CN214480554U - USB multi-isolation type analog quantity acquisition module - Google Patents

Abstract

The utility model discloses a USB multi-isolation type analog quantity acquisition module, which comprises a communication circuit, a control circuit and an analog acquisition circuit, and is characterized in that the communication circuit supplies power to the control circuit through a first isolation power supply and communicates with the control circuit through a first isolation chip; the control circuit supplies power to the analog acquisition circuit through a second isolation power supply and communicates with the analog acquisition circuit through a second isolation chip; the externally input true differential bipolar signal is acquired by the analog acquisition circuit. The utility model discloses utilize digital isolation technique, power isolation technique realizes the high accuracy collection to true difference, wide voltage input analog quantity. The application of the isolation chip and the isolation power supply effectively improves the sampling precision and the anti-interference capability of the system.

Description

USB multi-isolation type analog quantity acquisition module

Technical Field

The utility model relates to a signal acquisition technical field, in particular to many isolated forms of USB analog quantity collection module.

Background

The method is characterized in that a plurality of industrial control occasions need to collect true differential bipolar analog quantity signals, and the method is limited by the complexity of a power supply and is often difficult to realize.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a many isolated forms of USB analog quantity collection module to the not enough that prior art exists, it only uses the USB interface to provide power and signal transmission, through the reasonable application of keeping apart the power and keeping apart the chip, makes simulation acquisition circuit, control circuit, communication circuit three keep apart completely, has strong interference killing feature, and analog circuit's collection precision is higher, analog circuit input supports true differential bipolar voltage input, has more extensive range of application.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a USB multi-isolation type analog quantity acquisition module comprises a communication circuit, a control circuit and an analog acquisition circuit, wherein the communication circuit supplies power to the control circuit through a first isolation power supply and communicates with the control circuit through a first isolation chip; the control circuit supplies power to the analog acquisition circuit through a second isolation power supply and communicates with the analog acquisition circuit through a second isolation chip; the externally input true differential bipolar signal is acquired by the analog acquisition circuit.

In a preferred embodiment of the present invention, the first isolation chip is divided into a first isolation chip communication circuit side and a first isolation chip control circuit side, and the first isolation power supply is divided into a first isolation power supply communication circuit side and a first isolation power supply control circuit side; the second isolation chip is divided into a second isolation chip control circuit side and a second isolation chip analog acquisition circuit side, and the second isolation power supply is divided into a second isolation power supply control circuit side and a second isolation power supply analog acquisition circuit side;

the communication circuit comprises a PC machine for collecting and displaying signals and a USB-TTL signal conversion chip, wherein the PC machine is provided with a USB interface, the USB interface provides a USB-5V power supply for a power supply end of the USB-TTL signal conversion chip, a power supply end on the communication circuit side of the first isolation chip and the communication circuit side of the first isolation power supply, and a differential signal of the USB interface is converted into a TTL level signal through the USB-TTL chip and then is input to a signal end on the communication circuit side of the first isolation chip;

the control circuit comprises an MCU module and an LDO4+ module, and a serial port of the MCU module is communicated with a PC (personal computer) in the communication circuit through a first isolation chip control circuit side and communicated with the analog acquisition circuit through a second isolation chip control circuit side; the 5V output of the first isolation power supply control circuit side is connected to the power supply input ends of the second isolation power supply control circuit side and the LDO4+ module, and the D3.3V output by the power supply output end of the LDO4+ module is connected to the power supply end of the second isolation chip control circuit side, the power supply end of the MCU module and the power supply end of the first isolation chip control circuit side; the SPI port of the MCU module is connected to a signal end on the side of the second isolation chip control circuit;

the analog acquisition circuit comprises an ADC module, a signal attenuation and anti-aliasing filter, an LDO1+ module, an LDO2+ module, an LDO 3-module, a charge pump and a voltage reference module; the output +5V _ iso of the analog acquisition circuit side of the second isolation power supply is connected to the power supply input ends of the LDO1+ module, the LDO2+ module, the charge pump and the voltage reference module; the 3.3V power output by the LDO1+ module is connected to the digital power VIO end of the ADC module and the power end of the analog acquisition circuit side of the second isolation chip, the A2.5V power output by the LDO2+ module is connected to the analog power AVDD end of the ADC module and the power end of the signal attenuation and anti-aliasing filter, the charge pump converts the +5V _ iso from the analog acquisition circuit side of the second isolation power into-5V _ iso which is connected to the power input of the LDO 3-module, the-2.5V output by the LDO 3-module is connected to a REF-end and an AVSS end of the ADC module, a power supply end of a signal attenuation and anti-aliasing filter and an input end of a voltage reference module, the power reference module receives +5V _ iso from the analog acquisition circuit side of the second isolation power supply and-2.5V of the LDO 3-module, the output R2.5V is connected to the REF + end of the ADC module, and an SPI port of the ADC module is connected to a signal end of the analog acquisition circuit side of the second isolation chip; the externally input true differential bipolar signal passes through the signal attenuation and anti-aliasing filter and enters the analog input port AIN0 … … AIN15 of the ADC module.

In a preferred embodiment of the present invention, the ADC module is a high resolution ADC module, and realizes a true differential, wide voltage analog signal input.

Since the technical scheme as above is adopted, the utility model discloses utilize digital isolation technique, power isolation technique realizes the high accuracy collection to true difference, wide voltage input analog quantity. The application of the isolation chip and the isolation power supply effectively improves the sampling precision and the anti-interference capability of the system.

The utility model discloses utilize digital isolation technique, power isolation technique adopts the high accuracy ADC chip, and special data collection algorithm, the MCU of ARM nuclear forms one set of high accuracy, and interference immunity is strong, wide voltage range's data acquisition system.

The utility model has the advantages of it is following:

1. by adopting the signal attenuation unit and the anti-aliasing filter, the device can adapt to the signal input in a wide voltage range and the anti-interference effect, and improves the data acquisition precision.

2. The high-precision differential ADC chip and the design of separating an analog power supply and a digital power supply of the ADC are adopted, so that true differential and bipolar analog signal input is realized.

3. The isolation power supply module is adopted, so that the power supplies of the communication module, the control module and the analog acquisition circuit are isolated, the anti-interference performance of the system is improved, and the data acquisition precision is improved.

4. And a digital isolation chip is adopted to isolate signals of the communication module, the control module and the analog acquisition circuit, so that the anti-interference performance of the system is improved, and the data acquisition precision is improved.

5. The USB serial port line is used for power supply and signal transmission, multi-channel and precise analog quantity measurement is achieved, and the USB serial port line is simple and practical.

Drawings

Fig. 1 is an electrical schematic diagram of the USB multi-isolation type analog quantity acquisition module of the present invention.

Detailed Description

The preferred embodiment of the present invention will be described in detail below with reference to fig. 1.

As shown in fig. 1, the utility model provides a USB multi-isolation type analog quantity acquisition module, which comprises a communication circuit 111, a control circuit 222 and an analog acquisition circuit 333, wherein the communication circuit 111 supplies power to the control circuit 222 through a first isolation power supply 44 and communicates with the control circuit 222 through a first isolation chip 33; the control circuit 222 powers the analog acquisition circuit 333 through the second isolated power supply 88 and communicates with the analog acquisition circuit 333 through the second isolated chip 66; the externally input true differential bipolar signal is acquired by the analog acquisition circuit 33. The first isolation chip 33 achieves signal isolation purposes while achieving a level conversion function.

The communication circuit 111 includes a PC 11 for acquiring signal display and a USB-TTL signal conversion chip 22. The PC 11 has a USB interface, the USB interface provides USB-5V power to the power source terminal of the USB-TTL signal conversion chip 33, the power source terminal of the communication circuit side of the first isolation chip 33, and the communication circuit side of the first isolation power source 44, and the differential signal USB-DATA of the USB interface is converted into TTL level signal by the USB-TTL chip 22 and then input to the signal terminal of the communication circuit side of the first isolation chip 33.

The control circuit 222 is a control core and comprises an MCU module 55 and an LDO4+ module 77, wherein a serial port COM of the MCU module 55 controls the circuit side through a first isolation chip 33, the USB-TTL chip 22 is communicated with the PC 11 in the communication circuit 111, and the circuit side is controlled by a second isolation chip 66 to be communicated with the analog acquisition circuit; the 5V output of the control circuit side of the first isolation power supply 44 is connected to the control circuit side of the second isolation power supply 88 and the power input end of the LDO4+ module 77, and the D3.3V output of the power output end of the LDO4+ module 77 is connected to the V2 power supply end of the control circuit side of the second isolation chip 66, the VCC power supply end of the MCU module 55 and the power supply end of the control circuit side of the first isolation chip 33; the SPI port of the MCU module 55 is connected to the signal terminal DATA on the control circuit side of the second isolated chip 66.

Analog acquisition circuit 333 the analog acquisition circuit uses a high resolution ADC to achieve true differential, wide voltage analog signal input. The device comprises an ADC module bb, a signal attenuation and anti-aliasing filter ff, an LDO1+ module 99, an LDO2+ module aa, an LDO 3-module ee, a charge pump cc and a voltage reference module dd; the second isolation power supply 88 simulates that the output +5V _ iso at the acquisition circuit side is connected to the power supply input ends of the LDO1+ module 99, the LDO2+ module aa, the charge pump cc and the voltage reference module dd; the 3.3V power output by the LDO1+ module 99 is connected to the digital power VIO end of the ADC module bb and the power end V1 of the analog acquisition circuit side of the second isolation chip 66, the A2.5V power output by the LDO2+ module aa is connected to the AVDD end of the analog power of the ADC module and the power end of the signal attenuation and anti-aliasing filter ff, the charge pump cc converts the +5V _ iso from the analog acquisition circuit side of the second isolation power 88 into-5V _ iso to be connected to the power input of the LDO 3-module ee, the-2.5V output by the LDO 3-module ee is connected to the REF-end and the AVSS end of the ADC module bb, the power end of the signal attenuation and anti-aliasing filter ff, and the input end of the voltage reference module dd, the power reference module dd receives the +5V _ iso from the analog acquisition circuit side of the second isolation power 88 and the-2.5V of the LDO 3-module ee, the output R2.5V is connected to the REF + end of the ADC module bb, an SPI port of the ADC module bb is connected to a signal end DATA of the analog acquisition circuit side of the second isolation chip 66; the externally input true differential bipolar signal passes through the signal attenuation and anti-aliasing filter ff and enters the analog input port AIN0 … … AIN15 of the ADC block bb.

While the present invention has been described in detail with reference to the preferred embodiments thereof, it should be understood that the above description should not be taken as limiting the present invention. Numerous modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the foregoing description. Accordingly, the scope of the invention should be limited only by the attached claims.

Claims (3)

1. A USB multi-isolation type analog quantity acquisition module comprises a communication circuit, a control circuit and an analog acquisition circuit, and is characterized in that the communication circuit supplies power to the control circuit through a first isolation power supply and communicates with the control circuit through a first isolation chip; the control circuit supplies power to the analog acquisition circuit through a second isolation power supply and communicates with the analog acquisition circuit through a second isolation chip; the externally input true differential bipolar signal is acquired by the analog acquisition circuit.

2. The USB multi-isolation type analog quantity acquisition module according to claim 1, wherein the first isolation chip is divided into a first isolation chip communication circuit side and a first isolation chip control circuit side, and the first isolation power supply is divided into a first isolation power supply communication circuit side and a first isolation power supply control circuit side; the second isolation chip is divided into a second isolation chip control circuit side and a second isolation chip analog acquisition circuit side, and the second isolation power supply is divided into a second isolation power supply control circuit side and a second isolation power supply analog acquisition circuit side;

the communication circuit comprises a PC machine for collecting and displaying signals and a USB-TTL signal conversion chip, wherein the PC machine is provided with a USB interface, the USB interface provides a USB-5V power supply for a power supply end of the USB-TTL signal conversion chip, a power supply end on the communication circuit side of the first isolation chip and the communication circuit side of the first isolation power supply, and a differential signal of the USB interface is converted into a TTL level signal through the USB-TTL chip and then is input to a signal end on the communication circuit side of the first isolation chip;

the control circuit comprises an MCU module and an LDO4+ module, and a serial port of the MCU module is communicated with a PC (personal computer) in the communication circuit through a first isolation chip control circuit side and communicated with the analog acquisition circuit through a second isolation chip control circuit side; the 5V output of the first isolation power supply control circuit side is connected to the power supply input ends of the second isolation power supply control circuit side and the LDO4+ module, and the D3.3V output by the power supply output end of the LDO4+ module is connected to the power supply end of the second isolation chip control circuit side, the power supply end of the MCU module and the power supply end of the first isolation chip control circuit side; the SPI port of the MCU module is connected to a signal end on the side of the second isolation chip control circuit;

the analog acquisition circuit comprises an ADC module, a signal attenuation and anti-aliasing filter, an LDO1+ module, an LDO2+ module, an LDO 3-module, a charge pump and a voltage reference module; the output +5V _ iso of the analog acquisition circuit side of the second isolation power supply is connected to the power supply input ends of the LDO1+ module, the LDO2+ module, the charge pump and the voltage reference module; the 3.3V power output by the LDO1+ module is connected to the digital power VIO end of the ADC module and the power end of the analog acquisition circuit side of the second isolation chip, the A2.5V power output by the LDO2+ module is connected to the analog power AVDD end of the ADC module and the power end of the signal attenuation and anti-aliasing filter, the charge pump converts the +5V _ iso from the analog acquisition circuit side of the second isolation power into-5V _ iso which is connected to the power input of the LDO 3-module, the-2.5V output by the LDO 3-module is connected to a REF-end and an AVSS end of the ADC module, a power supply end of a signal attenuation and anti-aliasing filter and an input end of a voltage reference module, the power reference module receives +5V _ iso from the analog acquisition circuit side of the second isolation power supply and-2.5V of the LDO 3-module, the output R2.5V is connected to the REF + end of the ADC module, and an SPI port of the ADC module is connected to a signal end of the analog acquisition circuit side of the second isolation chip; the externally input true differential bipolar signal passes through the signal attenuation and anti-aliasing filter and enters the analog input port AIN0 … … AIN15 of the ADC module.

3. The USB multi-isolation type analog acquisition module of claim 2, wherein the ADC module is a high resolution ADC module, implementing true differential, wide voltage analog signal input.

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