A system for measuring the time response of a phototransistor

Abstract

The utility model discloses a kind of time response measurement systems of photoelectric transistor, comprising: MCU measurement module is connected with constant current source by DAC module one;MCU measurement module is connected with constant voltage source by DAC module two, one end of test photoelectric transistor is connected with constant voltage source output end, the other end of test photoelectric transistor is grounded through load RL, its connecting node is connected with the positive phase input end of operational amplifier, the output end of operational amplifier is connected with the output end of operational amplifier, the output end of operational amplifier is connected with MCU measurement module through several groups of comparator;The positive phase input end of each group of comparator is connected with the output end of operational amplifier, for obtaining test source;The inverting input end of each group of comparator is connected with MCU measurement module, for obtaining reference source.The utility model discloses a kind of time response measurement systems of photoelectric transistor, reduces test threshold, improves the economic convenience of test.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor testing technology, specifically to a time response measurement system for phototransistors. Background Technology

[0002] In recent years, with industrial upgrading, my country's high-end manufacturing industry has achieved rapid development. Whether in the home appliance field or the automotive field, optotransistors are an indispensable device.

[0003] Time response is a crucial step in the reliability assessment of phototransistors, and a time response measurement system plays a vital role in controlling for defective phototransistor materials. By testing the time response, it is possible to evaluate whether the performance of the phototransistor meets design requirements, identify potential problems, and thus take corresponding improvement measures. Commercially available testing equipment is generally expensive; therefore, there is an urgent need for the rapid deployment of more cost-effective testing equipment that ensures both accuracy and stability. Utility Model Content

[0004] This invention overcomes the shortcomings of the prior art and provides a time response measurement system for phototransistors, which lowers the testing threshold and improves the economic convenience of testing.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a time response measurement system for phototransistors, comprising: an MCU measurement module, wherein the MCU measurement module is connected to a constant current source through a DAC module to provide test power to the test light source module; The MCU measurement module is also connected to a constant voltage source through DAC module 2 to provide test power to the test phototransistor. One end of the test phototransistor is connected to the output terminal of the constant voltage source, and the other end of the test phototransistor is grounded through the load RL. The connection node between the test phototransistor and the load RL is connected to the non-inverting input terminal of the operational amplifier, the inverting input terminal of the operational amplifier is connected to the output terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the MCU measurement module through several sets of comparators. The non-inverting input of each comparator is connected to the output of the operational amplifier to obtain the test source; the inverting input of each comparator is connected to the MCU measurement module to obtain the reference source.

[0006] In a preferred embodiment of this utility model, the plurality of comparators include comparator one and comparator two, wherein the non-inverting input terminal of comparator one and the non-inverting input terminal of comparator two are connected at the same point to the output terminal of the operational amplifier. The inverting input of comparator one is connected to the MCU measurement module through DAC module three to obtain reference source one; The inverting input of comparator two is connected to the MCU measurement module through DAC module four to obtain reference source two.

[0007] In a preferred embodiment of this invention, the photosensitive side of the test phototransistor corresponds to the light-emitting side of the test light source module; the emitter of the test phototransistor is grounded through the load RL and a COM2 node is led out; the input terminal of the test phototransistor is connected to the output terminal of the constant voltage source and a HOT2 node is led out.

[0008] In a preferred embodiment of this invention, the output terminal of the operational amplifier is also grounded through an adjustment capacitor.

[0009] In a preferred embodiment of this invention, the inverting input terminal of the operational amplifier is connected to the output terminal of the operational amplifier via a filter.

[0010] In a preferred embodiment of this utility model, the non-inverting input terminal of comparator one is connected to the output terminal of the operational amplifier through resistor R2, the output terminal of comparator one is connected to the MCU measurement module through resistor R3, and the inverting input terminal of comparator one is connected to DAC module three through resistor R1. The non-inverting input of comparator two is connected to the output of the operational amplifier through resistor R5, the output of comparator two is connected to the MCU measurement module through resistor R6, and the inverting input of comparator two is connected to DAC module four through resistor R4.

[0011] In a preferred embodiment of this utility model, the filter uses resistor R7. The inverting input terminal of the operational amplifier is connected to the output terminal of the operational amplifier through resistor R7. The inverting input terminal of the operational amplifier is also grounded through resistor R8. The non-inverting input terminal of the operational amplifier is also connected to the COM2 node through resistor R9.

[0012] In a preferred embodiment of this utility model, the input terminal of the constant current source is connected to the MCU measurement module, the non-inverting terminal of the test light source module is connected to the output terminal of the constant current source, and the inverting terminal of the test light source module is grounded; and the non-inverting terminal of the test light source module is led out to the HOT1 node, and the inverting terminal of the test light source module is led out to the COM1 node.

[0013] This utility model solves the defects existing in the technical background, and the beneficial technical effects of this utility model are: This invention provides a time response measurement system for phototransistors, which lowers the testing threshold and improves the cost-effectiveness and convenience of testing. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1This is an overall framework diagram of a time response measurement system for a phototransistor according to a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the test waveform of a time response measurement system for a phototransistor according to a preferred embodiment of the present invention; Figure 3 This is a circuit diagram of a comparator circuit for a time response measurement system of a phototransistor according to a preferred embodiment of the present invention. Figure 4 This is a circuit diagram of the amplifier circuit of a time response measurement system for a phototransistor according to a preferred embodiment of the present invention. Figure 5 This is a test interface diagram of a time response measurement system for a phototransistor according to a preferred embodiment of the present invention; Figure 6 It is the tr value (rise time) measured using the oscilloscope test mode in existing technology (CH1 channel is the light source waveform, CH2 channel is the transistor response waveform). Figure 7 It is the tf value measured using the oscilloscope test mode in existing technology (CH1 channel is the light source waveform, and CH2 channel is the transistor response waveform). Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0017] It should be noted that if directional indicators (such as up, down, bottom, top, etc.) are involved in the embodiments of this utility model, the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0018] Example 1, as Figure 1As shown, a time response measurement system for a phototransistor includes: an MCU measurement module, which is connected to a constant current source via a DAC module to provide test power to a test light source module; the input terminal of the constant current source is connected to the MCU measurement module, the non-inverting terminal of the test light source module is connected to the output terminal of the constant current source, and the inverting terminal of the test light source module is grounded; and the non-inverting terminal of the test light source module is connected to a HOT1 node, and the inverting terminal of the test light source module is connected to a COM1 node.

[0019] Specifically, the MCU measurement module also provides test power to the test phototransistor via a constant voltage source connected to DAC module 2. One end of the test phototransistor is connected to the output of the constant voltage source, and the other end is grounded through the load RL. The connection node between the test phototransistor and the load RL is connected to the non-inverting input of the operational amplifier, and the inverting input of the operational amplifier is connected to its output. The output of the operational amplifier is connected to the MCU measurement module through several sets of comparators. The photosensitive side of the test phototransistor corresponds to the light-emitting side of the test light source module. The emitter of the test phototransistor is grounded through the load RL and a COM2 node is led out. The input of the test phototransistor is connected to the output of the constant voltage source and a HOT2 node is led out. The output of the operational amplifier is also grounded through an adjustment capacitor. The inverting input of the operational amplifier is connected to its output through a filter.

[0020] Specifically, the non-inverting input of each comparator is connected to the output of an operational amplifier to acquire a test source; the inverting input of each comparator is connected to the MCU measurement module to acquire a reference source. Further, the comparators include Comparator 1 and Comparator 2, with the non-inverting inputs of Comparator 1 and Comparator 2 sharing a common point connected to the output of the operational amplifier; the inverting input of Comparator 1 is connected to the MCU measurement module via DAC module 3 to acquire reference source 1; the inverting input of Comparator 2 is connected to the MCU measurement module via DAC module 4 to acquire reference source 2.

[0021] Example 2, based on Example 1, such as Figure 1 As shown, a time response measurement system for a phototransistor includes: an MCU measurement module, which is connected to a constant current source via a DAC module to provide test power to a test light source module; the input terminal of the constant current source is connected to the MCU measurement module, the non-inverting terminal of the test light source module is connected to the output terminal of the constant current source, and the inverting terminal of the test light source module is grounded; and the non-inverting terminal of the test light source module is connected to a HOT1 node, and the inverting terminal of the test light source module is connected to a COM1 node.

[0022] Specifically, the MCU measurement module also provides test power to the test phototransistor via a constant voltage source connected to DAC module 2. One end of the test phototransistor is connected to the output of the constant voltage source, and the other end is grounded through the load RL. The connection node between the test phototransistor and the load RL is connected to the non-inverting input of the operational amplifier, and the inverting input of the operational amplifier is connected to its output. The output of the operational amplifier is connected to the MCU measurement module through several sets of comparators. The photosensitive side of the test phototransistor corresponds to the light-emitting side of the test light source module. The emitter of the test phototransistor is grounded through the load RL and a COM2 node is led out. The input of the test phototransistor is connected to the output of the constant voltage source and a HOT2 node is led out. The output of the operational amplifier is also grounded through an adjustment capacitor. The inverting input of the operational amplifier is connected to its output through a filter. Furthermore, in this embodiment, the filter uses resistor R7. The inverting input of the operational amplifier is connected to the output of the operational amplifier (i.e., the voltage acquisition node) through resistor R7. The inverting input of the operational amplifier is also grounded through resistor R8. Furthermore, the output of the operational amplifier is connected to the non-inverting inputs of comparator one and comparator two, as well as one end of the adjustment capacitor. The non-inverting input of the operational amplifier is also connected to the COM2 node through resistor R9. The COM2 port is connected to resistor R9, resistor RL, and the emitter of the material under test.

[0023] Specifically, the non-inverting input of each comparator is connected to the output of an operational amplifier to acquire a test source; the inverting input of each comparator is connected to the MCU measurement module to acquire a reference source. Further, the comparators include Comparator 1 and Comparator 2, with the non-inverting inputs of Comparator 1 and Comparator 2 sharing a common point connected to the output of the operational amplifier; the inverting input of Comparator 1 is connected to the MCU measurement module via DAC module 3 to acquire reference source 1; the inverting input of Comparator 2 is connected to the MCU measurement module via DAC module 4 to acquire reference source 2. Furthermore, in this embodiment, the non-inverting input of comparator one is connected to the output of the operational amplifier through resistor R2, the output of comparator one is connected to the MCU measurement module through resistor R3, and the inverting input of comparator one is connected to DAC module three through resistor R1; the non-inverting input of comparator two is connected to the output of the operational amplifier through resistor R5, the output of comparator two is connected to the MCU measurement module through resistor R6, and the inverting input of comparator two is connected to DAC module four through resistor R4.

[0024] In this embodiment, the MCU chip used in the MCU measurement module is an STC12C5A60S2 MCU chip. DAC modules one, two, three, and four each use an AD5754RBREZ-REEL7 chip, and the comparator chip is an LT1715CMS#PBF. The amplifier used is an ADA4610-2ARMZ amplifier, the constant current source is an OPA2277UA chip, and the constant voltage source is an OPA132UA chip. The circuit diagram of the operational amplifier circuit is shown below. Figure 4 As shown, the "filter" in this circuit is R7.

[0025] Figure 5 This embodiment compares the time response test value of one of the products in the prior art with the test value measured by an oscilloscope using the same material. Figure 6 In the middle, tr represents the rise time. Figure 7 In the middle, tf represents the descent time.

[0026] This embodiment discloses a time response measurement system for phototransistors, which lowers the testing threshold and improves the cost-effectiveness and convenience of testing.

[0027] Example 3 is a measurement method for a time response measurement system of a phototransistor, based on Example 2. The test principle and measurement method implemented include the following: The MCU measurement module is used to send control commands to various modules.

[0028] The MCU measurement module sends power-on parameters to DAC module one. DAC module one converts the digital signal to an analog signal and outputs it to a constant current source. The constant current source outputs the constant current set by the MCU measurement module to illuminate the light source. The MCU measurement module then sends power-on parameters to DAC module two. DAC module two converts the digital signal to an analog signal and outputs it to a constant voltage source. The constant voltage source outputs the constant voltage VCC set by the MCU measurement module to the collector (C) terminal of the test phototransistor (phototransistor) relative to ground. The voltage between the collector (C) and emitter (E) terminals of the test phototransistor is VCE. The voltage between the COM2 port and ground is VRL, where VRL = VCC - VCE. VRL, detected by the non-inverting input of the operational amplifier, is connected to the output of the operational amplifier to an adjustable capacitor, the non-inverting input of comparator two, and the non-inverting input of comparator two. The MCU measurement module then sends power-on parameters to DAC module three. DAC module three converts the digital signal to an analog signal, which becomes reference source one, and outputs it to the inverting input of comparator one. The MCU measurement module sends power-on parameters to DAC module four. DAC module four converts the digital signal to an analog signal, which becomes reference source two, and outputs it to the inverting input of comparator two. Reference source one at the inverting input of comparator one is set to 10% of VRL. It is compared with the voltage sampled at the non-inverting input of comparator one. If the sampled voltage is greater than reference source one, comparator one outputs a high level. Reference source two at the inverting input of comparator two is set to 90% of VRL. It is compared with the voltage sampled at the non-inverting input of comparator two. If the sampled voltage is greater than reference source two, comparator two outputs a high level. The MCU measurement module starts timing when comparator one outputs from low to high, and ends timing when comparator two outputs from low to high. The measured time is the rise time of the phototransistor. When comparator 2 outputs a high level and then a low level, the MCU measurement module starts timing. When comparator 1 outputs a high level and then a low level, the MCU measurement module stops timing. The measured time is the rise time (Fall Time) of the phototransistor. The test waveform is as follows: Figure 2 As shown.

[0029] Specifically, such as Figure 3 The detailed comparator circuit is shown. Reference source 1 is connected to the IN- port of comparator 1 through impedance matching resistor R1. The sampled voltages are connected to the IN+ ports of comparator 1 and comparator 2 through impedance matching resistors R2 and R5, respectively. Reference source 2 is connected to the IN- port of comparator 2 through impedance matching resistor R2. The output of comparator 1 is connected to the MCU through impedance matching resistor R3, and the output of comparator 2 is connected to the MCU through impedance matching resistor R6.

[0030] This utility model discloses a time response measurement system for phototransistors; it has a greater cost advantage than current production line equipment, greatly alleviates the cost pressure on packaging plants, lowers the testing threshold, and promotes the rapid development of the phototransistor industry.

[0031] The above specific embodiments are specific support for the proposed solution concept of this utility model, and should not be used to limit the protection scope of this utility model. Any equivalent changes or modifications made on the basis of this technical solution in accordance with the technical concept proposed by this utility model shall still fall within the protection scope of this utility model.

Claims

1. A time response measurement system for a phototransistor, characterized in that, include: The MCU measurement module is connected to a constant current source via a DAC module to provide test power to the test light source module. The MCU measurement module is also connected to a constant voltage source through DAC module 2 to provide test power to the test phototransistor. One end of the test phototransistor is connected to the output terminal of the constant voltage source, and the other end of the test phototransistor is grounded through the load RL. The connection node between the test phototransistor and the load RL is connected to the non-inverting input terminal of the operational amplifier, the inverting input terminal of the operational amplifier is connected to the output terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the MCU measurement module through several sets of comparators. The non-inverting input of each comparator is connected to the output of the operational amplifier to obtain the test source; the inverting input of each comparator is connected to the MCU measurement module to obtain the reference source.

2. The time response measurement system for a phototransistor according to claim 1, characterized in that: Several sets of comparators include comparator one and comparator two, wherein the non-inverting input terminal of comparator one and the non-inverting input terminal of comparator two are connected at the same point to the output terminal of the operational amplifier; The inverting input of comparator one is connected to the MCU measurement module through DAC module three to obtain reference source one; The inverting input of comparator two is connected to the MCU measurement module through DAC module four to obtain reference source two.

3. The time response measurement system for a phototransistor according to claim 2, characterized in that: The photosensitive side of the test phototransistor corresponds to the light-emitting side of the test light source module; the emitter of the test phototransistor is grounded through the load RL and brought out to the COM2 node; the input terminal of the test phototransistor is connected to the output terminal of the constant voltage source and brought out to the HOT2 node.

4. The time response measurement system for a phototransistor according to claim 3, characterized in that: The output of the operational amplifier is also grounded via an adjustment capacitor.

5. The time response measurement system for a phototransistor according to claim 4, characterized in that: The inverting input of the operational amplifier is connected to the output of the operational amplifier via a filter.

6. The time response measurement system for a phototransistor according to claim 5, characterized in that: The non-inverting input terminal of comparator one is connected to the output terminal of the operational amplifier through resistor R2, the output terminal of comparator one is connected to the MCU measurement module through resistor R3, and the inverting input terminal of comparator one is connected to DAC module three through resistor R1. The non-inverting input of comparator two is connected to the output of the operational amplifier through resistor R5, the output of comparator two is connected to the MCU measurement module through resistor R6, and the inverting input of comparator two is connected to DAC module four through resistor R4.

7. The time response measurement system for a phototransistor according to claim 6, characterized in that: The filter uses resistor R7. The inverting input of the operational amplifier is connected to the output of the operational amplifier through resistor R7. The inverting input of the operational amplifier is also grounded through resistor R8. The non-inverting input of the operational amplifier is also connected to the COM2 node through resistor R9.

8. The time response measurement system for a phototransistor according to claim 7, characterized in that: The input terminal of the constant current source is connected to the MCU measurement module, the non-inverting terminal of the test light source module is connected to the output terminal of the constant current source, and the inverting terminal of the test light source module is grounded; and the non-inverting terminal of the test light source module is led out to the HOT1 node, and the inverting terminal of the test light source module is led out to the COM1 node.

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