Module test circuit

Abstract

The utility model provides a module test circuit, which is characterized in that a module is connected with a module power supply module of a test board through a POWER end, the module is connected with a clock module of the test board through a CLK end, the module is connected with a level conversion module of the test board through an I2C end, and the module is connected with the level conversion module of the test board through an RST end. The module is connected with the level conversion module of the test board through an SIGNAL end, and the test board is connected with a PC (Personal Computer) through an RJ45 (Registered Jack 45) or a USB (Universal Serial Bus). The utility model aims to solve the problems of high cost, complex circuit and the like of the open-short circuit test circuit of the existing module, and improves the precision of the existing test circuit.

Description

Technical Field

[0001] The utility model belongs to the technical field of circuits, and particularly relates to a module test circuit. Background Art

[0002] With the development of technology, mobile phones have become necessities in life, and there are more and more module applications, such as camera modules, fingerprint modules, photosensitive modules, etc. For module detection, the traditional method uses the method of DAC + operational amplifier + ADC to achieve closed-loop voltage output. The cost of high-precision DACs is generally high, and the cost of high-voltage and high-current operational amplifiers is also high. Therefore, there is an urgent need in this field to solve the problems of high-cost test circuits and improve the accuracy of existing detection circuits. Content of the Utility Model

[0003] The utility model provides a module test circuit, aiming at the problems of high cost and complex circuit of the existing open-circuit and short-circuit test circuits for modules, and improving the accuracy of the existing test circuit.

[0004] The utility model is realized through the following technical solutions:

[0005] A module test circuit, the circuit includes a test board, a module and a PC,

[0006] The module is connected to the module power supply module of the test board through the POWER terminal,

[0007] The module is connected to the clock module of the test board through the CLK terminal,

[0008] The module is connected to the level conversion module of the test board through the I2C terminal,

[0009] The module is connected to the level conversion module of the test board through the RST terminal,

[0010] The module is connected to the level conversion module of the test board through the SIGNAL terminal,

[0011] The test board is connected to the PC through RJ45 or USB.

[0012] Further, the test board includes an MCU, a module power supply module, a clock module, a level conversion module, a DCDC voltage stabilization module, a display screen, a programmable crystal oscillator module and a voltage regulator LDO,

[0013] The MCU is respectively connected to a low-dropout regulator (LDO), a module power supply module, a clock module, a DCDC voltage regulator module, a display screen, a programmable crystal oscillator module, and an RJ45. The LDO is connected to the DCDC voltage regulator module. The DCDC voltage regulator module is connected to the module power supply module. The programmable crystal oscillator module is connected to a level conversion module. The level conversion module, the clock module, and the module power supply module are all connected to the module.

[0014] Further, a digital potentiometer is provided between the MCU and the LDO. The digital potentiometer and the MCU transmit signals to each other through the I2C interface or the SPI communication protocol.

[0015] Further, the input ends of an operational amplifier are connected in parallel between the LDO and the module. The output end of the operational amplifier is connected to an ADC sampling module, and the ADC sampling module is connected to the MCU.

[0016] The beneficial effects of the present utility model are as follows:

[0017] The present utility model is an open / short circuit test circuit with low cost, simple circuit, and strong practicability.

[0018] Through different switch switches, the present utility model can use the same power supply for power supply, and there is no need to generate a negative voltage power supply, thus greatly reducing the production cost and simplifying the test acquisition circuit. There is no need to convert the negative voltage to a positive voltage and then collect it.

[0019] The circuit of the present utility model is simple and occupies a small space, which can greatly facilitate its application in different test circuits and make the acquisition device or the like more miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a block diagram of the present utility model.

[0021] Figure 2 is a schematic diagram of the connection position of the digital potentiometer of the present utility model on the circuit.

[0022] Figure 3 is a schematic diagram of the sampling point of the digital potentiometer of the present utility model.

[0023] Figure 4 is a schematic diagram of the positional relationship of the programmable crystal oscillator of the present utility model.

[0024] Figure 5 is a schematic diagram of the connection relationship of the level conversion module of the present utility model.

[0025] Figure 6 is a schematic diagram of the positional relationship of the AD sampling circuit of the present utility model.

[0026] Figure 7 This is the internal circuit diagram of the test board of the present utility model. Detailed implementation manners

[0027] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0028] The present utility model will be described in detail below with reference to the drawings and in combination with embodiments.

[0029] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0030] The present utility model will be described in detail below with reference to the drawings and in combination with embodiments.

[0031] This embodiment provides a module test circuit. The module test circuit includes a module, a test board, and a PC. The module is connected to the module power supply module of the test board through the POWER terminal,

[0032] the module is connected to the clock module of the test board through the CLK terminal,

[0033] the module is connected to the level conversion module of the test board through the I2C terminal,

[0034] the module is connected to the level conversion module of the test board through the RST terminal,

[0035] the module is connected to the level conversion module of the test board through the SIGNAL terminal,

[0036] the test board is connected to the PC through RJ45 or USB.

[0037] Furthermore, the test board includes an MCU, a module power supply module, a clock module, a level conversion module, a DCDC voltage regulation module, a display screen, a programmable crystal oscillator module, and a voltage regulator LDO,

[0038] the MCU is respectively connected to the voltage regulator LDO, the module power supply module, the clock module, the DCDC voltage regulation module, the display screen, the programmable crystal oscillator module, and RJ45. The voltage regulator LDO is connected to the DCDC voltage regulation module. The DCDC voltage regulation module is connected to the module power supply module. The programmable crystal oscillator module is connected to the level conversion module. The level conversion module, the clock module, and the module power supply module are all connected to the module.

[0039] The MCU sends relevant instructions through RST and I2C to initialize the module and set parameters; and can obtain information such as the shutter and the synchronization signal through the signal signal.

[0040] Further, a digital potentiometer is provided between the MCU and the voltage regulator LDO, and the digital potentiometer and the MCU transmit signals to each other through the I2C interface or the SPI communication protocol.

[0041] Further, the input end of an operational amplifier is connected in parallel between the voltage regulator LDO and the module, the output end of the operational amplifier is connected to the ADC sampling module, and the ADC sampling module is connected to the MCU.

[0042] Specifically, ① is a digital potentiometer, adopting AD5272BRMZ of ADI manufacturer;

[0043] ② is an LDO, adopting TPS7A7002DDAR of TI manufacturer. The MCU sends signals to the digital potentiometer through SPI. After receiving the MCU information, the digital potentiometer switches to resistors with different resistance values to obtain different voltages;

[0044] ⑤ adopts a TFT screen for displaying information such as addresses;

[0045] ⑥ communicates with the PC through a network port. The MCU adopts an internal RMII, connects to HR911105A through LAN8720, and then communicates with the PC;

[0046] ⑦ adopts AP64350SP-13. The input power supply of the test board is 12V / 2A. The maximum input voltage of AP64350SP-13 can be as high as 40V. It converts the 12V voltage into 5V for the module LDO and the internal power supply of the test board;

[0047] ⑧ adopts AMS1117 to convert 5V into 3.3V to supply power to the chip;

[0048] ⑨ adopts STM32F767ZGT6, which supports DSP functions and a powerful floating-point arithmetic unit.

[0049] The specific working principle is that the MCU adjusts the voltage output and detects the current through ADC sampling. When the current exceeds the threshold, it indicates that the module has an abnormality and actively performs power-off protection.

[0050] Further, a voltage sampling point and a resistance sampling point are also provided between the voltage regulator LDO and the digital potentiometer in the test board; for the resistance sampling point, a grounding resistor needs to be connected when sampling the resistance value.

[0051] Further, when the digital potentiometer is to output a 5V voltage, the voltage sampling point is the FB pin of the LDO, the voltage is 0.5V, a 10-bit digital potentiometer is adopted, the resistance value is 5.55K, and the total range of the digital potentiometer is 50K at this time. The calculation method is as follows:

[0052] 0.5 * ((50 * D / 1024) + 5.55) / 5.55

[0053] Among them, D is the set value of the digital potentiometer. It is obtained that the maximum output voltage of the digital potentiometer is 5.004V, the minimum output voltage is 0.5044V, and the minimum resolution is less than 5mV. Thus, a voltage accuracy with a step of 10mV can be obtained by adjusting the specification parameters of the resistor.

[0054] Specifically, the traditional DAC scheme also uses 10 bits, and its resolution is calculated as follows: 5V / 1024 = 0.0048V.

[0055] The closed-loop voltage output is realized by using the digital potentiometer + LDO + ADC, and the resolution can reach 0.0044V.

[0056] In the case of achieving the same resolution, the overall cost of the DAC + operational amplifier + ADC detection closed-loop scheme is much higher than that of the digital potentiometer + LDO + ADC scheme.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A module test circuit, characterized in that: The circuit includes a test board, a module and a PC. The module is connected to the module power module of the test board through the POWER terminal. The module is connected to the clock module of the test board via the CLK terminal. The module is connected to the level conversion module of the test board through the I2C terminal. The module is connected to the level conversion module of the test board through the RST terminal. The module is connected to the level conversion module of the test board through the SIGNAL terminal. The test board is connected to the PC via RJ45 or USB.

2. A module test circuit according to claim 1, characterized in that: The test board includes an MCU, a module power module, a clock module, a level conversion module, a DCDC voltage regulator module, a display screen, a programmable crystal oscillator module and a voltage regulator LDO; The MCU is respectively connected to the voltage regulator LDO, the module power module, the clock module, the DCDC voltage regulator module, the display screen, the programmable crystal oscillator module and the RJ45; the voltage regulator LDO is connected to the DCDC voltage regulator module, the DCDC voltage regulator module is connected to the module power module, the programmable crystal oscillator module is connected to the level conversion module, and the level conversion module, the clock module and the module power module are all connected to the module.

3. A module test circuit according to claim 2, characterized in that: A digital potentiometer is arranged between the MCU and the voltage stabilizer LDO, and the digital potentiometer and the MCU transmit signals to each other through an I2C terminal or an SPI communication protocol.

4. A module test circuit according to claim 3, characterized in that: The voltage regulator LDO is connected in parallel with the input end of the operational amplifier between the module, the output end of the operational amplifier is connected to the ADC sampling module, and the ADC sampling module is connected to the MCU.

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