CN207051438U - One kind test card reader - Google Patents
One kind test card reader Download PDFInfo
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- CN207051438U CN207051438U CN201720967860.1U CN201720967860U CN207051438U CN 207051438 U CN207051438 U CN 207051438U CN 201720967860 U CN201720967860 U CN 201720967860U CN 207051438 U CN207051438 U CN 207051438U
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- 238000012360 testing method Methods 0.000 title claims abstract description 35
- 238000006243 chemical reaction Methods 0.000 claims description 38
- 230000000087 stabilizing effect Effects 0.000 claims description 27
- 238000005070 sampling Methods 0.000 claims description 23
- 230000003750 conditioning effect Effects 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 6
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011990 functional testing Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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Abstract
The utility model provides a kind of test card reader.The test card reader includes processor, D/A converting circuit, serial voltage regulation circuit and current foldback circuit；Wherein, the data output end of processor is connected to the input of digital analog converter, and different input signals is provided to digital analog converter, and the output end of digital analog converter is connected to the input of serial voltage regulation circuit.Serial voltage regulation circuit includes reference voltage circuit, sample circuit, comparison amplifier and adjustment element, reference voltage circuit is resistor voltage divider circuit, the output end of the both ends connection digital analog converter of reference voltage circuit, the component voltage of reference voltage circuit are connected to the reference voltage terminal of comparison amplifier.The output end of serial voltage regulation circuit provides operating voltage to chip to be measured, can realize to chip to be measured and provide different size and stable output voltage.
Description
Technical Field
The utility model relates to an integrated circuit tests technical field, especially relates to a test card reader.
Background
With the continuous development of integrated circuit technology, the application of smart cards is becoming more and more extensive, and test card readers are devices for testing smart cards and are used for testing the performance of the smart cards.
At present, a test card reader is mainly a commercial card reader provided based on different products, and an operating voltage provided for a smart card to be tested is usually a fixed voltage, such as 3V or 5V, and such a voltage is usually a working voltage of the smart card, and is suitable for functional tests.
SUMMERY OF THE UTILITY MODEL
To the not enough that exists among the above-mentioned prior art, the utility model aims at providing a test card reader, treater, digital analog conversion circuit, tandem type voltage stabilizing circuit and overcurrent protection circuit interconnect's structure for tandem type voltage stabilizing circuit output is enlarged and stable voltage, in order to provide the chip that awaits measuring, realizes providing not equidimension and stable output voltage to the chip that awaits measuring.
In order to achieve the technical purpose, the utility model discloses the technical scheme who adopts is:
a test card reader comprises a processor, a digital-to-analog conversion circuit, a series voltage stabilizing circuit and an overcurrent protection circuit; the data output end of the processor is connected to the input end of the digital-to-analog conversion circuit and provides different input signals for the digital-to-analog conversion circuit; the output end of the digital-to-analog conversion circuit is connected to the input end of the series voltage stabilizing circuit, and a signal output by the processor is converted into direct-current voltage; the output end of the series voltage stabilizing circuit is connected with the input end of the overcurrent protection circuit, and the direct-current voltage output by the digital-to-analog conversion circuit is used as the input voltage of the series voltage stabilizing circuit; the overcurrent protection circuit prevents the output current of the series voltage stabilizing circuit from exceeding the maximum allowable load value.
Preferably, the series voltage regulator circuit includes a reference voltage circuit, a sampling circuit, a comparison amplifier, and an adjustment element.
Preferably, the reference voltage circuit is a resistance voltage dividing circuit, two ends of the reference voltage circuit are connected to the output end of the digital-to-analog conversion circuit, and the divided voltage of the reference voltage circuit is connected to the reference voltage end of the comparison amplifier.
Preferably, the overcurrent protection circuit comprises a triode and a resistor, a base of the triode is connected to a current output end of the adjusting element, the current output end of the adjusting element is connected to one end of the resistor, a collector of the triode is connected to the base of the adjusting element, and an emitter of the triode is connected to the other end of the resistor.
Preferably, the test card reader further comprises a voltage sampling circuit and a first analog-to-digital conversion circuit, and the output voltage of the series voltage stabilizing circuit sequentially passes through the voltage sampling circuit and the first analog-to-digital conversion circuit and then is connected to the processor.
Preferably, the test card reader further comprises a current sampling circuit and a second analog-to-digital conversion circuit, and the output current of the series voltage stabilizing circuit sequentially passes through the current sampling circuit and the second analog-to-digital conversion circuit and then is connected to the processor.
Preferably, the test card reader further comprises a display connected to the processor.
Preferably, the test card reader further comprises a keyboard connected to the processor.
The utility model discloses a test card reader is owing to adopt the treater, digital-analog conversion circuit, tandem type voltage stabilizing circuit and overcurrent protection circuit interconnect's structure, the beneficial effect who obtains is, output at the treater is connected with digital-analog conversion circuit, the different voltage signal of treater output, make digital-analog conversion circuit output not equidimension direct current voltage, the output voltage of tandem type voltage stabilizing circuit's reference voltage circuit connection digital-analog conversion circuit, when digital-analog conversion circuit exports not equidimension voltage, the reference voltage circuit provides not reference voltage of equidimension, thereby tandem type voltage stabilizing circuit output is enlarged and stable voltage, in order to provide the chip that awaits measuring, the realization provides not equidimension and stable output voltage to the chip that awaits measuring.
The present invention will be further described with reference to the accompanying drawings and the following detailed description.
Drawings
Fig. 1 is a schematic structural diagram of the test card reader of the present invention.
Fig. 2 is a schematic structural diagram of a test card reader implemented in the present invention.
Fig. 3 is a schematic structural diagram of a series voltage stabilizing circuit according to an embodiment of the present invention.
Detailed Description
Referring to fig. 1, it is a schematic structural diagram of the test card reader of the present invention. The test card reader comprises a processor, a digital-to-analog conversion circuit, a series voltage stabilizing circuit and an overcurrent protection circuit. The test card reader is powered by a direct current power supply to power the various active components within the test card reader. The processor is an embedded processor, a test program for testing a chip to be tested is integrated, a data output end of the processor is connected to an input end of the digital-to-analog conversion circuit, voltage input signals with different sizes are provided for the digital-to-analog conversion circuit, the digital-to-analog conversion circuit is used for converting signals output by the processor into direct current voltages, and the digital-to-analog conversion circuit outputs the direct current voltages with different sizes according to the different voltage input signals.
Referring to fig. 2, a schematic structural diagram of a test card reader is shown for implementing the present invention. Referring to fig. 3, a schematic diagram of a structure of a series voltage stabilizing circuit is shown. In the test card reader, a direct-current voltage output by a digital-to-analog conversion circuit is used as an input voltage Ui of a series voltage stabilizing circuit, the series voltage stabilizing circuit comprises a reference voltage circuit, a sampling circuit, a comparison amplifier and an adjusting element, wherein in the series voltage stabilizing circuit, the reference voltage circuit provides a reference voltage for the comparison amplifier, the sampling circuit takes out a part of the output voltage Uo and is connected to the input end of the comparison amplifier, the output voltage is fed back to the comparison amplifier, the voltage difference between the part of the voltage taken out by the sampling circuit and the reference voltage is amplified by the comparison amplifier and then connected to the base electrode of the adjusting element, the adjusting element amplifies the current, the adjusting element and the load are connected into an emitter output circuit form, and the current is output to the load.
In this embodiment, as shown in fig. 3, the adjusting element is a power tube, which may be a single power tube, a composite tube or a plurality of parallel power tubes. The comparison amplifier may be a single tube amplifier, a differential amplifier, or an integrated operational amplifier. The reference voltage circuit is a resistance voltage dividing circuit, in this particular embodiment, as shown in fig. 3, the resistance voltage dividing circuit includes a resistor R3 and a resistor Rz connected in series, and the sampling circuit includes a resistor R1 and a resistor R2 connected in series, in this particular embodiment, the output voltage Uo = (1 + R1/R2) Uz, so that different reference voltages are supplied to the comparison amplifier according to the voltage at the output terminal of the digital-to-analog conversion circuit, and thus, different output voltages Uo are output. In addition, when the output voltage Uo fluctuates due to the fluctuation of the current or the input voltage Ui, the circuit also plays a role in stabilizing the output voltage, thereby achieving the purpose of outputting the stable and variable output voltage. It is understood that the adjusting element, the resistor divider circuit and the sampling circuit are only examples, and other structures may be adopted, and accordingly, the expression of the output voltage Uo may be different.
Meanwhile, in order to ensure that the test card reader works safely and avoid the excessive current output by the adjusting element, an overcurrent protection circuit is further arranged, as shown in fig. 2 and fig. 3, the overcurrent protection circuit comprises a triode T2 and a resistor R5, the base of the triode T2 is connected to the current output end of the adjusting element, the current output end of the adjusting element is connected with one end of the resistor R5, the collector of the triode T2 is connected to the base of the adjusting element, and the emitter of the triode T2 is connected with the other end of the resistor R5. When the output current I does not exceed the rated current, the triode T2 is closed, when the output current I exceeds the rated current, the triode T2 is conducted, and the triode T2 is shunted from the base of the adjusting element, so that the current of the adjusting element is reduced, and the current limiting protection effect is achieved. The resistor R5 is a small resistor, and the size of the resistor R5 can be determined by the maximum output current Imax, specifically: r5= U/Imax.
In addition, the output end of the overcurrent protection circuit can be connected with a voltage sampling circuit and a first analog-to-digital conversion circuit, and the output voltage Uo of the series voltage stabilizing circuit sequentially passes through the voltage sampling circuit and the first analog-to-digital conversion (A/D) circuit and then is connected to the processor.
In addition, the output end of the overcurrent protection circuit can be connected with a current sampling circuit and a second analog-to-digital conversion circuit, and the output current of the series voltage stabilizing circuit sequentially passes through the current sampling circuit and the second analog-to-digital conversion circuit and then is connected to the processor.
Under the condition of being connected with the voltage sampling circuit, the voltage sampling circuit samples the output voltage, and the sampled voltage is transmitted to the processor after being subjected to analog-to-digital conversion. Similarly, when the current sampling circuit is connected, the current sampling circuit samples the output current, and the sampled current is subjected to analog-to-digital conversion and then transmitted to the processor.
Furthermore, a keyboard connected with the processor can be arranged, the keyboard can input the value of the voltage required to be output to the processor, the processor outputs a corresponding voltage signal to the digital-to-analog conversion circuit according to the value of the input voltage, and the required voltage is output through the series voltage stabilizing circuit.
Furthermore, a display connected with the processor can be arranged, the display can be a single display screen or a plurality of display screens and is used for displaying the magnitude of the output voltage Uo and the magnitude of the output current I0, and a user can conveniently know the magnitude of the output voltage and the magnitude of the output current at any time.
The above description is only for the preferred embodiment of the present invention, and although the present invention has been disclosed in the preferred embodiments, it is not intended to limit the present invention. The invention is not limited to the embodiments described herein, but is capable of other embodiments according to the invention, and may be used in various other applications, including, but not limited to, industrial. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical substance of the present invention all fall within the protection scope of the technical solution of the present invention.
Claims (8)
1. A test card reader is characterized by comprising a processor, a digital-to-analog conversion circuit, a series voltage stabilizing circuit and an overcurrent protection circuit; wherein,
the data output end of the processor is connected to the input end of the digital-to-analog converter and provides different input signals for the digital-to-analog conversion circuit;
the output end of the digital-to-analog conversion circuit is connected to the input end of the series voltage stabilizing circuit, and a signal output by the processor is converted into direct-current voltage;
the output end of the series voltage stabilizing circuit is connected with the input end of the overcurrent protection circuit, and the direct-current voltage output by the digital-to-analog conversion circuit is used as the input voltage of the series voltage stabilizing circuit;
the overcurrent protection circuit prevents the output current of the series voltage stabilizing circuit from exceeding the maximum allowable load value.
2. The test card reader of claim 1, wherein the series voltage regulator circuit comprises a reference voltage circuit, a sampling circuit, a comparison amplifier, and a conditioning element.
3. The test card reader of claim 2, wherein the reference voltage circuit is a resistor divider circuit, two ends of the reference voltage circuit are connected to the output end of the digital-to-analog converter, and the divided voltage of the reference voltage circuit is connected to the reference voltage end of the comparison amplifier.
4. The test card reader of claim 1, wherein the over-current protection circuit comprises a transistor and a resistor, wherein a base of the transistor is connected to a current output terminal of the adjusting element, the current output terminal of the adjusting element is connected to one end of the resistor, a collector of the transistor is connected to the base of the adjusting element, and an emitter of the transistor is connected to the other end of the resistor.
5. The test card reader of claim 1, further comprising a voltage sampling circuit and a first analog-to-digital conversion circuit, wherein the output voltage of the series voltage regulator circuit passes through the voltage sampling circuit and the first analog-to-digital conversion circuit in sequence and then is connected to the processor.
6. The test card reader of claim 1, further comprising a current sampling circuit and a second analog-to-digital conversion circuit, wherein the output current of the series voltage regulator circuit passes through the current sampling circuit and the second analog-to-digital conversion circuit in sequence and then is connected to the processor.
7. The test card reader of claim 5 or 6, further comprising a display coupled to the processor.
8. The test card reader of claim 5 or 6, further comprising a keyboard connected to the processor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720967860.1U CN207051438U (en) | 2017-08-04 | 2017-08-04 | One kind test card reader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720967860.1U CN207051438U (en) | 2017-08-04 | 2017-08-04 | One kind test card reader |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207051438U true CN207051438U (en) | 2018-02-27 |
Family
ID=61499945
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720967860.1U Active CN207051438U (en) | 2017-08-04 | 2017-08-04 | One kind test card reader |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207051438U (en) |
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2017
- 2017-08-04 CN CN201720967860.1U patent/CN207051438U/en active Active
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