Method for measuring real-time current of diode circuit and application thereof

Abstract

The application belongs to the technical field of semiconductor devices, and relates to a diode circuit real-time current measurement method and application thereof. The method is characterized in that a voltage sampling circuit is connected to both ends of the diode to be measured to collect the voltage V across the diode; a temperature sensor is used to monitor the temperature T of the diode to be measured in real time; the reverse saturation current and the ideal factor n of the diode to be measured are called from the non-volatile memory of the controller according to the voltage V and the temperature T of the diode to be measured, and the real-time current i of the diode in the actual application circuit is calculated; since the rectifier diode is a necessary element in the power supply system, the current is measured without the need for additional devices, so the circuit size can be reduced and the power supply efficiency can be improved. It has important application value in modern aviation power supply, space power supply or computing power supply, and can meet the scene demand of small size and high efficiency of the power supply.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology and relates to the testing of characteristic parameters of power devices, specifically to a method for measuring the real-time current of a diode circuit and its application. Background Technology

[0002] A rectifier diode is a semiconductor device based on the unidirectional conductivity of a PN junction, primarily used to convert alternating current (AC) to direct current (DC). Its core structure consists of P-type and N-type semiconductor materials (mostly silicon). When forward-biased, current flows from the positive terminal to the negative terminal; under reverse voltage, it blocks the current, forming a half-wave or full-wave rectification function. During operation, the rectifier diode converts all its power consumption into heat, which raises the chip temperature. Higher chip temperatures lead to less stable operation and a greater risk of damage. Therefore, it is necessary to measure the real-time current of the rectifier diode.

[0003] Currently, the existing method for measuring the real-time current of rectifier diodes involves converting the current into a voltage using a series resistor and then measuring that voltage value. The drawback is that the series resistor consumes a significant amount of energy and generates heat at high currents. Other methods often involve connecting other components in series within the circuit, which inevitably consumes energy and generates considerable heat at high currents, reducing power efficiency and failing to meet current energy-saving application requirements.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for measuring the real-time current of a diode circuit and its application, which can measure the real-time current of the rectifier diode without adding any external components.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] On one hand, this invention provides a method for measuring the real-time current of a diode circuit. This involves connecting a voltage sampling circuit across the diode under test to acquire the voltage V across the diode; using a temperature sensor to monitor the temperature T of the diode under test in real time; and retrieving the reverse saturation current of the diode under test from the controller's non-volatile memory based on the voltage V and temperature T. Using the ideality factor n, the real-time current i of the diode in the actual application circuit is calculated. The temperature sensor is placed near the diode, specifically by attaching it to the diode surface with thermally conductive adhesive to ensure the real-time performance, accuracy, and reliability of the temperature measurement.

[0008] Specifically, the formula for calculating the real-time current i of the diode is as follows:

[0009] Formula 1

[0010] In formula 1, This is the reverse saturation current, which is related to the diode material and temperature; V T For thermal voltage, V T =k×(T+273) / q,k=1.380649×10 -23 J / K, T is the measured real-time temperature of the diode, with T in °C, q = 1.6 × 10⁻⁶. -19 C; n is the ideality factor, ranging from 1 to 2, used to reflect the deviation between the actual device and the ideal model; V is the voltage across the diode.

[0011] Furthermore, the specific steps of the measurement method are as follows:

[0012] Step 1: Experimental Stage - Measure the reverse saturation current of the diode at different temperatures. and the ideal factor n;

[0013] Step 2: Measure the reverse saturation current of the diode obtained in Step 1. The ideal factor n is stored in the controller's non-volatile memory;

[0014] Step 3: Obtain the voltage V and temperature T across the diode;

[0015] Step 4: Based on the voltage V and temperature T, retrieve the reverse saturation current of the diode under test from the controller's non-volatile memory. Using the ideal factor n, the real-time current i of the diode is calculated using Formula 1.

[0016] In this method, an adjustable current source is used to power the diode, which is then placed in a temperature-controlled chamber. The operating temperature range of the diode is defined as follows: to Reverse saturation current of diodes at different temperatures The specific test steps are as follows:

[0017] Step 1.1: Adjust the temperature of the constant temperature chamber so that the diode temperature is... The current of the adjustable current source is adjusted to make the diode forward conduction and the current through the diode is increased by the same magnitude. The voltage sampling circuit is used to measure each of the at least 8 current values ​​through the diode to obtain the voltage V corresponding to the diode. The corresponding voltage data and temperature data are recorded respectively.

[0018] Step 1.2: Replace the adjustable current source with a voltage source and apply a reverse voltage to the diode. The reverse voltage is less than the minimum reverse voltage that the diode can withstand. Use an ammeter to measure the reverse saturation current of the diode at this time, and record the temperature and the reverse saturation current.

[0019] Step 1.3: Adjust the temperature of the constant temperature chamber to increase it in equal steps until... Repeat steps 1.1 and 1.2 at each temperature to obtain the diode voltage, temperature and reverse saturation current at different temperatures.

[0020] Furthermore, in step 1, the formula for calculating the ideality factor n of the diode at different temperatures during the experimental stage is as follows:

[0021] Formula 2

[0022] In Formula 2, I represents the actual diode current value measured in step 1.1 of the experimental phase. This is the reverse saturation current, which is related to the diode material and temperature; V T For thermal voltage, V T =k×(T+273) / q,k=1.380649×10 -23 J / K, T is the measured real-time temperature of the diode, with T in °C, q = 1.6 × 10⁻⁶. -19 C; V is the voltage across the diode.

[0023] Furthermore, in step 4, if the diode temperature T is between two stored adjacent temperature values... Between these, the reverse saturation current corresponding to the current temperature T is... The formulas for calculating the ideal factor n are as follows: Formula 3 and Formula 4:

[0024] Formula 3

[0025] Formula 4

[0026] In formula 3, This represents the reverse saturation current corresponding to temperature T. Indicates temperature The corresponding reverse saturation current is stored in the controller's non-volatile memory; Indicates temperature The corresponding reverse saturation current is stored in the controller's non-volatile memory; in Formula 4, n(T) represents the ideal factor corresponding to temperature T; Indicates temperature The corresponding ideal factor is stored in the controller's non-volatile memory; Indicates temperature The corresponding ideal factor is then stored in the controller's non-volatile memory. The calculated... Substituting n(T) into Formula 1, we can calculate the real-time current i of the diode in the actual application circuit.

[0027] Furthermore, in the LC rectifier circuit, the voltage sampling circuit is formed as follows: the anode of the diode is connected to the input power supply, the cathode is output through inductor L1 and capacitor C1, and is connected to the controller through the operational amplifier module and the ADC1 conversion module. The controller is also connected to the temperature sensor.

[0028] Alternatively, in the LC rectifier circuit, the voltage sampling circuit is formed as follows: the anode of the diode is connected to the input power supply, and the cathode is output through inductor L2 and capacitor C2; the anode of the diode is connected to the controller through the first resistor R1 and the ADC2 conversion module, the cathode of the diode is connected to the controller through the fourth resistor R4 and the ADC3 conversion module, the ADC2 conversion module is also grounded through the second resistor R2, and the ADC3 conversion module is also grounded through the third resistor R3; the controller is also connected to the temperature sensor.

[0029] On the other hand, the present invention also provides an application of the method for measuring the real-time current of a diode circuit as described in part or all of the above, wherein the method is used to measure the real-time current of a diode in an AC input DC output switching power supply branch.

[0030] Furthermore, the present invention also provides the application of the method for measuring the real-time current of diode circuits as described in part or all of the above in aviation power supplies, aerospace power supplies, or computing power supplies.

[0031] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0032] 1) This invention calculates the real-time current through the diode by detecting the voltage and temperature across the diode in the circuit in real time using Formula 1. Since the rectifier diode is an essential component in the power supply system, measuring the current through it does not require external devices, thus reducing the circuit size and improving power supply efficiency.

[0033] 2) Although the controller (MCU) stores the reverse saturation current corresponding to different temperatures in its non-volatile memory (FLASH), While considering the ideal factor n, since the temperature is a discrete value with equal intervals, there will inevitably be cases where the measured temperature T of the diode is not equal to the storage temperature. To avoid the influence of the above situation on the measurement results, formulas 3 and 4 are designed, and the reverse saturation current corresponding to the measured temperature T of the diode is calculated according to formula 3. The ideal factor n corresponding to the measured temperature T of the diode is calculated according to Formula 4.

[0034] In summary, the measurement method provided by this invention is simple to operate and has significant application value in modern aviation power supplies, aerospace power supplies, or computing power supplies, meeting the requirements of small power supply size and high efficiency scenarios. Attached Figure Description

[0035] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0037] Figure 1 A flowchart of the method for measuring real-time current in a diode circuit provided by the present invention;

[0038] Figure 2 The circuit diagram of the measurement method provided in Embodiment 1 of the present invention applied to the first type of LC rectifier circuit;

[0039] Figure 3 The circuit diagram for the measurement method provided in Embodiment 2 of the present invention applied in a second type of LC rectifier circuit;

[0040] Figure 4 The circuit diagram for the measurement method provided in Embodiment 3 of the present invention applied to the first AC input DC output type switching power supply branch;

[0041] Figure 5 The circuit diagram shows the application of the measurement method provided in Embodiment 4 of the present invention in the first AC input DC output type switching power supply branch. Detailed Implementation

[0042] Exemplary embodiments will now be described in detail. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0043] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] See Figure 1As shown, this invention provides a method for measuring the real-time current of a diode circuit. A voltage sampling circuit is connected across the diode under test to acquire the voltage V across the diode. A temperature sensor is used to monitor the temperature T of the diode under test in real time. Based on the voltage V and temperature T of the diode under test, the reverse saturation current of the diode under test is retrieved from the non-volatile memory of the controller. Given the ideal factor n, calculate the real-time current i of the diode in the actual application circuit.

[0045] The formula for calculating the real-time current i of the diode is as follows:

[0046] Formula 1

[0047] In Formula 1, I s This is the reverse saturation current, which is related to the diode material and temperature; V T For thermal voltage, V T =k×(T+273) / q,k=1.380649×10 -23 J / K, T is the measured real-time temperature of the diode, with T in °C, q = 1.6 × 10⁻⁶. -19 C; n is the ideality factor, ranging from 1 to 2, used to reflect the deviation between the actual device and the ideal model; V is the voltage across the diode.

[0048] Example 1

[0049] This embodiment provides a method for measuring the real-time current of a diode circuit, and the specific steps are as follows:

[0050] Step 1: Before use, measure the reverse saturation current of the diode at different temperatures during the experimental phase. and the ideal factor n;

[0051] In step 1, an adjustable current source is used to power the diode, which is then placed in a temperature-controlled chamber. The temperature is adjustable, and the operating temperature range of the diode is defined as follows: to In this embodiment, -65℃ Reverse saturation current of diodes at different temperatures, 175℃. The specific test steps are as follows:

[0052] Step 1.1: Adjust the temperature of the constant temperature chamber so that the diode temperature is... The current of the adjustable current source is adjusted to make the diode forward conduction, and the current through the diode is increased by the same magnitude and evenly distributed within the range that the diode can bear. The voltage sampling circuit is used to measure each of the eight current values ​​through the diode to obtain the voltage V corresponding to the diode. The corresponding voltage data and temperature data are recorded respectively.

[0053] Step 1.2: Replace the adjustable current source with a voltage source and apply a reverse voltage to the diode. The reverse voltage is less than the minimum reverse voltage that the diode can withstand. Use an ammeter to measure the reverse saturation current of the diode at this time, and record the temperature and the reverse saturation current.

[0054] Step 1.3: Adjust the temperature of the constant temperature chamber to increase it in equal steps until... Step length It can be adjusted according to actual needs; the setting is as follows. Repeat steps 1.1 and 1.2 at each temperature to obtain the diode voltage, temperature and reverse saturation current at different temperatures.

[0055] Furthermore, in step 1, the diode current I, voltage V, temperature T, and reverse saturation current I actually measured during the experimental phase are used. s Substitute into Formula 2 to calculate the ideal factor n. At each temperature, eight n values ​​can be obtained, and their average value is taken as the ideal factor n at that temperature.

[0056] Formula 2

[0057] In Formula 2, I represents the actual diode current value measured in step 1.1 of the experimental phase. This is the reverse saturation current, which is related to the diode material and temperature; V T For thermal voltage, V T =k×(T+273) / q,k=1.380649×10 -23 J / K, T is the measured real-time temperature of the diode, with T in °C, q = 1.6 × 10⁻⁶. -19 C; V is the voltage across the diode.

[0058] Step 2: Measure the reverse saturation current of the diode obtained in Step 1. The ideal factor n is stored in the controller's non-volatile memory. Note that the temperature here is a discrete value with equal intervals. ;

[0059] Step 3, according to Figure 2 The voltage V and temperature T across the diode are obtained using a controller; Figure 2In the LC rectifier circuit shown, the voltage sampling circuit is formed as follows: the anode of the diode is connected to the input power supply, the cathode is output through inductor L1 and capacitor C1, and is connected to the controller through the operational amplifier module and the ADC1 conversion module. The controller is also connected to the temperature sensor.

[0060] Step 4: Based on the voltage V and temperature T of each diode, retrieve the reverse saturation current of that diode from the non-volatile memory (FLASH) of the controller (MCU). Using the ideality factor n, the real-time current i through the diode is calculated using Formula 1.

[0061] It should be noted that although the controller (MCU) stores the reverse saturation current corresponding to different temperatures in its non-volatile memory (FLASH), While the ideal factor n is present, since the temperature is a discrete value with equal intervals, there will inevitably be cases where the measured temperature T of the diode and the storage temperature are not equal. Let the measured temperature T of the diode lie between two adjacent storage temperatures. Between these, the reverse saturation current corresponding to the current temperature T is... The formulas for calculating the ideal factor n are as follows: Formula 3 and Formula 4:

[0062] Formula 3

[0063] Formula 4

[0064] In formula 3, This represents the reverse saturation current corresponding to temperature T. Indicates temperature The corresponding reverse saturation current, this value is stored in the MCU's FLASH. Indicates temperature The corresponding reverse saturation current is stored in the MCU's FLASH; in Formula 4, n(T) represents the ideal factor corresponding to temperature T; Indicates temperature The corresponding ideal factor is stored in the MCU's FLASH memory; Indicates temperature The corresponding ideal factor is stored in the MCU's FLASH memory.

[0065] Example 2

[0066] Based on Example 1, this example also provides a method for measuring the real-time current of a diode circuit, the measurement principle of which is the same as that of Example 1. The difference from Example 1 lies in the formation method of the voltage sampling circuit: see [link to example]. Figure 3In the LC rectifier circuit, the anode of the diode is connected to the input power supply, and the cathode is output through inductor L2 and capacitor C2; the anode of the diode is connected to the controller through the first resistor R1 and the ADC2 conversion module, and the cathode of the diode is connected to the controller through the fourth resistor R4 and the ADC3 conversion module. The ADC2 conversion module is also grounded through the second resistor R2, and the ADC3 conversion module is also grounded through the third resistor R3; the controller is also connected to the temperature sensor.

[0067] Example 3

[0068] Based on Example 1, this example also provides the application of the above measurement method to determine the real-time current of a diode in an AC input DC output switching power supply branch. See [link to example]. Figure 4 .

[0069] Example 4

[0070] Based on Example 1, this example also provides the application of the above measurement method to determine the real-time current of a diode in an AC input DC output switching power supply branch. See [link to example]. Figure 5 .

[0071] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0072] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method of measuring the real-time current of a diode circuit, characterized in that, The voltage sampling circuit is connected across the two ends of the diode to be tested to collect the voltage V across the two ends of the diode; the temperature sensor is used to monitor the temperature T of the diode to be tested in real time; the reverse saturation current I of the diode to be tested is called from the non-volatile memory of the controller according to the voltage V and the temperature T of the diode to be tested s And the ideal factor n, the real-time current i of the diode in the practical application circuit is calculated, and the specific steps are as follows: Step 1, measuring the reverse saturation current I of the diode at different temperatures in the experimental phase s and the ideality factor n; Step 2, the reverse saturation current I of the diode measured in step 1 is measured s and the ideal factor n are stored in a non-volatile memory of the controller; Step 3, obtain the voltage V and temperature T across the diode; Step 4, according to the voltage V and temperature T, call the reverse saturation current I of the current to be tested diode in the non-volatile memory of the controller s and the ideal factor n, calculate the real-time current i of the diode; In step 1, the diode is powered by an adjustable current source, and the diode is placed in a thermostat, and the use temperature range of the diode is defined as T1 to T2, and the test steps of the reverse saturation current Is of the diode at different temperatures are as follows: Step 1.1, adjust the temperature of the thermostat to make the temperature of the diode T1, adjust the current of the adjustable current source to make the diode forward conducting, and the current through the diode increases at the same amplitude, and the voltage sampling circuit is used to measure each of at least 8 current values through the diode, to obtain the corresponding voltage V across the diode, and record the corresponding voltage data and temperature data; Step 1.2, replace the adjustable current source with a voltage source to apply a reverse voltage to the diode, and the reverse voltage is less than the minimum reverse voltage that the diode can withstand, and the reverse saturation current of the diode is measured by using an ammeter, and the temperature and reverse saturation current are recorded; Step 1.3, adjust the temperature of the thermostat to increase to T2 at equal steps, repeat steps 1.1 and 1.2 at each temperature, and obtain the voltage, temperature and reverse saturation current of the diode at different temperatures.

2. The method of claim 1, wherein the diode circuit is a diode bridge circuit. The calculation formula of the real-time current i of the diode is as follows: Formula 1 In Equation 1, I s is the reverse saturation current; V T is the thermal voltage, V T =k x (T+273) / q, k=1.380649 x 10 -23 J / K, T is the measured real-time temperature of the diode, T is in °C, q=1.6 x 10 -19 C; n is the ideal factor; V is the voltage across the diode.

3. The method of claim 1, wherein the diode circuit is a diode bridge circuit. In step 1, the calculation formula of the ideal factor n of the diode at different temperatures in the experimental stage is as follows: Formula 2 In Equation 2, I is the actual measured diode current value in step 1.1 of the experimental phase, Is the reverse saturation current; V T is the thermal voltage, V T = k x (T + 273) / q, k = 1.380649 x 10 -23 J / K, T is the real-time temperature of the measured diode, T is in °C, q = 1.6 x 10 -19 C; V is the voltage across the diode.

4. The method of claim 1, wherein the diode circuit is a diode bridge circuit. In Step 4, if the temperature T of the diode is between two adjacent temperature values stored , then the reverse saturation current , the ideal factor n corresponding to the current temperature T are calculated according to the following formulas 3, 4 respectively: Formula 3 Formula 4 In Equation 3, n(T) represents an ideal factor corresponding to temperature T. represents a reverse saturation current corresponding to temperature T. represents a reverse saturation current corresponding to temperature T. corresponding to temperature T, and is stored in a nonvolatile memory of the controller. represents a reverse saturation current corresponding to temperature T. corresponding to temperature T, and is stored in a nonvolatile memory of the controller. In Equation 4, n(T) represents an ideal factor corresponding to temperature T. represents an ideal factor corresponding to temperature T. corresponding to temperature T, and is stored in a nonvolatile memory of the controller. represents an ideal factor corresponding to temperature T. corresponding to temperature T, and is stored in a nonvolatile memory of the controller.

5. The method of claim 1, wherein the diode circuit is a diode bridge circuit. In the LC rectifier circuit, the voltage sampling circuit is formed as follows: the anode of the diode is connected with the input power supply, the cathode is output through the inductor L1 and the capacitor C1, and is connected with the controller through the operational amplifier module and the ADC1 conversion module, and the controller is also connected with the temperature sensor.

6. The method of claim 1, wherein the diode circuit is a diode bridge circuit. In the LC rectifier circuit, the voltage sampling circuit is formed as follows: the anode of the diode is connected with the input power supply, the cathode is output through the inductor L2 and the capacitor C2; the anode of the diode is connected with the controller through the first resistor R1 and the ADC2 conversion module, the cathode of the diode is connected with the controller through the fourth resistor R4 and the ADC3 conversion module, the ADC2 conversion module is grounded through the second resistor R2, and the ADC3 conversion module is grounded through the third resistor R3; the controller is also connected with the temperature sensor.

Images