CN202918273U - Analog quantity digitization isolation device - Google Patents

Abstract

The utility model relates to an analog quantity digitization isolation device. The analog quantity digitization isolation device comprises an analog quantity signal input module. The analog quantity signal input module comprises a digital-to-analog conversion chip ADS7953 which is used to convert an analog quantity into a digital quantity. The analog quantity signal input module is connected with a CPU module, wherein the analog quantity is converted into a digital quantity and then is transferred to the CPU module in a communication manner. According to the analog quantity digitization isolation device of the utility model, a digital-to-analog conversion chip ADS7953 is added into the analog quantity signal input module, an analog quantity is converted into a digital quantity, and then the digital quantity is transferred to the CPU module through a communication transmission circuit module having the signal isolation function, no external isolation module is needed, advantages of small size and low cost can be realized; the analog quantity is converted into a digital quantity and then is transferred in a communication manner, so advantages of high analog quantity accuracy, good anti-interference ability and less failure can be realized.

Description

A kind of analog quantity digitlization spacer assembly

Technical field

The utility model relates to a kind of analog quantity digitlization spacer assembly.

Background technology

The analog quantity isolation is isolated analog signal exactly, to guarantee the integrality of analog quantity.Analog signal mainly is the signal relative with discrete digital signal, analog signal refers to represent information with the continually varying physical quantity, the amplitude of its signal or frequency or phase place at any time intercropping change continuously, it is present in each corner of nature, such as the variations in temperature of every day, and digital signal is artificial abstract in time discontinuous signal out.Analog signal is easy to be interfered in transmission course, so in a lot of systems, analog signal is all isolated.The circuit parameter that analog signal is considered is different from digital signal fully, and analog signal will be considered first usually: precision or the linearity, frequency response, noise are considered.

At present, in the application of each control device, mostly need to isolate for inputing or outputing of analog signal, at present, mainly contain following four kinds of isolation methods, wherein the application of isolation amplifier is the most common.

1. photoelectricity isolation: adopt photoelectric isolating device, change into light signal by the signal of telecommunication and change into again the signal of telecommunication, reach input stage to the isolation of output stage.

2. voltage device isolation: the input coil induction of signal of transformer realizes full isolation to output winding.

3. degree of flying Capacitor apart: because it is to utilize relay switch to come Isolation input signal port and instrument port, therefore employing speed is slower.

4. isolation amplifier isolation: the isolation features that utilizes isolation amplifier to carry reaches the purpose of isolation.

And these present partition methods, the precision of analog quantity is not high, and the volume of module is large, poor anti jamming capability, and cost is high.

The utility model content

The problem that exists for solving prior art, the utility model provides the analog quantity digitlization that a kind of analog quantity precision is high, the module volume is little, antijamming capability is strong and cost is low spacer assembly.

Analog quantity digitlization spacer assembly described in the utility model, comprise the analog signals input module, described analog signals input module comprises for the analog-digital chip ADS7953 that analog quantity is converted to digital quantity, described analog signals input module connects the CPU module, and analog quantity sends the CPU module to by communication mode after being converted to digital quantity.

Described analog signals input module connecting analog amount sampling module and AD module, the communications circuit module of described analog quantity sampling module and the isolation of AD module connecting band signal, the communications circuit module of described band signal isolation connects the CPU module.

Analog quantity digitlization spacer assembly described in the utility model, its beneficial effect is:

Add an analog-digital chip ADS7953 at the analog signals input module, analog quantity is converted to digital quantity after, the communications circuit module by band signal isolation with digital transfer to the CPU module, need not external isolation module, volume is little, cost is low; Transmit in the mode of communication by analog quantity being converted to digital quantity, the analog quantity precision is high, antijamming capability is strong again, and fault is few.

Description of drawings

The picture that this description of drawings provides is used for assisting the further understanding to utility model, consists of the application's a part, does not consist of to improper restriction of the present utility model, in the accompanying drawings:

Accompanying drawing 1 is the structural representation of the utility model analog quantity digitlization spacer assembly.

Embodiment

The below will describe the utility model in detail with specific embodiment, be used for explaining the utility model in this illustrative examples of the present utility model and explanation, but not as to restriction of the present utility model.

Shown in accompanying drawing 1 ~ 2, analog quantity digitlization spacer assembly described in the utility model, comprise the analog signals input module, described analog signals input module comprises that one is used for analog quantity is converted to the analog-digital chip ADS7953 of digital quantity, described analog signals input module connecting analog amount sampling module and AD module, the communications circuit module of described analog quantity sampling module and the isolation of AD module connecting band signal, the communications circuit module of described band signal isolation connects the CPU module, ADS7953 is a 12/18 multipath A/D converter, be equipped with the electric capacity SAR A/D converter of built-in employing retainer, it accepts wide region analog quantity supply voltage, the characteristic of super low-power consumption makes it be applicable to the application of powered battery and isolated power supply, 1.7V to the wide I/O supply district of 5.25V help to realize and the most frequently used cmos digital main frame between without cementing port, analog quantity sends the CPU module to by communication mode after being converted to digital quantity by analog-digital chip ADS7953.

The analog signals input module enters amplifier with the shaping first time of analog quantity by the RC circuit of input, finally enter modulus conversion chip become behind the digital quantity by and CPU between communication protocol send among the CPU, isolation to analog quantity in this process mainly is to utilize the mode of serial communication SCL to achieve the goal by modulus conversion chip, modulus conversion chip comprises the two-way power supply, with the power supply access chip of two-way isolation, the isolation technology that utilizes like this chip to carry reaches the isolation of analog quantity when circuit design.With the transmission of the signal of CPU be ADS7953 with serial line interface cross a transmission lines by data communication device and send out owing to adopting Digital Transmission, can not have influence on the completeness of analog signals, so higher reliability and good frequency are arranged.

The present invention can apply in the various analog quantity sample circuits take microprocessor as core because these devices usually need to be between two disparate modules the transfer die analog signal, and to guarantee safe and reliable transmission.Current potential between common two disparate modules may differ several hectovolts even several kilovolts, such as isolation armature supply and the voltage sensor in the electric machine controller, and the isolation on motor ground and control system ground etc.Particularly can be used in some power electronic equipments take microprocessor as core, this reference signal that needs transmission to represent output characteristic, and the power circuit and the control circuit that run on the HF switch state often are different from the general circuit plate, in order to prevent that the strong electromagnetic string from causing system's operation exception to microsystem, and reduce EMI and power frequency is disturbed.

The present invention is used at present the entire car controller of independent research, and the analog quantity of its input has all been adopted the digitlization isolation, and the normal isolation technology that uses has obvious advantage at present.

Adopted the entire car controller of this analog quantity digitlization spacer assembly to be provided with 15 road analog inputs, the basic data with input of the output data after the isolation match.Artificial adding electromagnetic interference in the process of debugging does not impact the analog quantity of input substantially.

This novel analog quantity digitlization spacer assembly decrease the use cost of analog module, this time in the entire car controller of utilization and independent research, the analog quantity processing module has adopted some electronic components commonly used such as a modulus conversion chip ADS7953 and resistance, electric capacity, and the total cost valency of all electronic components is no more than 200 yuan.And now most of what adopt is isolation amplifier to the isolation of analog quantity in the controller, the higher isolation amplifier chip of sexual valence the chances are on the market at present 80 yuan/.Each isolation amplifier chip with analog quantity channel be maximum be two, so come the isolation of settling signal in the analog quantity sampling module of above-mentioned entire car controller such as the employing isolation amplifier, then need at least 8 isolation amplifier chips, namely the analog quantity sampling module needs 700 yuan of fee of materials at least.And 8 required spaces of isolation amplifier are far longer than a space that modulus conversion chip is required, so adopt this novel analog amount digitlization spacer assembly because the electric elements quantity of using reduces, thereby so that the failure rate that has reduced module is reduced in the fault point of module.

The above technical scheme that the utility model embodiment is provided is described in detail, this paper has used specific case principle and the execution mode of the utility model embodiment has been set forth, and the explanation of above embodiment is only applicable to help to understand the principle of the utility model embodiment; Simultaneously, for one of ordinary skill in the art, according to the utility model embodiment, all will change on embodiment and range of application, in sum, this description should not be construed as restriction of the present utility model.

Claims (2)

1. an analog quantity digitlization spacer assembly comprises the analog signals input module, it is characterized in that:

Described analog signals input module comprises for the analog-digital chip ADS7953 that analog quantity is converted to digital quantity, described analog signals input module connection CPU module, and analog quantity sends the CPU module to by communication mode after being converted to digital quantity.

2. analog quantity digitlization spacer assembly as claimed in claim 1 is characterized in that:

Described analog signals input module connecting analog amount sampling module and AD module, the communications circuit module of described analog quantity sampling module and the isolation of AD module connecting band signal, the communications circuit module of described band signal isolation connects the CPU module.

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