CN104807559A - Multi-channel low-temperature measuring circuit supporting multiple sensors - Google Patents
Multi-channel low-temperature measuring circuit supporting multiple sensors Download PDFInfo
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- CN104807559A CN104807559A CN201510181747.6A CN201510181747A CN104807559A CN 104807559 A CN104807559 A CN 104807559A CN 201510181747 A CN201510181747 A CN 201510181747A CN 104807559 A CN104807559 A CN 104807559A
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Abstract
The invention discloses a multi-channel low-temperature measuring circuit supporting multiple sensors. The multi-channel low-temperature measuring circuit supporting the multiple sensors comprises a reference voltage generation circuit, eight constant-current source circuits, a channel selection circuit and an analog to digital conversion circuit. The 2.5V reference voltage outputted by a reference voltage generation chip ADR421 in the reference voltage generation circuit is used by the eight constant-current source circuits and the analog to digital conversion circuit, the current outputted by the constant-current source circuits flows to the eight temperature sensors connected with temperature sensor interfaces in the channel selection circuit, the voltage generated by the temperature sensors is processed in a mode that an analog multiplexer selects one signal to conduct AD conversion, and temperature measurement of the temperature sensors is achieved through timed switching of channels. According to the multi-channel low-temperature measuring circuit supporting the multiple sensors, temperature measurement of the eight channels is supported, four kinds of excitation current are set for each channel, one kind of excitation current can be selected by each channel according to the type of the temperature sensors, and the type of the supported sensors is greatly extended.
Description
Technical field
The present invention relates to low temperature measurement technical field, particularly relate to a kind of multi-channel low-temperature metering circuit supporting multiple sensors.
Background technology
At present, for low temperature measurement field, be especially low to moderate liquid helium, the thermometric circuit solutions in liquid nitrogen temperature has a lot of defect.The excitation electric flow valuve being generally used for stimulus sensor is all fixing, causes the sensor type of circuit compatibility to be limited in very little scope; Secondly, the temperature measuring channel that large multicircuit is supported is fewer, causes a lot of waste in extensive low temperature measurement field.
Summary of the invention
The object of the invention is exactly the defect in order to make up prior art, provides a kind of multi-channel low-temperature metering circuit supporting multiple sensors.
The present invention is achieved by the following technical solutions:
A kind of multi-channel low-temperature metering circuit supporting multiple sensors, include reference voltage generating circuit, eight constant-current source circuits, channel selection circuit and analog to digital conversion circuit, in described reference voltage generating circuit, reference voltage produces the 2.5V reference voltage of chip ADR421 output respectively for eight constant-current source circuits and analog to digital conversion circuit, the electric current of eight constant-current source circuit outputs all flows to temperature sensor interface institute Jie No. eight temperature sensor in channel selection circuit, the voltage that No. eight temperature sensors produce selects a wherein road signal to carry out AD analog to digital conversion through analog multiplexer, the temperature survey of temperature sensor is realized by exchange-column shift passage.
Described reference voltage generating circuit comprises reference voltage and produces chip ADR421, and second pin of reference voltage generation chip ADR421 connects the positive pole of+15V power supply VCC+15V, tantalum electric capacity C1 and C2 respectively, and the negative pole of tantalum electric capacity C1 and C2 meets AGND in analog; The 4th pin that reference voltage produces chip ADR421 meets AGND in analog, and the 6th pin of chip ADR421 connects the positive pole of the 4th pin of eight instrument amplifier AD8221, tantalum electric capacity C13, C14 respectively, and the negative pole of tantalum electric capacity C13, C14 meets AGND in analog.
Circuit component and the element connected mode of eight described constant-current source circuits are identical, first via constant-current source circuit comprises instrument amplifier AD8221, 4th pin of instrument amplifier AD8221 connects the 6th pin that reference voltage produces chip ADR421, first pin of instrument amplifier AD8221 meets AGND in analog, second of instrument amplifier AD8221, three pins are unsettled, 5th pin of instrument amplifier AD8221 meets-15V power supply VCC-15V respectively, the negative pole of tantalum electric capacity C18 and C20, the positive pole of tantalum electric capacity C18 and C20 meets AGND in analog, 6th pin of instrument amplifier AD8221 connects the 6th pin of amplifier one OPA602, 7th pin of instrument amplifier AD8221 meets thousand-island forest park metalfilmresistor R2 respectively, R6, R10, one end of R14, 4th pin of another termination analog multiplexer ADG1409 of resistance R2, 5th pin of another termination analog multiplexer ADG1409 of resistance R6, 6th pin of another termination analog multiplexer ADG1409 of resistance R10, 7th pin of another termination analog multiplexer ADG1409 of resistance R14, 14 pin of analog multiplexer ADG1409 meets+15V power supply VCC+15V, 3rd pin of analog multiplexer ADG1409 meets-15V power supply VCC-15V, 8th pin of analog multiplexer ADG1409 connects the 3rd pin of amplifier OPA602 respectively, first pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, second pin of amplifier OPA602 connects the 6th pin of amplifier one OPA602,4th pin of amplifier one OPA602 connects the negative pole of-15V power supply VCC-15V and tantalum electric capacity C25 respectively, the positive pole of tantalum electric capacity C25 meets AGND in analog, 7th pin of amplifier one OPA602 connects the positive pole of+15V power supply VCC+15V and tantalum electric capacity C28 respectively, and the negative pole of tantalum electric capacity C28 meets AGND in analog, in second road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 3rd pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 3rd road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 5th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 4th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 7th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 5th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 9th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 6th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 11 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 7th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 13 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 8th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 15 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2.
Described channel selection circuit includes the double contact pin J1 of eight road temperature sensor interface 16P*2, and first, second and third 12 and 31 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects I+, V+, I-and V-end of first via temperature sensor respectively, the double contact pin J1 of eight road temperature sensor interface 16P*2 third and fourth, 30 and 29 pins connect respectively No. second temperature sensor I+, V+, I-and V-end, 5th, six, 28 and 27 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. three temperature sensor respectively, 7th, eight, 26 and 25 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. four temperature sensor respectively, 9th, ten, 24 and 23 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. five temperature sensor respectively, 11,12,22 and 21 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. six temperature sensor respectively, 13,14,20 and 19 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. seven temperature sensor respectively, 15,16,18 and 17 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. eight temperature sensor respectively, simultaneously the double contact pin J1 of eight road temperature sensor interface 16P*2 the 17, 19, 21, 23, 25, 27, 29 and 31 pins connect second pin of amplifier OP177, the 18 of the double contact pin J1 of eight road temperature sensor interface 16P*2, 20, 22, 24, 26, 28, 30 and 32 pins connect the 6th pin of amplifier OP177, 3rd pin of amplifier OP177 meets AGND in analog, 4th pin of amplifier OP177 connects-15V power supply respectively, the negative pole of tantalum electric capacity C66 and C67, the positive pole of tantalum electric capacity C66 and C67 meets AGND in analog, 7th pin of amplifier OP177 connects+15V power supply respectively, the positive pole of tantalum electric capacity C64 and C65, the negative pole of tantalum electric capacity C64 and C65 meets AGND in analog, second pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 4th pin of analog multiplexer ADG5408,4th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 5th pin of analog multiplexer ADG5408,6th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 6th pin of analog multiplexer ADG5408,8th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 7th pin of analog multiplexer ADG5408, tenth pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 12 pin of analog multiplexer ADG5408,12 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 11 pin of analog multiplexer ADG5408,14 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the tenth pin of analog multiplexer ADG5408,16 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 9th pin of analog multiplexer ADG5408, 3rd pin of analog multiplexer ADG5408 connects the negative pole of-15 power supply VCC-15V and tantalum electric capacity C63 respectively, the positive pole of C63 meets AGND in analog, second pin of analog multiplexer ADG5408 meets+5V power supply VCC+5V, 14 pin of analog multiplexer ADG5408 meets AGND in analog, 8th pin of analog multiplexer ADG5408 connects the 3rd pin of amplifier OPA602,13 pin of analog multiplexer ADG5408 connects the positive pole of+15V power supply VCC+15V and tantalum electric capacity C60 respectively, and the negative pole of C60 meets AGND in analog.
Described analog to digital conversion circuit comprises amplifier two OPA602 and modulus conversion chip AD7193, second pin of amplifier two OPA602 connects the 6th pin of amplifier two OPA602 and the 11 pin of modulus conversion chip AD7193 respectively, 7th pin of amplifier two OPA602 connects the positive pole of+15 power supply VCC+15V and tantalum electric capacity C61 respectively, the negative pole of C61 meets AGND in analog, 4th pin of amplifier two OPA602 connects the negative pole of-15V power supply VCC-15V and tantalum electric capacity C62 respectively, the 8th pin of partial simulation multiplexer ADG5408 is selected in the 3rd pin completes road of amplifier two OPA602, 12 pin of modulus conversion chip AD7193 meets AGND in analog, 19 pin of modulus conversion chip AD7193 connects the 6th pin of reference voltage generating section chip ADR421, 20 pin of modulus conversion chip AD7193 meets AGND in analog, 9th pin of modulus conversion chip AD7193 meets AGND in analog, 22 pin of modulus conversion chip AD7193 meets AGND in analog, 23 pin of modulus conversion chip AD7193 meets digitally DGND, 24 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V and tantalum electric capacity C124 respectively, the positive pole of C125, the negative pole of C124 and C125 meets AGND in analog, 25 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V and tantalum electric capacity C121 respectively, the positive pole of C122, the negative pole of C121 and C122 meets digitally DGND, 26 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V, 4th pin of modulus conversion chip AD7193 meets digitally DGND, digitally DGND is connected by zero Europe resistance R106 with AGND in analog.
Advantage of the present invention is: the present invention supports the temperature survey of eight passages, each channel setting four kinds of exciting currents, every passage can according to the type selecting of temperature sensor wherein a kind of exciting current, greatly extend the type supporting sensor, each passage can compatible various temperature sensor, greatly extends temperature-measuring range.
Accompanying drawing explanation
Fig. 1 is metering circuit one-piece construction schematic diagram of the present utility model.
Fig. 2 is reference voltage circuit.
Fig. 3 is first via constant-current source circuit.
Fig. 4 is sensor interface and channel selection circuit.
Fig. 5 is analog to digital conversion circuit.
Embodiment
As shown in Figure 1, a kind of structure principle chart supporting the multi-channel low-temperature metering circuit of multiple sensors, include reference voltage generating circuit 1, eight constant-current source circuits 2, 3, 4, 5, 6, 7, 8, 9, sensor interface and channel selection circuit 10 and analog to digital conversion circuit 11, the 2.5V reference voltage exported in described reference voltage generating circuit 1 is respectively for eight constant-current source circuits and analog to digital conversion circuit, the electric current of eight constant-current source circuit outputs all flows to temperature sensor interface institute Jie No. eight temperature sensor in sensor interface and channel selection circuit 10, the voltage that No. eight temperature sensors produce selects a wherein road signal to carry out AD analog to digital conversion through analog multiplexer, the temperature survey of temperature sensor is realized by exchange-column shift passage.
As shown in Figure 2, described reference voltage generating circuit 1 comprises reference voltage and produces chip ADR421, second pin of reference voltage generation chip ADR421 connects the positive pole of+15V power supply VCC+15V, tantalum electric capacity C1 and C2 respectively, and the negative pole of tantalum electric capacity C1 and C2 meets AGND in analog; The 4th pin that reference voltage produces chip ADR421 meets AGND in analog, and the 6th pin of chip ADR421 connects the positive pole of the 4th pin of eight instrument amplifier AD8221, tantalum electric capacity C13, C14 respectively, and the negative pole of tantalum electric capacity C13, C14 meets AGND in analog.
As shown in Figure 3, circuit component and the element connected mode of eight described constant-current source circuits are identical, first via constant-current source circuit 2 comprises instrument amplifier AD8221, 4th pin of instrument amplifier AD8221 connects the 6th pin that reference voltage produces chip ADR421, first pin of instrument amplifier AD8221 meets AGND in analog, second of instrument amplifier AD8221, three pins are unsettled, 5th pin of instrument amplifier AD8221 meets-15V power supply VCC-15V respectively, the negative pole of tantalum electric capacity C18 and C20, the positive pole of tantalum electric capacity C18 and C20 meets AGND in analog, 6th pin of instrument amplifier AD8221 connects the 6th pin of amplifier one OPA602, 7th pin of instrument amplifier AD8221 meets thousand-island forest park metalfilmresistor R2 respectively, R6, R10, one end of R14, 4th pin of another termination analog multiplexer ADG1409 of resistance R2, 5th pin of another termination analog multiplexer ADG1409 of resistance R6, 6th pin of another termination analog multiplexer ADG1409 of resistance R10, 7th pin of another termination analog multiplexer ADG1409 of resistance R14, 14 pin of analog multiplexer ADG1409 meets+15V power supply VCC+15V, 3rd pin of analog multiplexer ADG1409 meets-15V power supply VCC-15V, 8th pin of analog multiplexer ADG1409 connects the 3rd pin of amplifier OPA602 respectively, first pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, second pin of amplifier OPA602 connects the 6th pin of amplifier one OPA602,4th pin of amplifier one OPA602 connects the negative pole of-15V power supply VCC-15V and tantalum electric capacity C25 respectively, the positive pole of tantalum electric capacity C25 meets AGND in analog, 7th pin of amplifier one OPA602 connects the positive pole of+15V power supply VCC+15V and tantalum electric capacity C28 respectively, and the negative pole of tantalum electric capacity C28 meets AGND in analog, in second road constant-current source circuit 3, the 8th pin of analog multiplexer ADG1409 connects the 3rd pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 3rd road constant-current source circuit 4, the 8th pin of analog multiplexer ADG1409 connects the 5th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 4th road constant-current source circuit 5, the 8th pin of analog multiplexer ADG1409 connects the 7th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 5th road constant-current source circuit 6, the 8th pin of analog multiplexer ADG1409 connects the 9th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 6th road constant-current source circuit 7, the 8th pin of analog multiplexer ADG1409 connects the 11 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 7th road constant-current source circuit 8, the 8th pin of analog multiplexer ADG1409 connects the 13 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 8th road constant-current source circuit 9, the 8th pin of analog multiplexer ADG1409 connects the 15 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2.
As shown in Figure 4, described channel selection circuit 10 includes the double contact pin J1 of eight road temperature sensor interface 16P*2, and first, second and third 12 and 31 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects I+, V+, I-and V-end of first via temperature sensor respectively, the double contact pin J1 of eight road temperature sensor interface 16P*2 third and fourth, 30 and 29 pins connect respectively No. second temperature sensor I+, V+, I-and V-end, 5th, six, 28 and 27 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. three temperature sensor respectively, 7th, eight, 26 and 25 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. four temperature sensor respectively, 9th, ten, 24 and 23 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. five temperature sensor respectively, 11,12,22 and 21 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. six temperature sensor respectively, 13,14,20 and 19 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. seven temperature sensor respectively, 15,16,18 and 17 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. eight temperature sensor respectively, simultaneously the double contact pin J1 of eight road temperature sensor interface 16P*2 the 17, 19, 21, 23, 25, 27, 29 and 31 pins connect second pin of amplifier OP177, the 18 of the double contact pin J1 of eight road temperature sensor interface 16P*2, 20, 22, 24, 26, 28, 30 and 32 pins connect the 6th pin of amplifier OP177, 3rd pin of amplifier OP177 meets AGND in analog, 4th pin of amplifier OP177 connects-15V power supply respectively, the negative pole of tantalum electric capacity C66 and C67, the positive pole of tantalum electric capacity C66 and C67 meets AGND in analog, 7th pin of amplifier OP177 connects+15V power supply respectively, the positive pole of tantalum electric capacity C64 and C65, the negative pole of tantalum electric capacity C64 and C65 meets AGND in analog, second pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 4th pin of analog multiplexer ADG5408,4th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 5th pin of analog multiplexer ADG5408,6th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 6th pin of analog multiplexer ADG5408,8th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 7th pin of analog multiplexer ADG5408, tenth pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 12 pin of analog multiplexer ADG5408,12 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 11 pin of analog multiplexer ADG5408,14 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the tenth pin of analog multiplexer ADG5408,16 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 9th pin of analog multiplexer ADG5408, 3rd pin of analog multiplexer ADG5408 connects the negative pole of-15 power supply VCC-15V and tantalum electric capacity C63 respectively, the positive pole of C63 meets AGND in analog, second pin of analog multiplexer ADG5408 meets+5V power supply VCC+5V, 14 pin of analog multiplexer ADG5408 meets AGND in analog, 8th pin of analog multiplexer ADG5408 connects the 3rd pin of amplifier OPA602,13 pin of analog multiplexer ADG5408 connects the positive pole of+15V power supply VCC+15V and tantalum electric capacity C60 respectively, and the negative pole of C60 meets AGND in analog.
As shown in Figure 5, described analog to digital conversion circuit 11 comprises amplifier two OPA602 and modulus conversion chip AD7193, second pin of amplifier two OPA602 connects the 6th pin of amplifier two OPA602 and the 11 pin of modulus conversion chip AD7193 respectively, 7th pin of amplifier two OPA602 connects the positive pole of+15 power supply VCC+15V and tantalum electric capacity C61 respectively, the negative pole of C61 meets AGND in analog, 4th pin of amplifier two OPA602 connects the negative pole of-15V power supply VCC-15V and tantalum electric capacity C62 respectively, the 8th pin of partial simulation multiplexer ADG5408 is selected in the 3rd pin completes road of amplifier two OPA602, 12 pin of modulus conversion chip AD7193 meets AGND in analog, 19 pin of modulus conversion chip AD7193 connects the 6th pin of reference voltage generating section chip ADR421, 20 pin of modulus conversion chip AD7193 meets AGND in analog, 9th pin of modulus conversion chip AD7193 meets AGND in analog, 22 pin of modulus conversion chip AD7193 meets AGND in analog, 23 pin of modulus conversion chip AD7193 meets digitally DGND, 24 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V and tantalum electric capacity C124 respectively, the positive pole of C125, the negative pole of C124 and C125 meets AGND in analog, 25 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V and tantalum electric capacity C121 respectively, the positive pole of C122, the negative pole of C121 and C122 meets digitally DGND, 26 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V, 4th pin of modulus conversion chip AD7193 meets digitally DGND, digitally DGND is connected by zero Europe resistance R106 with AGND in analog.
The 2.5V reference voltage that in reference voltage generating section, ADR421 exports is respectively for eight road constant-current source circuit and analog to digital conversion circuits, 10 partial activation institute Jie No. eight sensors in the equal flow graph of electric current that eight road constant current sources export, the voltage that No. eight sensors produce selects a wherein road signal to carry out AD analog to digital conversion through analog multiplexer, is realized the voltage measurement of No. eight sensors by exchange-column shift passage.
In the embodiment depicted in figure 2, for ensureing the stability of reference voltage, tantalum electric capacity C13, C14 of output terminal difference 10uF and 0.1uF in parallel of reference voltage.Simultaneously for ensureing the stability of supply voltage, at the tantalum electric capacity C2 of tantalum electric capacity C1 and 10uF an of+15V voltage output end difference 0.1uF in parallel.
Embodiment illustrated in fig. 3 is the circuit theory diagrams of first via constant current source, the 2.5V reference voltage exported in Fig. 2 is input to the 4th pin of instrument amplifier AD8221, first pin of AD8221 connects in analog, second of AD8221, three pins do not connect, now the enlargement factor of AD8221 is 1, the voltage difference of AD8221 the 7th pin and the 6th pin is made to be 2.5V, again because the profound and negative feedbck of U11 amplifier OPA602 makes the 3rd pin of OPA602 equal with the 6th pin voltage of AD8221, therefore the voltage difference between the 7th pin of AD8221 and the 3rd pin of OPA602 is 2.5V.In figure, U4 is four road difference analogue multiplexer ADG1409, as the second enable ADG1409 of pin EN input high level, selects wherein a pair differential signal to output to pin DA to hold and DB holds by the first pin A0 and the 16 pin A1.Only used an input channel of often pair of differential signal in the circuit, namely only selector channel S1A, S2A, S3A and S4A Zhong mono-road signal output to DA end.When ADG1409 gating wherein a road signal time, its maximum conducting resistance is only 4 ohm, therefore can not produce a very large impact the all-in resistance in path.In the circuit, the 4th pin of first passage ADG1409 connects 2.5k Ω resistance, and during gating, channel current is 1mA; 5th pin of second channel ADG1409 connects 5k Ω resistance, and during gating, channel current is 500uA; 6th pin of third channel ADG1409 connects 25k Ω resistance, and during gating, channel current is 100uA; 7th pin of four-way ADG1409 connects 250k Ω resistance, and during gating, channel current is 10uA; Simultaneously when the second pin sheet choosing end EN of ADG1409 is low level, channel current is 0.
Embodiment illustrated in fig. 4ly comprise eight road temperature sensor interfaces and sensor passage selection part.In figure, the double contact pin J1 of 16P*2 is eight road sensor interfaces.Sensor uses four endings, and four ends are respectively V+, V-, I+ and I-end; In figure, first, second and third 12 and 31 pin of J1 is I+, V+, I-and V-end of first via sensor respectively; J1 third and fourth, 30 and 29 pins be respectively No. second sensor I+, V+, I-and V-end; 5th, six, 28 and 27 pins of J1 are I+, V+, I-and V-end of three-way sensor respectively; 7th, eight, 26 and 25 pins of J1 are I+, V+, I-and V-end of No. four sensor respectively; 9th, ten, 24 and 23 pins of J1 are I+, V+, I-and V-end of No. five sensor respectively; 11,12,22 and 21 pins of J1 are I+, V+, I-and V-end of No. six sensor respectively; 13,14,20 and 19 pins of J1 are I+, V+, I-and V-end of No. seven sensor respectively; 15,16,18 and 17 pins of J1 are I+, V+, I-and V-end of No. eight sensor respectively; In figure, amplifier OP177 adopts Kelvin connection, makes the V-terminal voltage of each road sensor for current potential in analog, therefore only needs to gather the voltage of V+ end on each sensor passage.In figure, the V+ of each sensor passage is held, namely second, four, six, eight, ten, 12,14 and 16 pins of J1 be connected to respectively analog multiplexer ADG5408 first, second, third and fourth, five, six, seven and eight passages, i.e. fourth, fifth, six, seven, 12,11, ten and nine pins of ADG5408.ADG5408 selects eight signal Zhong mono-road, road signals to export the 8th pin of ADG5408 to by first, 16 and 15 pins.In figure, ADG5408 is the stability ensureing supplying DC+15V and-15V power supply, respectively tantalum electric capacity C60 and C63 of a 0.1uF in parallel in power pins.In figure, tantalum electric capacity C64, C65 and C66 of the tantalum electric capacity of+15V of amplifier OP177 and-15 power pins 10uF all in parallel and 0.1uF, C67, ensure the stability of power supply.
Voltage for exporting temperature sensor embodiment illustrated in fig. 5 carries out analog to digital conversion.The impact damper of the voltage that sensor exports first through being made up of OPA602, reduces sensor and exports the excessive impact produced AD conversion of internal resistance.The 11 pin AIN1 of the signal input modulus conversion chip AD7193 of Buffer output, the 12 pin AIN2 ground connection of AD7193, AIN1 and AIN2 forms a differential input signal pair.The reference voltage of AD7193 uses the 2.5V reference voltage that in Fig. 2, ADR421 the 6th pin exports, and namely the 19 pin of AD7193 connects 2.5V reference voltage, and the 20 pin connects in analog.Owing to not only there is artificial circuit part but also there is digital circuits section in AD7193 chip, in the circuit by one zero Europe resistance R106 will in analog with digitally isolate, to reduce the interference of digital signal to simulating signal.25 number of pins word voltage and the 24th pin analog power of AD7193 all use+5V power supply, and all at the power end tantalum electric capacity of a 10uF in parallel and the tantalum electric capacity of a 0.1uF.
Claims (5)
1. support the multi-channel low-temperature metering circuit of multiple sensors for one kind, it is characterized in that: include reference voltage generating circuit, eight constant-current source circuits, channel selection circuit and analog to digital conversion circuit, in described reference voltage generating circuit, reference voltage produces the 2.5V reference voltage of chip ADR421 output respectively for eight constant-current source circuits and analog to digital conversion circuit, the electric current of eight constant-current source circuit outputs all flows to temperature sensor interface institute Jie No. eight temperature sensor in channel selection circuit, the voltage that No. eight temperature sensors produce selects a wherein road signal to carry out AD analog to digital conversion through analog multiplexer, the temperature survey of temperature sensor is realized by exchange-column shift passage.
2. a kind of multi-channel low-temperature metering circuit supporting multiple sensors according to claim 1, it is characterized in that: described reference voltage generating circuit comprises reference voltage and produces chip ADR421, second pin of reference voltage generation chip ADR421 connects the positive pole of+15V power supply VCC+15V, tantalum electric capacity C1 and C2 respectively, and the negative pole of tantalum electric capacity C1 and C2 meets AGND in analog; The 4th pin that reference voltage produces chip ADR421 meets AGND in analog, and the 6th pin of chip ADR421 connects the positive pole of the 4th pin of eight instrument amplifier AD8221, tantalum electric capacity C13, C14 respectively, and the negative pole of tantalum electric capacity C13, C14 meets AGND in analog.
3. a kind of multi-channel low-temperature metering circuit supporting multiple sensors according to claim 1, it is characterized in that: circuit component and the element connected mode of eight described constant-current source circuits are identical, first via constant-current source circuit comprises instrument amplifier AD8221, 4th pin of instrument amplifier AD8221 connects the 6th pin that reference voltage produces chip ADR421, first pin of instrument amplifier AD8221 meets AGND in analog, second of instrument amplifier AD8221, three pins are unsettled, 5th pin of instrument amplifier AD8221 meets-15V power supply VCC-15V respectively, the negative pole of tantalum electric capacity C18 and C20, the positive pole of tantalum electric capacity C18 and C20 meets AGND in analog, 6th pin of instrument amplifier AD8221 connects the 6th pin of amplifier one OPA602, 7th pin of instrument amplifier AD8221 meets thousand-island forest park metalfilmresistor R2 respectively, R6, R10, one end of R14, 4th pin of another termination analog multiplexer ADG1409 of resistance R2, 5th pin of another termination analog multiplexer ADG1409 of resistance R6, 6th pin of another termination analog multiplexer ADG1409 of resistance R10, 7th pin of another termination analog multiplexer ADG1409 of resistance R14, 14 pin of analog multiplexer ADG1409 meets+15V power supply VCC+15V, 3rd pin of analog multiplexer ADG1409 meets-15V power supply VCC-15V, 8th pin of analog multiplexer ADG1409 connects the 3rd pin of amplifier OPA602 respectively, first pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, second pin of amplifier OPA602 connects the 6th pin of amplifier one OPA602,4th pin of amplifier one OPA602 connects the negative pole of-15V power supply VCC-15V and tantalum electric capacity C25 respectively, the positive pole of tantalum electric capacity C25 meets AGND in analog, 7th pin of amplifier one OPA602 connects the positive pole of+15V power supply VCC+15V and tantalum electric capacity C28 respectively, and the negative pole of tantalum electric capacity C28 meets AGND in analog, in second road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 3rd pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 3rd road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 5th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 4th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 7th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 5th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 9th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 6th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 11 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 7th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 13 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2, in 8th road constant-current source circuit, the 8th pin of analog multiplexer ADG1409 connects the 15 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2.
4. a kind of multi-channel low-temperature metering circuit supporting multiple sensors according to claim 1, it is characterized in that: described channel selection circuit includes the double contact pin J1 of eight road temperature sensor interface 16P*2, first, second and third 12 and 31 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects I+, V+, I-and V-end of first via temperature sensor respectively, the double contact pin J1 of eight road temperature sensor interface 16P*2 third and fourth, 30 and 29 pins connect respectively No. second temperature sensor I+, V+, I-and V-end, 5th, six, 28 and 27 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. three temperature sensor respectively, 7th, eight, 26 and 25 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. four temperature sensor respectively, 9th, ten, 24 and 23 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. five temperature sensor respectively, 11,12,22 and 21 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. six temperature sensor respectively, 13,14,20 and 19 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. seven temperature sensor respectively, 15,16,18 and 17 pins of the double contact pin J1 of eight road temperature sensor interface 16P*2 connect I+, V+, I-and V-end of No. eight temperature sensor respectively, simultaneously the double contact pin J1 of eight road temperature sensor interface 16P*2 the 17, 19, 21, 23, 25, 27, 29 and 31 pins connect second pin of amplifier OP177, the 18 of the double contact pin J1 of eight road temperature sensor interface 16P*2, 20, 22, 24, 26, 28, 30 and 32 pins connect the 6th pin of amplifier OP177, 3rd pin of amplifier OP177 meets AGND in analog, 4th pin of amplifier OP177 connects-15V power supply respectively, the negative pole of tantalum electric capacity C66 and C67, the positive pole of tantalum electric capacity C66 and C67 meets AGND in analog, 7th pin of amplifier OP177 connects+15V power supply respectively, the positive pole of tantalum electric capacity C64 and C65, the negative pole of tantalum electric capacity C64 and C65 meets AGND in analog, second pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 4th pin of analog multiplexer ADG5408,4th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 5th pin of analog multiplexer ADG5408,6th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 6th pin of analog multiplexer ADG5408,8th pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 7th pin of analog multiplexer ADG5408, tenth pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 12 pin of analog multiplexer ADG5408,12 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 11 pin of analog multiplexer ADG5408,14 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the tenth pin of analog multiplexer ADG5408,16 pin of the double contact pin J1 of eight road temperature sensor interface 16P*2 connects the 9th pin of analog multiplexer ADG5408, 3rd pin of analog multiplexer ADG5408 connects the negative pole of-15 power supply VCC-15V and tantalum electric capacity C63 respectively, the positive pole of C63 meets AGND in analog, second pin of analog multiplexer ADG5408 meets+5V power supply VCC+5V, 14 pin of analog multiplexer ADG5408 meets AGND in analog, 8th pin of analog multiplexer ADG5408 connects the 3rd pin of amplifier OPA602,13 pin of analog multiplexer ADG5408 connects the positive pole of+15V power supply VCC+15V and tantalum electric capacity C60 respectively, and the negative pole of C60 meets AGND in analog.
5. a kind of multi-channel low-temperature metering circuit supporting multiple sensors according to claim 1, it is characterized in that: described analog to digital conversion circuit comprises amplifier two OPA602 and modulus conversion chip AD7193, second pin of amplifier two OPA602 connects the 6th pin of amplifier two OPA602 and the 11 pin of modulus conversion chip AD7193 respectively, 7th pin of amplifier two OPA602 connects the positive pole of+15 power supply VCC+15V and tantalum electric capacity C61 respectively, the negative pole of C61 meets AGND in analog, 4th pin of amplifier two OPA602 connects the negative pole of-15V power supply VCC-15V and tantalum electric capacity C62 respectively, the 8th pin of partial simulation multiplexer ADG5408 is selected in the 3rd pin completes road of amplifier two OPA602, 12 pin of modulus conversion chip AD7193 meets AGND in analog, 19 pin of modulus conversion chip AD7193 connects the 6th pin of reference voltage generating section chip ADR421, 20 pin of modulus conversion chip AD7193 meets AGND in analog, 9th pin of modulus conversion chip AD7193 meets AGND in analog, 22 pin of modulus conversion chip AD7193 meets AGND in analog, 23 pin of modulus conversion chip AD7193 meets digitally DGND, 24 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V and tantalum electric capacity C124 respectively, the positive pole of C125, the negative pole of C124 and C125 meets AGND in analog, 25 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V and tantalum electric capacity C121 respectively, the positive pole of C122, the negative pole of C121 and C122 meets digitally DGND, 26 pin of modulus conversion chip AD7193 meets+5V power supply VCC+5V, 4th pin of modulus conversion chip AD7193 meets digitally DGND, digitally DGND is connected by zero Europe resistance R106 with AGND in analog.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106444905A (en) * | 2016-09-19 | 2017-02-22 | 中国科学院合肥物质科学研究院 | High-temperature superconducting welding temperature synchronous measurement controller |
| CN107632261A (en) * | 2016-07-18 | 2018-01-26 | 大众汽车有限公司 | For the method and apparatus at least one state parameter for determining power storage element |
| CN109029552A (en) * | 2018-06-06 | 2018-12-18 | 江南大学 | A kind of optional humiture transducer of multisensor interface analog output |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020014675A1 (en) * | 2000-08-04 | 2002-02-07 | Toru Matsumoto | Semiconductor temperature detecting method and its circuit |
| CN201083792Y (en) * | 2007-06-21 | 2008-07-09 | 吴壬华 | Multichannel photoelectric isolation voltage measurement circuit |
| CN102297730A (en) * | 2011-05-23 | 2011-12-28 | 国网电力科学研究院 | Multi-channel general temperature measurement module |
| CN103123510A (en) * | 2013-01-05 | 2013-05-29 | 赖德龙 | Adjustable constant flow source circuit |
| CN103968969A (en) * | 2013-01-29 | 2014-08-06 | 西门子公司 | Temperature measuring device and chip of system on programmable chip |
-
2015
- 2015-04-16 CN CN201510181747.6A patent/CN104807559A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020014675A1 (en) * | 2000-08-04 | 2002-02-07 | Toru Matsumoto | Semiconductor temperature detecting method and its circuit |
| CN201083792Y (en) * | 2007-06-21 | 2008-07-09 | 吴壬华 | Multichannel photoelectric isolation voltage measurement circuit |
| CN102297730A (en) * | 2011-05-23 | 2011-12-28 | 国网电力科学研究院 | Multi-channel general temperature measurement module |
| CN103123510A (en) * | 2013-01-05 | 2013-05-29 | 赖德龙 | Adjustable constant flow source circuit |
| CN103968969A (en) * | 2013-01-29 | 2014-08-06 | 西门子公司 | Temperature measuring device and chip of system on programmable chip |
Non-Patent Citations (3)
| Title |
|---|
| 尹超平: "基于VIIS_EM平台的虚拟数字集成电路测试仪的设计", 《电子技术应用》 * |
| 张博: "基于双档恒流源的多通道温度采集装置设计", 《仪器仪表与检测技术》 * |
| 陶海军: "基于AD7606的多通道数据采集系统设计", 《工矿自动化》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107632261A (en) * | 2016-07-18 | 2018-01-26 | 大众汽车有限公司 | For the method and apparatus at least one state parameter for determining power storage element |
| CN107632261B (en) * | 2016-07-18 | 2021-06-22 | 大众汽车有限公司 | Method and device for determining at least one state variable of an electrical energy storage element |
| US11340303B2 (en) | 2016-07-18 | 2022-05-24 | Volkswagen Ag | Method and device for determining at least one state variable of a storage element for electrical energy |
| CN106444905A (en) * | 2016-09-19 | 2017-02-22 | 中国科学院合肥物质科学研究院 | High-temperature superconducting welding temperature synchronous measurement controller |
| CN109029552A (en) * | 2018-06-06 | 2018-12-18 | 江南大学 | A kind of optional humiture transducer of multisensor interface analog output |
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