CN105591652A - Six-channel full-isolated 12-bit digital-to-analog conversion board - Google Patents

Abstract

Provided is a six-channel full-isolated 12-bit digital-to-analog conversion board which uses a CPLD (complex programmable logic device) XINLINX XC95216PQ160 in which chip selection decoding and logical operation are both edited. Address lines, data lines, and a control line from the computer interior have access to the CPLD. The address lines A4-9 are decoded to gate on the board. 12-bit data are written into each channel and are latched into a PISO (parallel-in serial-out) shift register. A 12-system counter enables the data to be successively shifted out from low bits to high bits. Each bit of data is shifted out at the rising edge of each shift pulse. The serial data and a control logic signal generated according to a timing sequence is isolated by a high-speed optical coupler HCPL-2630 and then go to the corresponding pins of a D/A chip TI DAC7611U. Data 0 to 4095 correspond to 0.000 to 4.095V respectively. An amplifier TILF444 converts the data into a 0-5V or 4-20mA output signal. The board is compact in structure, achieves optoelectronic isolation between input and output, and effectively inhibits interference of external signals on a system.

Description

The full isolation 12 figure place mould conversion boards of six passages

Technical field:

The present invention relates to D/A converter module, be specifically related to a kind of CBC-DAC-726 D/A converter module.

Background technology:

The analog-digital chip that the multichannel digital-to-analogue conversion board using in industrial control field at present adopts generally allBe that data parallel writes, input and output are not isolated, and poor anti jamming capability at the scene, if input and outputFull isolation, high-speed light lotus root chip is too many, and cost is too high. The data of the each dac channel of this board are onlyOn the spot be incorporated to and go here and there out, realize input and output entirely isolate with minimum high-speed light lotus root chip, cost falls effectivelyLow, increase reliability.

Summary of the invention:

Technical problem to be solved by this invention is to overcome the defect of prior art, provides a kind of structure tightGather, input, output all adopt photoelectricity isolation, effectively suppress the number of the interference of outer signals to systemMould modular converter.

Technical problem to be solved by this invention realizes by the following technical solutions.

The full isolation 12 figure place mould conversion boards of six passages, is characterized in that:

This board adopts XILINXXC95216PQ160CPLD PLD, sheet translate selectively code,Logical operation is all programmed in chip. From address wire, data wire and the control of computer-internal busLine access CPLD, address wire A4～9, through decoding gating board, write 12 bit data to each passage respectivelyAnd be latching to be incorporated to and go here and there out shift register, suitable by the first low level rear high-lyings of 12 system Counter control dataOrder shifts out, and the rising edge of each shift pulse shifts out a data, serial data and the control producing chronologicallyLogical signal processed enters together TIDAC7611UD/A chip after the isolation of HCPL-2630 high-speed light lotus rootRespective pins, data 0～4095 correspondence 0.000～4.095V, by TILF444 amplifier be converted to 0～5V or 4～20mA output signal.

The DC5V working power of this board control section is provided by computer-internal; Peripheral circuit is by isolating electricitySource provides DC5V and DC ± 15V;

Data, address, control line from computer-internal bus access this board through bus slot, instituteIt is soft by XILINXXC95216--PQ160CPLD chip internal that some sheets are translated code, logic control and algorithm selectivelyPart control, grading control chronologically under the effect of external clock, operation softward interview on computersWith certain passage of control or digital quantity position, select corresponding channel number by address decoding, by U274LS245MBidirectional buffer carries out the read-write of data;

Each dac channel is independently, and circuit structure, working method are all identical, first to12 bit registers of this passage write 12 bit data, trigger 12 bit shift register by clock signal clk,By the number of times of 12 system Counter control displacements, control CS, LD, CLK, the sdi signal of DAC7611UBy HCPL-2630 high-speed light lotus root isolation output;

Make the chip selection signal CS step-down level of DAC7611U simultaneously, after 12 bit data end-of-shifts,The chip selection signal CS of DAC7611U uprises level, then triggers the data loading signal LD step-down of DAC7611ULevel, the rising edge signal of next clock cycle CLK is reset to high level, analog signals output simultaneously,DAC7611U and control circuit return to initialization state, wait for next digital-to-analogue conversion; DAC7611U is defeatedGo out DC0-4.095V, amplify DC0-10V or the output of stack biasing circuit through LF444M amplifier homophaseDC2-10V；

Biasing circuit provides accurate DC5V voltage source by reference voltage source REF02EP, bleeder circuit R1,W2, R2, adjust potentiometer W2 and make OP07 operational amplifier output 1.024V;

The voltage signal of DAC7611U output is through amplifier LF444M amplifying circuit;

The voltage signal of this grade of amplifier output, through the current source circuit of rear class be converted to DC0-20mA or4--20mA expands stream output by 9013 triodes.

The input and output of this circuit all adopt the isolation of light lotus root, and power supply is also isolation power supply, makes whole plateJig has very strong antijamming capability, and whole former devices adopt SMD paster technique, suppress to greatest extentNoise.

This board structure compactness, input, output all adopt photoelectricity isolation, effectively suppress outer signalsTo the interference of system.

Brief description of the drawings:

Fig. 1 is control section schematic diagram of the present invention;

Fig. 2 is smooth lotus root isolation output schematic diagram of the present invention;

Fig. 3 is biasing circuit schematic diagram of the present invention;

Fig. 4 is that the voltage signal of DAC7611U of the present invention output is through amplifier LF444M amplifying circuit;

Fig. 5 is the current source circuit conversion schematic diagram of rear class of the present invention;

Fig. 6 is digital quantity input schematic diagram of the present invention;

Fig. 7 is principle schematic of the present invention.

Detailed description of the invention:

For technological means, creation characteristic that the present invention is realized, reach object and effect is easy to understandSeparate, below in conjunction with concrete diagram, further set forth the present invention.

As Fig. 7: the full isolation 12 figure place moulds conversion boards of six passages,

This board adopts XILINXXC95216PQ160CPLD PLD, sheet translate selectively code,Logical operation is all programmed in chip. From address wire, data wire and the control of computer-internal busLine access CPLD, address wire A4～9, through decoding gating board, write 12 bit data to each passage respectivelyAnd be latching to be incorporated to and go here and there out shift register, suitable by the first low level rear high-lyings of 12 system Counter control dataOrder shifts out, and the rising edge of each shift pulse shifts out a data, serial data and the control producing chronologicallyLogical signal processed enters together TIDAC7611UD/A chip after the isolation of HCPL-2630 high-speed light lotus rootRespective pins, data 0～4095 correspondence 0.000～4.095V, by TILF444 amplifier be converted to 0～5V or 4～20mA output signal.

The DC5V working power of this board control section is provided by computer-internal; Peripheral circuit is by isolating electricitySource provides DC5V and DC ± 15V, as shown in Figure 1;

Data, address, control line from computer-internal bus access this board through bus slot, instituteIt is soft by XILINXXC95216--PQ160CPLD chip internal that some sheets are translated code, logic control and algorithm selectivelyPart control, grading control chronologically under the effect of external clock, operation softward interview on computersWith certain passage of control or digital quantity position, select corresponding channel number by address decoding, by U274LS245MBidirectional buffer carries out the read-write of data;

Each dac channel is independently, and circuit structure, working method are all identical, first to12 bit registers of this passage write 12 bit data, trigger 12 bit shift register by clock signal clk,By the number of times of 12 system Counter control displacements, control CS, LD, CLK, the sdi signal of DAC7611UBy HCPL-2630 high-speed light lotus root isolation output, as shown in Figure 2;

Make the chip selection signal CS step-down level of DAC7611U simultaneously, after 12 bit data end-of-shifts,The chip selection signal CS of DAC7611U uprises level, then triggers the data loading signal LD step-down of DAC7611ULevel, the rising edge signal of next clock cycle CLK is reset to high level, analog signals output simultaneously,DAC7611U and control circuit return to initialization state, wait for next digital-to-analogue conversion; DAC7611U is defeatedGo out DC0-4.095V, amplify DC0-10V or the output of stack biasing circuit through LF444M amplifier homophaseDC2-10V；

Biasing circuit provides accurate DC5V voltage source by reference voltage source REF02EP, bleeder circuit R1,W2, R2, adjust potentiometer W2 and make OP07 operational amplifier output 1.024V, as shown in Figure 3;

The voltage signal of DAC7611U output is through amplifier LF444M amplifying circuit, as Fig. 4;

The voltage signal of this grade of amplifier output, through the current source circuit of rear class be converted to DC0-20mA or4--20mA expands stream output by 9013 triodes, as Fig. 5.

The input and output of this circuit all adopt the isolation of light lotus root, and power supply is also isolation power supply, makes whole plateJig has very strong antijamming capability, and whole former devices adopt SMD paster technique, suppresses to greatest extent to make an uproarSound, as Fig. 6.

More than show and described general principle of the present invention, principal character and advantage of the present invention. One's own professionThe technical staff of industry should understand, and the present invention is not restricted to the described embodiments, above-described embodiment and explanationThat in book, describes just illustrates principle of the present invention, without departing from the spirit and scope of the present invention,The present invention also has various changes and modifications, and these changes and improvements all fall into claimed model of the present inventionIn enclosing. The claimed scope of the present invention is defined by appending claims and equivalent thereof.

Claims (3)

1. the full isolation 12 figure place mould conversion boards of six passages, is characterized in that:

This board adopts XILINXXC95216PQ160CPLD PLD, sheet translate selectively code,Logical operation is all programmed in chip. From address wire, data wire and the control of computer-internal busLine access CPLD, address wire A4～9, through decoding gating board, write 12 bit data to each passage respectivelyAnd be latching to be incorporated to and go here and there out shift register, suitable by the first low level rear high-lyings of 12 system Counter control dataOrder shifts out, and the rising edge of each shift pulse shifts out a data, serial data and the control producing chronologicallyLogical signal processed enters together TIDAC7611UD/A chip after the isolation of HCPL-2630 high-speed light lotus rootRespective pins, data 0～4095 correspondence 0.000～4.095V, by TILF444 amplifier be converted to 0～5V or 4～20mA output signal.

2. according to the full isolation 12 figure place mould conversion boards of six passages described in claim 1, its featureBe: the DC5V working power of this board control section is provided by computer-internal; Peripheral circuit is by isolatingPower supply provides DC5V and DC ± 15V;

Data, address, control line from computer-internal bus access this board through bus slot, instituteIt is soft by XILINXXC95216--PQ160CPLD chip internal that some sheets are translated code, logic control and algorithm selectivelyPart control, grading control chronologically under the effect of external clock, operation softward interview on computersWith certain passage of control or digital quantity position, select corresponding channel number by address decoding, by U274LS245MBidirectional buffer carries out the read-write of data;

Each dac channel is independently, and circuit structure, working method are all identical, first to12 bit registers of this passage write 12 bit data, trigger 12 bit shift register by clock signal clk,By the number of times of 12 system Counter control displacements, control CS, LD, CLK, the sdi signal of DAC7611UBy HCPL-2630 high-speed light lotus root isolation output;

Make the chip selection signal CS step-down level of DAC7611U simultaneously, after 12 bit data end-of-shifts,The chip selection signal CS of DAC7611U uprises level, then triggers the data loading signal LD step-down of DAC7611ULevel, the rising edge signal of next clock cycle CLK is reset to high level, analog signals output simultaneously,DAC7611U and control circuit return to initialization state, wait for next digital-to-analogue conversion; DAC7611U is defeatedGo out DC0-4.095V, amplify DC0-10V or the output of stack biasing circuit through LF444M amplifier homophaseDC2-10V；

Biasing circuit provides accurate DC5V voltage source by reference voltage source REF02EP, bleeder circuit R1,W2, R2, adjust potentiometer W2 and make OP07 operational amplifier output 1.024V;

The voltage signal of DAC7611U output is through amplifier LF444M amplifying circuit;

The voltage signal of this grade of amplifier output, through the current source circuit of rear class be converted to DC0-20mA or4--20mA expands stream output by 9013 triodes.

3. according to the full isolation 12 figure place mould conversion boards of six passages described in claim 1, its featureBe: the input and output of this circuit all adopt the isolation of light lotus root, power supply is also isolation power supply; Whole first devicesPart adopts SMD paster technique.