WO2020006696A1

WO2020006696A1 - Adc-based detection circuit, and microprocessor-based detection circuit

Info

Publication number: WO2020006696A1
Application number: PCT/CN2018/094439
Authority: WO
Inventors: 韩旺
Original assignee: 深圳市锐明技术股份有限公司
Priority date: 2018-07-04
Filing date: 2018-07-04
Publication date: 2020-01-09
Also published as: CN211377086U

Abstract

An ADC-based detection circuit comprises: two or more detection sub-circuits (20) connected in series between an input port of an ADC (11) and the ground. The input port of the ADC (11) is connected to a power supply (Vc) via a first resistor (R1). Each of the detection sub-circuits (20) comprises a switch transistor (Q1) and a second resistor (R2), a control terminal of the switch transistors (Q1) serves as an external detection node of a detection terminal of the detection sub-circuit (20), a low voltage terminal of the switch transistor (Q1) is grounded, and a high voltage terminal of the switch transisitor (Q1) is connected to the input port of the ADC (11) via the resistor. The ADC (11) determines, according to a voltage level of the input port, whether a corresponding detection node is in a normal or abnormal state, and outputs a corresponding digital signal at an output port. One port is used to perform detection on multiple circuit nodes and to determine an abnormal condition. No matter if the ADC (11) is built in or provided outside of a microprocessor, only one pin of the ADC (11) is occupied, thereby releasing resources of I/O ports.

Description

Detection circuit based on ADC and detection circuit based on microprocessor

Technical field

The present application belongs to the technical field of electronic circuits, and particularly relates to an ADC (Analog-to-Digital Converter, digital-to-analog converter or analog-to-digital converter) detection circuit and microprocessor-based detection circuit.

Background technique

At present, traditional electronic systems that include a processor often require the detection of abnormal output voltages (short circuit, open circuit, or lower than a specific value) at all levels of the power supply. Generally, the resistance is used to directly divide the voltage and then sent to the I / O port of the microcontroller to make a judgment. It needs an I / O port to detect a voltage. Obviously, this design requires that the microcontroller has more I / O ports.

Therefore, the conventional electronic system has a problem that detecting multiple electrical signals requires multiple I / O ports, which occupies a large amount of microprocessor I / O resources.

technical problem

The traditional electronic system has a problem that using a processor to detect multiple electrical signals requires multiple I / O ports.

Technical solutions

A detection circuit based on an ADC. The ADC has an input port and an output port, and includes: two or more detection branches connected in parallel between an input port of the ADC and a ground, and an input port of the ADC passes A first resistor is connected to the power source, and each of the detection branches includes a switch tube and a second resistor. The control end of the switch tube is used as the detection end of the detection branch to connect to the detection node, and the low-potential end of the switch tube. The high potential end of the switch is connected to the input port of the ADC through the resistor. The ADC determines the normal or abnormal state of the corresponding detection node according to the voltage value of the input port and outputs a corresponding digital signal at the output port. .

In one embodiment, each detection branch further includes a current limiting resistor, and the current limiting resistor is connected between the detection node and a control terminal of the switch.

In one embodiment, the switch is a transistor, an IGBT or a MOSFET.

In one embodiment, the switching transistor is an NPN-type transistor, an N-type IGBT, or an N-type MOSFET;

The base of the NPN transistor, the gate of the N-type IGBT, the gate of the N-type MOSFET, the control terminal of the switching transistor, the collector of the NPN-type transistor, the collector of the N-type IGBT, and the drain of the N-type MOSFET are described The high-potential end of the switch, the emitter of the NPN triode, the emitter of the N-IGBT, and the source of the N-MOSFET are the low-potential ends of the switch.

In one embodiment, the resistance values of the second resistors on each detection branch are not equal.

In addition, a microprocessor-based detection circuit is provided, which includes the above-mentioned ADC-based detection circuit, and the ADC is internally or externally disposed to the microprocessor.

Beneficial effect

The above microprocessor-based detection circuit sets multiple detection branches and is connected in parallel to an input port of an ADC. The ADC sets a detection voltage and abnormal relationship table, and determines whether the corresponding detection node is normal or abnormal according to the voltage value of the input port. Status and output corresponding digital signals at the output port. In this way, one port can be used to detect multiple circuit nodes and determine abnormal conditions. Whether the ADC is built in or external to the microprocessor, it only takes up microprocessing. An ADC pin of the processor releases the pressure of the microprocessor I / O port resources.

BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic circuit diagram of an example of a microprocessor-based detection circuit according to an embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of an example of a microprocessor-based detection circuit according to another embodiment of the present invention.

Embodiments of the invention

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

Please refer to FIG. 1, an ADC-based detection circuit according to an embodiment of the present invention. The ADC 11 has an input port and an output port. The ADC-based detection circuit can be applied to a microprocessor-based (MCU) detection. In the circuit, ADC is applied 11 is internally or externally placed in the microprocessor 10. ADC When 11 is built in, the input port of ADC 11 is used as the ADC (I / O) pin of microprocessor 10. When ADC 11 is externally connected, the output port of ADC 11 Feet connected. The microprocessor 10 may be a microcontroller, an ARM (Advanced RISC Machine, advanced reduced instruction set computer) controller, etc.

Specifically, the detection circuit based on the ADC 11 includes: two or more channels connected in parallel to the ADC Detection branch 20 between the input port of 11 and ground, the ADC The input port of 11 is connected to the power source Vc through a first resistor R1. Each of the detection branches 20 includes a switch Q1 and a second resistor R2. The control terminal of the switch Q1 is used as the detection terminal of the detection branch 20. An external detection node is connected, and the low-potential end of the switch Q1 is grounded. The high-potential end of the switch Q1 is connected to the input port of the ADC 11 through the resistor. 11 Determine the normal or abnormal state of the corresponding detection node according to the voltage value of the input port and output the corresponding digital signal at the output port.

To set reasonable parameters of the first and second resistors, the switch Q1 must be operated in the off or saturated state (switching state). In this embodiment, the resistance values of the second resistor R2 on each detection branch 20 are not equal.

The switching transistor Q1 is a transistor, an IGBT or a MOSFET. Specifically, the switching transistor Q1 is an NPN-type transistor, an N-type IGBT, or an N-type MOSFET; the base of the NPN-type transistor, the gate of the N-type IGBT, and the gate of the N-type MOSFET; the control end of the switching transistor Q1, NPN The collector of the triode, the collector of the N-type IGBT, and the drain of the N-type MOSFET are described in the high-potential terminal of the switch Q1, the emitter of the NPN-type transistor, the emitter of the N-type IGBT, and the source of the N-type MOSFET. Low potential terminal of the switch Q1.

In one embodiment, each detection branch 20 further includes a current limiting resistor R3, and the current limiting resistor R3 is connected between the detection node and the control terminal of the switch Q1. The first resistor R1 and the second resistor R2 are voltage-dividing resistors. The first resistor R1, the second resistor R2, and the current-limiting resistor R3 can all be implemented by using one resistor or multiple resistors in series and parallel.

Please refer to FIG. 2 to explain the working principle of the detection circuit according to an embodiment. When two circuit nodes (such as power supply, voltage, or current) that need to be detected are connected to the detection nodes in the schematic diagram, respectively, point 1, test node test point 1, test node test point is normally 3.3 V and abnormal is 0 V.

Setting: When the input voltage is normal, the switch Q1 is turned on. When the input voltage is abnormal, the switch Q1 is turned off. The transistor here is equivalent to a switch.

When detecting the two voltages, there are 4 cases, which are both abnormal, and both are normal: testing point 1 is abnormal, test point 2 is normal, test point 1 is normal, test point 2 is abnormal. Each case corresponds to a unique voltage value Vo of the input port of the ADC 11 (where R2 ≠ R3). Through the sampling and comparison of the ADC 11, we can know the abnormality of these two voltages. The voltage value Vo and the abnormal condition of the detection node are as follows:

检测支路20情况描述 Detect branch 20 condition description	两路都正常 Both are normal	1异常、2正常 1 abnormal, 2 normal	1正常、2异常 1 normal, 2 abnormal	两路都异常 Both paths are abnormal
Vo设置计算值 Vo set the calculated value	2.03V 2.03V	3.4V 3.4V	2.5V 2.5V	5.0V 5.0V
Vo实际测量值 Vo actual measured value	2.04V 2.04V	3.44V 3.44V	2.52V 2.52V	4.97V 4.97V
Vo设置范围 Vo setting range	[1.70V,2.30V] [1.70V, 2.30V]	[3.00V,4.00V] [3.00V, 4.00V]	[2.30V,3.00V] [2.30V, 3.00V]	[4.50V,5.20V] [4.50V, 5.20V]

The above-mentioned microprocessor-based detection circuit is provided with a plurality of detection branches 20 and connected in parallel to an ADC. On the 11 input port, the ADC 11 sets the detection voltage and abnormal relationship table. According to the voltage value of the input port, determine the normal or abnormal state of the corresponding detection node and output the corresponding digital signal at the output port. Circuit nodes to detect and be able to determine abnormal conditions, whether the ADC 11 When built-in or external to the microprocessor 10, it also occupies only one ADC pin of the microprocessor 10, releasing the pressure of the I / O port resources of the microprocessor 10.

The above description is only the preferred embodiments of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims

A detection circuit based on an ADC. The ADC has one input port and one output port, and is characterized in that it includes two or more detection branches connected in parallel between an input port of the ADC and a ground, and the ADC. The input port is connected to the power supply through a first resistor. Each of the detection branches includes a switch tube and a second resistor. The control end of the switch tube is connected to the detection node as the detection end of the detection branch. The switch tube The low-potential terminal of the switch is connected to the ground. The high-potential terminal of the switch is connected to the input port of the ADC through the resistor. The ADC determines the normal or abnormal state of the corresponding detection node according to the voltage value of the input port and outputs it at the output port. Corresponding digital signal.
The detection circuit based on the ADC according to claim 1, wherein each detection branch further comprises a current limiting resistor, and the current limiting resistor is connected between the detection node and a control terminal of the switch. between.
The detection circuit based on the ADC according to claim 1, wherein the switching transistor is a triode, an IGBT, or a MOSFET.
The detection circuit based on the ADC according to claim 3, wherein the switch is an NPN-type transistor, an N-type IGBT, or an N-type MOSFET;

The base of the NPN transistor, the gate of the N-type IGBT, the gate of the N-type MOSFET, the control terminal of the switching transistor, the collector of the NPN-type transistor, the collector of the N-type IGBT, and the drain of the N-type MOSFET are described The high-potential end of the switch, the emitter of the NPN triode, the emitter of the N-IGBT, and the source of the N-MOSFET are the low-potential ends of the switch.
The detection circuit based on the ADC according to claim 1, wherein the resistance values of the second resistors on each detection branch are not equal.
A microprocessor-based detection circuit, comprising the detection circuit based on the ADC according to any one of claims 1 to 5, wherein the ADC is internally or externally provided to the microprocessor.