage. Through the above circuit, the problem of spike pulse damage to the interface circuit during testing is solved, and the tested interface circuit is protected in a simple and reliable way.

[0016] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of the test model of the excitation source circuit for the small spike pulse according to an embodiment of the present invention; Figure labels: 1. Excitation source circuit for small spike pulse; 2. Adapter cable; 3. Object under test; Figure 2 This is a schematic diagram of the excitation source circuit according to an embodiment of the present invention; Figure 3 This is a schematic diagram of an auxiliary protection circuit according to an embodiment of the present invention; Figure 4 This is a flowchart of a test method for the excitation source circuit of a small spike pulse according to an embodiment of the present invention. Detailed Implementation

[0018] To address the problem of spike pulses damaging interface circuits during testing and to protect the interface circuit under test in a simple and reliable manner, a small spike pulse excitation source circuit and its testing method are provided.

[0019] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] like Figures 1-3 As shown, the embodiment provides an excitation source circuit for a small spike pulse, including: an excitation source circuit and an auxiliary protection circuit; wherein, The excitation source circuit includes: operational amplifier N1, operational amplifier N2, reference source V1, and resistor R3; the reference source V1 and resistor R3 are used to control the output current of the excitation source circuit. The auxiliary protection circuit includes: a Zener diode V2, a parallel protection resistor R1, a series protection resistor R2, and a parallel capacitor C1; the Zener diode V2 is used to clamp the voltage; the parallel capacitor C1 and the series protection resistor R2 are used for filtering, and together with the Zener diode V2 and the parallel protection resistor R1, prevent the generation of rising edge spike pulses exceeding 0.5V on the measured object; the series protection resistor R2 is used to raise the measurement voltage.

[0021] In one embodiment, the excitation source circuit of the small spike pulse is connected to the object under test via an adapter cable.

[0022] In one embodiment, the excitation source circuit employs a microampere-level high-performance constant current source. This excitation source circuit exhibits excellent performance characteristics such as high input impedance, extremely low output impedance, and a high common-mode rejection ratio.

[0023] In one embodiment, the operational amplifier N1 is selected as an instrumentation amplifier INA118; the operational amplifier N2 is selected as a high-sensitivity operational amplifier OPA602; the reference source V1 is selected as ADR441 when the actual voltage regulation requirement is 2.5V, and as ADR445 when the actual voltage regulation requirement is 5V. The specific value can be adjusted according to the actual voltage regulation requirement, and together with R3, it controls the output current of the excitation source circuit.

[0024] In one embodiment, the resistor R3 is a precision resistor that directly controls the current output of the excitation source circuit. When the resistance of R3 is 1kΩ, the excitation source circuit outputs 3.3mA, and the resistance range of the object under test can be measured from 0 to 1kΩ; when the resistance of R3 is 10kΩ, the excitation source circuit outputs 333uA, and the resistance range of the object under test can be measured from 1kΩ to 10kΩ; when the resistance of R3 is 100kΩ, the excitation source circuit outputs 33.3uA, and the resistance range of the object under test can be measured from 10kΩ to ∞.

[0025] In one embodiment, the Zener diode V2 is selected as ADR550 when the actual clamping voltage needs to be 5V, and as ADR530 when the actual clamping voltage needs to be 3V. The specific value can be adjusted according to the actual clamping voltage requirement, so as to clamp the voltage to the set voltage value. R1 and R2 are parallel protection resistors and series protection resistors, respectively. When the clamping voltage needs to be 5V, the resistance values ​​are 70kΩ and 20Ω, respectively, which can be adjusted according to actual needs. The parallel voltage can be controlled by changing the value of the parallel resistor R1, and the series current can be controlled by changing the value of the parallel resistor R2.

[0026] In one embodiment, the capacitance of the parallel capacitor C1 is 0.1uF.

[0027] This embodiment provides an excitation source circuit for small spike pulses, including: an excitation source circuit and an auxiliary protection circuit; wherein, the excitation source circuit includes: operational amplifier N1, operational amplifier N2, reference source V1, and resistor R3; the reference source V1 and resistor R3 are used to control the output current of the excitation source circuit; the auxiliary protection circuit includes: Zener diode V2, parallel protection resistor R1, series protection resistor R2, and parallel capacitor C1; the Zener diode V2 is used to clamp the voltage; the parallel capacitor C1 and series protection resistor R2 are used for filtering, and together with the Zener diode V2 and parallel protection resistor R1, prevent the generation of rising edge spike pulses exceeding 0.5V on the measured object; the series protection resistor R2 is used to raise the measurement voltage.

[0028] The excitation source circuit applies current to the interface under test; the auxiliary protection circuit controls the voltage amplitude to reduce voltage spikes. The advantage of this invention lies in the coordinated design of the excitation source circuit and the auxiliary circuit, forming a novel excitation source design circuit. This circuit features low-rise spikes, is simple and reliable, and reduces spikes from tens of volts to 0.5 volts compared to existing excitation source test circuits, thus achieving the goal of protecting the interface under test.

[0029] Based on the same technical concept, this application embodiment also provides a test method for the excitation source circuit of a small spike pulse. Since the method is applied to the excitation source circuit of the small spike pulse, the implementation of the method can refer to the implementation of the excitation source circuit of the small spike pulse, and the repeated parts will not be described again.

[0030] like Figure 4 As shown, the embodiment provides a test method for the excitation source circuit of a small spike pulse, and the specific implementation steps include: S41. The test object is connected to the excitation source circuit of the small spike pulse via a conversion cable. The excitation source circuit of the small spike pulse includes an excitation source circuit and an auxiliary protection circuit. The excitation source circuit applies excitation to the test object in the form of current, and the auxiliary protection circuit controls the voltage amplitude.

[0031] S42. Perform a continuity resistance test on the object under test based on the excitation source circuit of the small spike pulse, and obtain the voltage value on the object under test.

[0032] In practice, the excitation source circuit applies a current excitation of 33.3uA-3.3mA to the object under test, and the voltage amplitude is controlled to 5V by the auxiliary protection circuit. The voltage control result can be observed using an oscilloscope. Rx is the resistance of the object under test, and the oscilloscope measures the voltage across the object. For continuity resistance testing, the voltage Vx across the object under test can be obtained. When the excitation source circuit outputs 3.3mA, the resistance range of Rx can be measured from 0 to 1kΩ; when it outputs 333uA, the resistance range is 1kΩ to 10kΩ; and when it outputs 33.3uA, the resistance range is 10kΩ to infinity. This step-by-step measurement principle improves measurement accuracy.

[0033] S43. Based on the oscilloscope display connected in parallel to the object under test, obtain the rising edge spike pulse, and control the magnitude of the rising edge spike pulse by controlling the Zener diode V2, the parallel protection resistor R1, the series protection resistor R2 and the parallel capacitor C1.

[0034] In practice, observe the rising edge spike pulse on the oscilloscope. By controlling the Zener diode V2, resistor R1, resistor R2, and capacitor C1, the size of the rising edge spike pulse can be effectively controlled.

[0035] When the excitation source circuit applies current to the object under test, for high-resistivity objects, the circuit's Zener diode V2 (ADR550) and parallel protection resistor R1 can clamp the voltage to 5V. Through the filtering effect of the parallel capacitor C1 and the series protection resistor R2, together with the Zener diode V2 and the parallel protection resistor R1, no rising edge spike pulse exceeding 0.5V is generated on the object under test, while avoiding the risk of the constant current source being open-circuited. For low-resistivity objects, the series protection resistor R2 can raise the measurement voltage through series connection to avoid being affected by noise.

[0036] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0037] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A small spike pulse excitation source circuit, characterized in that, include: Excitation source circuit and auxiliary protection circuit; among which, The excitation source circuit includes: operational amplifier N1, operational amplifier N2, reference source V1, and resistor R3; the reference source V1 and resistor R3 are used to control the output current of the excitation source circuit. The auxiliary protection circuit includes: a Zener diode V2, a parallel protection resistor R1, a series protection resistor R2, and a parallel capacitor C1; the Zener diode V2 is used to clamp the voltage; the parallel capacitor C1 and the series protection resistor R2 are used for filtering, and together with the Zener diode V2 and the parallel protection resistor R1, prevent the generation of rising edge spike pulses exceeding 0.5V on the measured object; the series protection resistor R2 is used to raise the measurement voltage.

2. The excitation source circuit for the small spike pulse according to claim 1, characterized in that, The excitation source circuit of the small spike pulse is connected to the object under test via an adapter cable.

3. The excitation source circuit for the small spike pulse according to claim 2, characterized in that, The excitation source circuit uses a microampere-level high-performance constant current source.

4. The excitation source circuit for the small spike pulse according to claim 3, characterized in that, The operational amplifier N1 is an instrumentation amplifier INA118; the operational amplifier N2 is a high-sensitivity operational amplifier OPA602; the reference source V1 is selected as ADR441 when the actual voltage regulation requirement is 2.5V, and as ADR445 when the actual voltage regulation requirement is 5V.

5. The excitation source circuit for the small spike pulse according to claim 4, characterized in that, The resistor R3 is a precision resistor. When the resistance of R3 is 1kΩ, the excitation source circuit outputs 3.3mA, and the resistance range of the object under test can be measured from 0 to 1kΩ; when the resistance of R3 is 10kΩ, the excitation source circuit outputs 333uA, and the resistance range of the object under test can be measured from 1kΩ to 10kΩ; when the resistance of R3 is 100kΩ, the excitation source circuit outputs 33.3uA, and the resistance range of the object under test can be measured from 10kΩ to ∞.

6. The excitation source circuit for the small spike pulse according to claim 5, characterized in that, The Zener diode V2 is selected as ADR550 when the actual clamping voltage needs to be 5V, and as ADR530 when the actual clamping voltage needs to be 3V.

7. The excitation source circuit for the small spike pulse according to claim 6, characterized in that, The capacitance of the parallel capacitor C1 is 0.1uF.

8. A test method for a small spike pulse excitation source circuit, the method being applied to the small spike pulse excitation source circuits described in 1-7, characterized in that, include: The test object is connected to the excitation source circuit of the small spike pulse via a conversion cable. The excitation source circuit of the small spike pulse includes an excitation source circuit and an auxiliary protection circuit. The excitation source circuit applies excitation to the test object in the form of current, and the auxiliary protection circuit controls the voltage amplitude. The on-resistance of the object under test is tested based on the excitation source circuit of the small spike pulse to obtain the voltage value on the object under test. Based on the oscilloscope display connected in parallel to the object under test, the rising edge spike pulse is acquired. The size of the rising edge spike pulse is controlled by controlling the Zener diode V2, the parallel protection resistor R1, the series protection resistor R2, and the parallel capacitor C1.

9. The method according to claim 8, characterized in that, The Zener diode V2 and the parallel protection resistor R1 are used to clamp the voltage to the required set value when the object under test is highly resistive; the series protection resistor R2 and the parallel capacitor C1 are used for filtering, and together with the Zener diode V2 and the parallel protection resistor R1, the rising edge spike pulse exceeding 0.5V will not be generated on the object under test.

10. The method according to claim 9, characterized in that, The series protection resistor R2 raises the measurement voltage by connecting it in series, thus avoiding the measurement results being affected by noise.

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