CN-122017313-A - Current sampling circuit and current sampling system

CN122017313ACN 122017313 ACN122017313 ACN 122017313ACN-122017313-A

Abstract

The application discloses a current sampling circuit and a current sampling system, and relates to the technical field of signal sampling, wherein the circuit comprises a sampling module, a control module and a sampling module, wherein the sampling module is respectively connected with equipment to be tested and a gating module; the system comprises a sampling module, a control module, a gating module and a target sampling unit, wherein the sampling module is used for sampling the current to be tested, the current information of the device to be tested is acquired, and a gating signal is transmitted to the gating module according to the current information. The sampling module is used for generating a corresponding potential difference signal according to the current to be detected and transmitting the potential difference signal to the control module through the gating module. Compared with the prior art, the application forms a continuous current path by at least two sampling units connected in series, and selects the target sampling unit for differential sampling based on the gating signal, thereby keeping current uninterrupted when switching the measuring range, and improving the system stability and the measuring precision.

Inventors

LUO GUOQING
TANG XINGWANG
LU JIANQIANG

Assignees

矽电半导体设备(深圳)股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260119

Claims (10)

1. The current sampling circuit is characterized by comprising a sampling module, a gating module and a control module, wherein at least two sampling units connected in series are arranged in the sampling module; the sampling module is respectively connected with the equipment to be tested and the gating module, and the control module is respectively connected with the equipment to be tested and the gating module; the control module is used for acquiring current information of the equipment to be tested and transmitting a gating signal to the gating module according to the current information; The gating module is used for selecting a target sampling unit from the sampling module to sample the current to be detected transmitted by the equipment to be detected according to the gating signal; the sampling module is used for generating a corresponding potential difference signal according to the current to be detected and transmitting the potential difference signal to the control module through the gating module.
2. The circuit of claim 1, wherein the sampling unit comprises: Sampling resistor, balance capacitor and bypass switch; the first end of the sampling resistor is connected with the first end of the balance capacitor, the first end of the bypass switch, the equipment to be tested and the gating module respectively, and the second end of the sampling resistor is connected with the second end of the balance capacitor, the second end of the bypass switch and the gating module respectively.
3. The circuit of claim 1, wherein the gating module comprises a potential acquisition unit and a channel selection unit; The input end of the potential acquisition unit is connected with the nodes of each sampling unit in the sampling module and is used for acquiring potential difference signals of each node; the channel selection unit is respectively connected with the output end of the potential acquisition unit and the control module; The channel selection unit is configured to select, from the potential difference signals of the nodes, a potential difference signal corresponding to the target sampling unit according to the strobe signal, and output the potential difference signal to the control module.
4. The circuit of claim 1, wherein the control module comprises an information acquisition unit, a signal generation unit, and a signal reception unit; the information acquisition unit is connected with the equipment to be detected and is used for acquiring current information of the equipment to be detected; The signal generating unit is connected with the information acquisition unit and is used for generating the gating signal according to the current information and transmitting the gating signal to the gating module; The signal receiving unit is connected with the gating module and is used for receiving the potential difference signal transmitted by the gating module.
5. The circuit of claim 3, wherein the potential acquisition unit comprises at least three voltage followers; the input end of the voltage follower is connected with the node of each sampling unit in the sampling module, and the output end of the voltage follower is connected with the channel selection unit.
6. The circuit of claim 1, further comprising a signal conditioning module; the signal conditioning module is connected between the gating module and the control module and is used for amplifying the potential difference signal.
7. The circuit of claim 6, further comprising a direction switching module; The direction switching is connected between the gating module and the signal conditioning module and is used for switching the polarity of the potential difference signal input to the signal conditioning module according to the flow direction of the current to be detected.
8. The circuit of claim 6, wherein the signal conditioning module comprises an instrumentation amplifier; The differential input end of the instrument amplifier is connected with the gating module and is used for receiving the potential difference signal; The output end of the instrument amplifier is connected with the control module and is used for transmitting the amplified potential difference signals to the control module.
9. The circuit of claim 7, wherein the direction switching module comprises a single pole double throw switching unit; the single-pole double-throw switch unit is connected between the gating module and the signal conditioning module and is used for changing the differential polarity of the potential difference signal input to the signal conditioning module by switching a physical connection path.
10. A current sampling system, characterized in that it comprises a current sampling circuit according to any one of claims 1 to 9.

Description

Current sampling circuit and current sampling system Technical Field The present application relates to the field of signal sampling technologies, and in particular, to a current sampling circuit and a current sampling system. Background In the field of precision current measurement, especially in semiconductor testing, source Measurement Units (SMUs) and multi-range instruments, it is often necessary to accurately sample multi-range currents from microamperes to amperes. The traditional sampling mode of multi-resistance parallel switching is adopted, namely sampling resistance branches with corresponding measuring ranges are gated through a switch, and other branches are disconnected. When the sampling gear is switched, the mode can cause instantaneous interruption of a current loop, cause abrupt change of the working state of a tested circuit, possibly introduce switching noise and voltage spike, and influence system stability and measurement continuity. In addition, each sampling resistor in the parallel structure is independently grounded, is easily influenced by common mode interference and ground loop noise, and reduces sampling precision. Therefore, how to keep the current path continuous and realize high-precision differential measurement in the multi-gear current sampling process is a problem to be solved. Disclosure of Invention The application mainly aims to provide a current sampling circuit and a current sampling system, which aim to solve the technical problems of how to keep a current path continuous and realize high-precision differential measurement in a multi-gear current sampling process. In order to achieve the aim, the application provides a current sampling circuit, which comprises a sampling module, a gating module and a control module, wherein at least two sampling units connected in series are arranged in the sampling module; the sampling module is respectively connected with the equipment to be tested and the gating module, and the control module is respectively connected with the equipment to be tested and the gating module; the control module is used for acquiring current information of the equipment to be tested and transmitting a gating signal to the gating module according to the current information; The gating module is used for selecting a target sampling unit from the sampling module to sample the current to be detected transmitted by the equipment to be detected according to the gating signal; the sampling module is used for generating a corresponding potential difference signal according to the current to be detected and transmitting the potential difference signal to the control module through the gating module. In an embodiment, the sampling unit includes: Sampling resistor, balance capacitor and bypass switch; The first end of the sampling resistor is connected with the first end of the balance capacitor, the first end of the bypass switch, the equipment to be tested and the gating module respectively, and the second end of the sampling resistor is connected with the second end of the balance capacitor, the second end of the bypass switch and the gating module respectively. In one embodiment, the gating module comprises a potential acquisition unit and a channel selection unit; The input end of the potential acquisition unit is connected with the nodes of each sampling unit in the sampling module and is used for acquiring potential difference signals of each node; the channel selection unit is respectively connected with the output end of the potential acquisition unit and the control module; The channel selection unit is configured to select, from the potential difference signals of the nodes, a potential difference signal corresponding to the target sampling unit according to the strobe signal, and output the potential difference signal to the control module. In one embodiment, the control module comprises an information acquisition unit, a signal generation unit and a signal receiving unit; the information acquisition unit is connected with the equipment to be detected and is used for acquiring current information of the equipment to be detected; The signal generating unit is connected with the information acquisition unit and is used for generating the gating signal according to the current information and transmitting the gating signal to the gating module; The signal receiving unit is connected with the gating module and is used for receiving the potential difference signal transmitted by the gating module. In one embodiment, the potential acquisition unit comprises at least three voltage followers; the input end of the voltage follower is connected with the node of each sampling unit in the sampling module, and the output end of the voltage follower is connected with the channel selection unit. In one embodiment, the circuit further comprises a signal conditioning module; the signal conditioning module is connected between the gating module and the control modul