Wide-range high-precision IV conversion circuit and method for real-time monitoring of power transmission

Abstract

The invention provides a wide-range high-precision IV conversion circuit and method for real-time monitoring of power transmission. The wide-range high-precision IV conversion circuit comprises a power transmission circuit, a current detection circuit, a reference voltage generation circuit, a dual-comparator circuit, a Desound circuit, an interval selection circuit, a software configuration selection circuit and a decoding circuit. Wherein the reference voltage generation circuit is used for selecting two of M reference voltages and outputting the selected reference voltages to the dual-comparator circuit, the dual-comparator circuit is used for comparing a detection voltage with a first comparison threshold voltage and a second comparison threshold voltage, and the interval selection circuit is used for switching intervals according to a comparison result, the interval selection circuit is gradually switched to the optimal interval to which the detection current of the controllable transmission power tube belongs through the feedback loop, so that the controllable transmission power tube is adjusted to reach the optimal current mirror image proportion, and the current detection with high precision, wide range and real-time performance of power transmission is realized; the chip area is optimized; and the effect of mistakenly selecting gears is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit design, and in particular to a wide-range high-precision IV conversion circuit and method for real-time monitoring of power transmission. Background Art

[0002] The IV conversion circuit is used to convert current signals into voltage signals for measurement and processing. It is widely used in electronic measurement, control systems, signal detection and other scenarios. At present, in the application of power transmission chips, most of them need to design IV conversion circuits to realize wide-range and high-precision current detection while power transmission, so as to monitor and adjust the transmission power in real time to achieve real-time protection of the chip. In the design of IV conversion circuits, the factors considered mainly include conversion speed, conversion accuracy and conversion range. Among them, the conversion speed can be achieved by increasing the bandwidth of circuits such as OP, but there is a problem of mutual restriction between conversion accuracy and conversion range. There are two solutions to this problem:

[0003] (1) The output voltage is monitored by using an ADC or other monitoring circuit, and the mirror image ratio is adjusted by software to achieve the accuracy of the mirror image, so as to ensure the accuracy of current-voltage conversion. Figure 1 , two PMOS tubes MP1 and MP2 are used to transfer power from the VIN end to the VOUT end, and a PMOS tube MP3 is used as a mirror tube of the MP1 and MP2 power tubes to detect the current in the power tube. The voltages of the VA node and the VB node are clamped by the op amp 101 and the PMOS tube MP4 to ensure the accuracy of the current detection. Finally, the detection current of the MP3 tube is converted into a voltage through the resistor XR1 to achieve IV conversion. It can be seen that although this scheme can select the gate connection mode of the MP2 tube through the external control switch state of the software to achieve the change of the mirror ratio of the power tube current, this circuit cannot adjust the mirror ratio autonomously. At the same time, since it also relies on an external monitoring circuit for output voltage monitoring, such as an ADC circuit, it will also make the entire IV conversion time too long, thereby increasing the current detection response time of the circuit, and failing to achieve effective real-time monitoring of the transmission power. Especially in applications where the power tube current needs to be monitored to achieve overcurrent protection, untimely response may cause serious problems such as chip burning.

[0004] (2) By using multiple comparators to compare the voltage converted from the current with different reference voltages, the target range is found and then the corresponding control signal is generated according to the range to adjust the mirror ratio. Figure 2 The control module uses a comparator array module 2021 composed of M comparators, and the comparator array module 2021 inputs M different reference voltages VREF respectively. <m:1>The output voltage VSENS of the current detection module is compared with M different reference voltages VREF, and M comparison results are generated and output to the decoding circuit. The decoding circuit converts the M comparison results into N-bit binary codes to generate a control signal. The current detection module generates a control signal based on the control signal SWEN <m:1>The number of power tubes in the switch module is adjusted, and the output voltage point of the voltage divider resistor in the voltage generation module 2013 is adjusted, so as to achieve real-time adjustment of the mirror ratio. It can be seen that this solution can support high-precision, wide-range and real-time current detection, but its disadvantages are also obvious. In order to pursue high precision, more control gears are required, which requires more comparators to be added to the comparator array module 2021. The use of a large number of comparators will consume a lot of chip area, which is not conducive to the miniaturization design of the chip. In addition, if this solution is applied to the adjustment of a large span of gears, the wrong gear may be selected due to IV conversion accuracy problems.

[0005] Therefore, considering the problems existing in the above two solutions, there is a need for an IV conversion circuit and method that can achieve high-precision, wide-range and real-time current detection, optimize chip area and avoid wrong gear selection. Summary of the invention

[0006] The wide-range high-precision IV conversion circuit and method for real-time monitoring of power transmission provided by the present invention are mainly used to solve the problems of existing IV conversion schemes that cannot independently adjust the mirror ratio, the conversion time is too long, the chip area is large, and the gear is selected incorrectly, thereby achieving the effect of optimizing the chip area and avoiding the wrong gear selection while realizing high-precision, wide-range and real-time current detection of power transmission.

[0007] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0008] A wide range high precision IV conversion circuit for real-time monitoring of power transmission, comprising a power transmission circuit, a current detection circuit and a control circuit, wherein the power transmission circuit comprises a plurality of transmission power tubes for power transmission, the current detection circuit and the transmission power tube constitute a current mirror circuit, which is used to detect the current when the transmission power tube is turned on and convert it into a detection voltage and output it to the control circuit, wherein the control circuit comprises:

[0009] A reference voltage generating circuit, a dual comparator circuit and an interval selection circuit, wherein the reference voltage generating circuit is provided with M reference voltages of different sizes, and is used to select two of the reference voltages as a first comparison threshold voltage and a second comparison threshold voltage and output them to the dual comparator circuit respectively, the dual comparator circuit inputs the detection voltage, and is used to compare the detection voltage with the first comparison threshold voltage and the second comparison threshold voltage respectively, and output the comparison result to the interval selection circuit, and the interval selection circuit is provided with M+1 different intervals according to the current detection range when the controllable transmission power tube is turned on, and the thresholds of the M+1 different intervals are respectively the same as the thresholds of the M+1 different intervals. The reference voltages correspond one to one, the interval selection circuit is used to switch the interval according to the comparison result, and output the first control signal and the second control signal to the reference voltage generating circuit and the power transmission circuit respectively to form a feedback loop, the reference voltage generating circuit is used to reselect the corresponding two reference voltage outputs according to the first control signal, the power transmission circuit is used to adjust the conduction quantity of the controllable transmission power tube according to the second control signal, and the interval selection circuit gradually switches to the optimal interval to which the controllable transmission power tube detection current belongs through the feedback loop, thereby adjusting the controllable transmission power tube to achieve the optimal current mirror ratio.

[0010] A further solution is that the power transmission circuit includes a first MOS tube, several switches and M controllable transmission power tubes, the gate of the first MOS tube is connected to the first voltage, the source thereof is connected to the second voltage, and the drain is connected to the voltage output end; the M controllable transmission power tubes are respectively connected in parallel with the first MOS tube, and their gates are respectively connected to the first voltage or the second voltage through several of the switches.

[0011] A further solution is that the current detection circuit includes a second MOS tube, a clamping circuit and a voltage output circuit, the gate of the second MOS tube is connected to the first voltage, the source thereof is connected to the second voltage, and the drain thereof is connected to the first input end of the clamping circuit; the second input end of the clamping circuit is connected to the voltage output end of the power transmission circuit, and is used to clamp the drain-source voltage of the controllable transmission power tube and the drain-source voltage of the second MOS tube to equal sizes, and output the detection current; the voltage output circuit adopts a voltage divider resistor array, and is used to select different voltage output gears according to the second control signal to convert the detection current into the detection voltage output of different sizes.

[0012] A further solution is that the ratio of the detection current to the current at the voltage output end of the power transmission circuit is:

[0013]

[0014] in, is the (W / L) size of the second MOS tube, that is, the ratio of the width to the length of the conductive channel, It is the sum of the (W / L) sizes of the first MOS tube and the MOS tube in the on state among the M controllable transmission power tubes.

[0015] A further solution is that the voltage output circuit further includes a calibrable resistor, which is connected to the output end of the clamping circuit and is used to calibrate the calibrable resistor through a register to ensure that the IV conversion scale factor remains constant; the IV conversion scale factor is:

[0016]

[0017] Among them, V SENS is the detection voltage, R DET is the resistance value of the calibrable resistor, and K is:

[0018]

[0019] Among them, I SENS is the detection current, V RES is the terminal voltage of the calibrable resistor.

[0020] A further solution is that the comparison logic of the dual comparator circuit is: when the detection voltage is greater than the first comparison threshold voltage or the second comparison threshold voltage, the comparison result is output as 1, and when it is less than 0, the comparison result is output as 0.

[0021] Then the comparison result output by the dual comparator circuit is:

[0022] When the detection voltage is greater than both the first comparison threshold voltage and the second comparison threshold voltage, the comparison result is output as 11.

[0023] When the detection voltage is both smaller than the first comparison threshold voltage and the second comparison threshold voltage, the comparison result is output as 00.

[0024] When the detection voltage is between the first comparison threshold voltage and the second comparison threshold voltage, the comparison result is output as 01.

[0025] A further solution is that the interval selection circuit uses an N-bit binary number to represent M+1 different intervals, and the Mth interval is represented by a binary number DRV <n-1>:M=2 N -1.

[0026] If the binary number DRV <n-1>The larger the value, the larger the current detection value corresponding to the interval. The interval switching logic is:

[0027] The condition that the current interval is the optimal interval is: the comparison result is 11, the binary number DRV <n-1>is all 1; or the comparison result is 00, the binary number DRV <n-1>is all 0; or the comparison result is 01.

[0028] When the comparison result is 11, the binary number DRV <n-1>When it is not all 1, the binary number DRV <n-1>Add 1 to move up one range.

[0029] When the comparison result is 00, the binary number DRV <n-1>When it is not all 0, the binary number DRV <n-1>Subtract 1, which means moving down one range.

[0030] A further solution is to further include a software configuration selection circuit, which is connected to the output end of the interval selection circuit and is used to provide a software configuration value and select an output between the binary number and the software configuration value.

[0031] A further solution is to further include a decoding circuit, which uses thermometer decoding to convert the binary number or software configuration value into a thermometer code as the second control signal output, and the thermometer code includes M+1 different values. The larger the value, the more the number of controllable transmission power tubes that are turned on and the larger the voltage division ratio of the voltage divider resistor array.

[0032] A wide range high precision IV conversion method for real-time monitoring of power transmission is applied to the wide range high precision IV conversion circuit for real-time monitoring of power transmission, comprising:

[0033] S1: The power transmission circuit transmits power through the first MOS tube and M controllable transmission power tubes, and the reference voltage generation circuit selects two initial reference voltage outputs.

[0034] S2: The current detection circuit detects the conduction current of the first MOS tube and the controllable transmission power tube and converts it into a detection voltage output; the dual comparison circuit compares the detection voltage with the two reference voltages respectively and outputs the comparison result.

[0035] S3: The interval selection circuit determines whether the current interval is the optimal interval according to the comparison result, and if so, maintains the interval; if not, switches the interval and outputs the first control signal and the second control signal.

[0036] S4: The reference voltage generating circuit reselects the corresponding two reference voltage outputs according to the first control signal, and the power transmission circuit adjusts the conduction number of the controllable transmission power tubes and the voltage dividing ratio of the voltage dividing resistor array according to the second control signal, and returns to execute step S2.

[0037] It can be seen that the present invention has the following beneficial effects:

[0038] 1. The present invention compares and judges the detection voltage, outputs a control signal to adjust the reference voltage generating circuit to select the output of two reference voltages and the number of power tubes that are turned on, and gradually reaches the optimal interval using a feedback control loop. Compared with the traditional software external control switch state to adjust the mirror ratio or the use of multiple comparators, the present invention can independently adjust the mirror ratio, and only needs to use a dual comparator circuit to realize the step-by-step comparison of the detection voltage with multiple reference voltages, which greatly optimizes the chip area, reduces the hardware consumption of chip design, and reduces costs.

[0039] 2. The present invention divides the detection current range into multiple current intervals, and gradually switches to the optimal interval through a step-by-step interval switching method, which can avoid the situation of selecting the wrong gear during switching.

[0040] 3. The present invention can set the interval size according to actual needs, thereby realizing more precise automatic adjustment of the mirror ratio and the output voltage division ratio, and at the same time can achieve high current-voltage conversion accuracy in a wide current transmission range.

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the IV conversion circuit of the prior art solution (1).

[0043] Figure 2 It is a schematic diagram of the IV conversion circuit of the prior art solution (2).

[0044] Figure 3 Schematic diagram of a wide range high precision IV conversion circuit according to an embodiment of the present invention.

[0045] Figure 4 It is a schematic diagram of a power transmission circuit and a current detection circuit according to an embodiment of the present invention.

[0046] Figure 5 Schematic diagram of a reference voltage generating circuit and a dual comparator circuit according to an embodiment of the present invention

[0047] Figure 6 4 is a schematic diagram of a Debounce circuit according to an embodiment of the present invention.

[0048] Figure 7 It is a schematic diagram of a software configuration selection circuit according to an embodiment of the present invention.

[0049] Figure 8 It is a flow chart of a wide range and high precision IV conversion method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Wide range high precision IV conversion circuit embodiment for real-time monitoring of power transmission

[0052] See also Figure 3 The embodiment of the present invention involves a wide-range high-precision IV conversion circuit for real-time monitoring of power transmission, including a power transmission circuit 10, a current detection circuit 20 and a control circuit. The power transmission circuit 10 includes a plurality of transmission power tubes for power transmission. The current detection circuit 20 and the transmission power tube constitute a current mirror circuit for detecting the current when the transmission power tube is turned on and converting it into a detection voltage and outputting it to the control circuit.

[0053] The control circuit includes a reference voltage generating circuit 30, a dual comparator circuit 40 and an interval selection circuit 60. The reference voltage generating circuit 30 is provided with M reference voltages of different sizes, and is used to select two of the reference voltages as the first comparison threshold voltage and the second comparison threshold voltage to be output to the dual comparator circuit 40 respectively. The dual comparator circuit 40 inputs the detection voltage, and is used to compare the detection voltage with the first comparison threshold voltage and the second comparison threshold voltage respectively, and output the comparison result to the interval selection circuit 60. The interval selection circuit 60 is provided with M+1 different intervals according to the current detection range when the controllable transmission power tube is turned on, and the thresholds of the M+1 different intervals are The interval selection circuit 60 corresponds to the M reference voltages one by one respectively, and is used to switch the interval according to the comparison result, and output the first control signal and the second control signal to the reference voltage generating circuit 30 and the power transmission circuit 10 respectively, thereby forming a feedback loop. The reference voltage generating circuit 30 is used to reselect the corresponding two reference voltage outputs according to the first control signal, and the power transmission circuit 10 is used to adjust the conduction quantity of the controllable transmission power tube according to the second control signal. The interval selection circuit 60 gradually switches to the optimal interval to which the controllable transmission power tube detection current belongs through the feedback loop, thereby adjusting the controllable transmission power tube to achieve the optimal current mirror ratio.

[0054] See also Figure 4 In this embodiment, the power transmission circuit 10 further includes a first MOS tube MP10, a plurality of switches and M controllable transmission power tubes. The gate of the first MOS tube MP10 is connected to the first voltage, the source thereof is connected to the second voltage, and the drain thereof is connected to the voltage output terminal; the M controllable transmission power tubes are respectively connected in parallel with the first MOS tube MP10, and the gates thereof are respectively connected to the first voltage or the second voltage through the plurality of switches.

[0055] Specifically, in this embodiment, the first MOS tube MP10 and the M controllable transmission power tubes are all PMOS tubes, whose sources are all connected to the second voltage as the power supply voltage, and whose drains are connected to the voltage output terminal. The first voltage is less than the second voltage. Since the gate voltage of the first MOS tube MP10 is always lower than its source voltage, it continues to maintain the on state; the M controllable transmission power tubes respectively switch the input voltage of the gate through the switch control, so as to switch the on or off state of the controllable transmission power tube, specifically: if its gate is connected to the second voltage signal, its gate voltage is lower than the source voltage, at this time, a channel is formed between its source and drain, the PMOS tube is turned on, and the current flows from the source to the drain; if its gate is connected to the first voltage signal, its gate voltage is equal to the source voltage, the channel formed between its source and drain is closed, and the PMOS tube is turned off.

[0056] In this embodiment, the current detection circuit 20 includes a second MOS tube MP2, a clamping circuit and a voltage output circuit. The gate of the second MOS tube MP2 is connected to the first voltage, the source thereof is connected to the second voltage, and the drain thereof is connected to the first input end of the clamping circuit; the second input end of the clamping circuit is connected to the voltage output end of the power transmission circuit 10, and is used to clamp the drain-source voltage of the controllable transmission power tube and the drain-source voltage of the second MOS tube MP2 to equal magnitudes, and output the detection current; the voltage output circuit adopts a voltage-dividing resistor array, and is used to select different voltage output gears according to the second control signal, thereby converting the detection current into the detection voltage output of different magnitudes.

[0057] Specifically, in this embodiment, the second MOS tube MP2 uses the same PMOS tube as the first MOS tube MP10 and the M controllable transmission power tubes to form a current mirror circuit for accurately mirroring the current. Under the same bias conditions, it is possible to accurately replicate the current generated when the controllable transmission power tube is turned on, thereby obtaining the detection current.

[0058] In this embodiment, the ratio of the detection current to the voltage output terminal current of the power transmission circuit 10 is:

[0059]

[0060] in, is the (W / L) size of the second MOS tube, that is, the ratio of the width to the length of the conductive channel, It is the sum of the (W / L) sizes of the first MOS tube and the MOS tube in the on state among the M controllable transmission power tubes.

[0061] Specifically, the clamping circuit of this embodiment includes a clamping amplifier and a third MOS tube MP3, wherein the in-phase input terminal of the clamping amplifier is connected to the drain of the controllable transmission power tube, the inverting input terminal thereof is connected to the drain of the second MOS tube MP2, and the output terminal thereof is connected to the gate of the third MOS tube MP3; the source of the third MOS tube MP3 is connected to the drain of the second MOS tube MP2, and the drain thereof is connected to the voltage output circuit. The clamping amplifier is used to clamp the voltages of the two input terminals to equal magnitudes, so as to ensure that the drain-source voltage VDS voltage of the PMOS tubes MP10 to MP1M in the power transmission circuit 10 and the drain-source voltage VDS voltage of the mirror tube MP2 are equal, thereby ensuring that the magnitude ratio of the current flowing through the two is a fixed set value.

[0062] Specifically, the process of converting the detection current into the detection voltage output in this embodiment includes calibration and voltage division process. The voltage output circuit adopts a calibrable resistor XR1, and the drain of the third MOS tube MP3 is grounded through the calibrable resistor XR1, which is used to calibrate the calibrable resistor XR1 through a register to generate a calibration voltage. The voltage-dividing resistor array is connected in parallel with the calibrable resistor XR1, including M voltage-dividing resistors XR21~XR2M and M control switches. The voltage-dividing resistors XR21~XR2M are connected in series, and the M control switches are respectively connected in parallel with each voltage-dividing resistor XR21~XR2M. When the control switch is in an open state, the voltage-dividing resistor connected in parallel with it is connected for voltage division; if it is closed, the voltage-dividing resistor is in a short-circuit state. The selection of different voltage output gears is achieved by controlling the number of voltage-dividing resistors connected in the voltage-dividing resistor array.

[0063] The calibration voltage is:

[0064] V RES =I SENS *R DET Formula (2)

[0065] Among them, I SENS is the sense current, R DET is the resistance value of the calibrable resistor XR1.

[0066] The ratio of the output detection voltage to the calibration voltage is set to K, then:

[0067] V SENS =V RES *K Formula (3)

[0068] Among them, V SENS The detection voltage is output after calibration and voltage division.

[0069] From equations (2) and (3), we can get:

[0070]

[0071] Among them, I OUT is the voltage output terminal current of the power transmission circuit 10.

[0072] IV conversion ratio factor R f for:

[0073]

[0074] Then from formula (4), we can get:

[0075]

[0076] It can be seen from formula (5) that the deviation of the power tube mirror ratio and the process on the resistance is compensated by the calibrable resistor XR1, and the calibration voltage is divided by the voltage divider resistor array to generate the detection voltage, so that the product of the current mirror ratio and the resistor voltage divider ratio can be kept unchanged in each interval, that is, the parameter K can offset the size ratio of the power tube current mirror, so that the IV conversion ratio factor R f It can be seen that in any mirror image situation, the ratio of the voltage output terminal current of the power transmission circuit 10 and the detection voltage is a fixed value.

[0077] See also Figure 5 Specifically, the reference voltage generating circuit 30 of this embodiment includes a power supply circuit, a voltage transformation circuit, a voltage divider circuit and an output circuit, the power supply module is used to provide a reference voltage, the voltage transformation module is used to convert the reference voltage into a target voltage, the voltage divider module includes M voltage output terminals, which are used to divide the target voltage and output reference voltages of different sizes from its M voltage output terminals to the output circuit respectively, the output circuit is provided with a first voltage output terminal and a second voltage output terminal, and includes 2M control switches, the 2M control switches are connected in parallel in pairs to form a group and are respectively connected in series to the M voltage output terminals, one control switch in each group is connected to the first voltage output terminal, and another control switch in each group is connected to the second voltage output terminal.

[0078] In this embodiment, the comparison logic of the dual comparator circuit 40 is: when the detection voltage is greater than the first comparison threshold voltage or the second comparison threshold voltage, the comparison result is output as 1, and when it is less than the first comparison threshold voltage, the comparison result is output as 0.

[0079] Then the comparison result output by the dual comparator circuit 40 is:

[0080] When the detection voltage is greater than both the first comparison threshold voltage and the second comparison threshold voltage, the comparison result is output as 11.

[0081] When the detection voltage is both smaller than the first comparison threshold voltage and the second comparison threshold voltage, the comparison result is output as 00.

[0082] When the detection voltage is between the first comparison threshold voltage and the second comparison threshold voltage, the comparison result is output as 01.

[0083] Specifically, the dual comparator circuit 40 of this embodiment includes a front comparator U1 and a rear comparator U2, wherein the detection voltage is input to the non-inverting input terminal of the front comparator U1, and the first comparison threshold voltage is input to the inverting input terminal thereof; the detection voltage is input to the non-inverting input terminal of the rear comparator U1, and the second comparison threshold voltage is input to the inverting input terminal thereof. The first comparison threshold voltage is greater than the second comparison threshold voltage, so the comparison result will not be 10.

[0084] See also Figure 6 Specifically, the present embodiment further includes a Debounce circuit 50, the input end of which is connected to the output end of the dual comparator circuit 40, which uses a timer-based Debounce algorithm and is provided with multiple timers to effectively prevent false jitter caused by power supply or other interference. When a signal change is detected, the timer is started; if the signal changes again within the set stable time CK_deb, the timer is reset; only when the timer reaches the set stable time CK_deb can the comparison result of the transmission be confirmed to be stable, thereby ensuring the stability of signal transmission.

[0085] In this embodiment, the interval selection circuit 60 uses an N-bit binary number to represent M+1 different intervals, and the Mth interval is represented by the binary number DRV <n-1>:M=2 N -1.

[0086] If the binary number DRV <n-1>The larger the value, the larger the current detection value corresponding to the interval. The interval switching logic is:

[0087] The condition that the current interval is the optimal interval is: the comparison result is 11, the binary number DRV <n-1>is all 1. Or the comparison result is 00, the binary number DRV <n-1>is all 0. Or the comparison result is 01.

[0088] When the comparison result is 11, the binary number DRV <n-1>When it is not all 1, the binary number DRV <n-1>Add 1 to move up one range.

[0089] When the comparison result is 00, the binary number DRV <n-1>When it is not all 0, the binary number DRV <n-1>Subtract 1, which means moving down one range.

[0090] Specifically, in this embodiment, the interval selection circuit 60 is taken as an example with 8 intervals, at this time M=7, N=3, if the current detection range of the controllable transmission power tube when it is turned on is 0-70mA, then the current switching points are set in increments of 10mA to 10mA, 20mA, 30mA, 40mA, 50mA, 60mA, 70mA, and the corresponding reference voltages are VREF1-VREF7. The 8 intervals are: [0,10mA),

[0091] The binary numbers corresponding to the output of the above intervals are expressed as DRV using three-digit binary numbers. <n-1>=3'b000,DRV <n-1>=3'b001, DRV <n-1>=3'b010, DRV <n-1>=3'b011,DRV <n-1>=3’b100,DRV <n-1>=3'b101, DRV <n-1>=3'b110,DRV <n-1>=3'b111. The first control signals corresponding to the above 8 binary numbers are: VREFO<1:0>={VREF1, VREF1}, VREFO<1:0>={VREF2, VREF1}, VREFO<1:0>={VREF3, VREF2}, VREFO<1:0>={VREF4, VREF3}, VREFO<1:0>={VREF5, VREF4}, VREFO<1:0>={VREF6, VREF5}, VREFO<1:0>={VREF7, VREF7}, VREFO<1:0>={VREF7, VREF7}.

[0092] In this embodiment, a software configuration selection circuit 70 is further included. The software configuration selection circuit 70 is connected to the output end of the interval selection circuit 60 and is used to provide a software configuration value and select an output between the binary number and the software configuration value.

[0093] See also Figure 7 Specifically, in this embodiment, the software configuration circuit generally uses the automatic hardware selection interval, and selects the software configuration value output when performing debugging or a special configuration interval. The software configuration circuit drives the software configuration by inputting the software drive signal SOFTDRVEN, and inputting the software configuration value SOFTDRV <n-1:0>, to retain the flexibility of software configuration.

[0094] In this embodiment, a decoding circuit 80 is also included. The decoding circuit 80 uses thermometer decoding to convert the binary number or software configuration value into a thermometer code as the second control signal output. The thermometer code includes M+1 different values. The larger the value, the more the controllable transmission power tube is turned on and the larger the voltage division ratio of the voltage divider resistor array.

[0095] Specifically, in this embodiment, the interval selection circuit 60 is taken as an example with 8 intervals, and the second control signals corresponding to the above 8 binary numbers are respectively represented by thermometer decoding as: SWEN <m:1>=7'b0000000,CARE <m:1>=7'b0000001,CARE <m:1>=7'b0000011,CARE <m:1>=7'b0000111,CARE <m:1>=7'b0001111,CARE <m:1>=7'b0011111,CARE <m:1>=7'b0111111, CARE <m:1>=7'b1111111.

[0096] Wide range high precision IV conversion method embodiment for real-time monitoring of power transmission

[0097] See also Figure 2 The wide-range high-precision IV conversion method for real-time monitoring of power transmission involved in the embodiment of the present invention is applied to the wide-range high-precision IV conversion circuit for real-time monitoring of power transmission, including:

[0098] S1: The power transmission circuit 10 performs power transmission through the first MOS transistor MP10 and M controllable transmission power transistors, and the reference voltage generation circuit 30 selects two initial reference voltage outputs.

[0099] S2: the current detection circuit 20 detects the conduction current of the first MOS tube MP10 and the controllable transmission power tube and converts it into a detection voltage output; the dual comparison circuit compares the detection voltage with the two reference voltages respectively and outputs the comparison result.

[0100] S3: The interval selection circuit 60 determines whether the current interval is the optimal interval according to the comparison result, and if so, keeps the interval. If not, switches the interval and outputs the first control signal and the second control signal.

[0101] S4: The reference voltage generating circuit 30 reselects the corresponding two reference voltage outputs according to the first control signal, and the power transmission circuit 10 adjusts the conduction number of the controllable transmission power tubes and the voltage dividing ratio of the voltage dividing resistor array according to the second control signal, and returns to execute step S2.

[0102] Specifically, in this embodiment, the interval selection circuit 60 is taken as an example with 8 intervals, at which time M=7, N=3, and if the current detection range of the controllable transmission power tube when it is turned on is 0-70mA, the voltage interval is set in increments of 10mA. The working process of applying the above IV conversion circuit is:

[0103] When power transmission is started, the highest range is selected by default, and DRV <n-1>=3'b111,CARE <m:1>=7'b1111111, the reference voltage generation module outputs VREFO<1:0>={VREF7, VREF7}. If the current of the power transmission is detected to be 15mA, after the first comparison and denounce, DRV <n-1>The value of 1 is reduced to 3'b110, SWEN <m:1>The value of VREFO<1:0> changes to 7'b0111111, and the value of VREFO<1:0> changes to {VREF7, VREF6}. Since the current range corresponding to the interval is (60mA~70mA), it is necessary to go through multiple comparisons and denounces, and the interval continues to be gradually adjusted downward until DRV <n-1>Become 3'b001, SWEN <m:1>It becomes 7'b0000001, VREFO<1:0> becomes {VREF2, VREF1}. At this time, the current range corresponding to the interval is (10mA~20mA), reaching the optimal interval, and is maintained in this interval until the power transmission current changes, and then the above process is repeated.

[0104] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A wide range and high precision IV conversion circuit for real-time monitoring of power transmission, comprising a power transmission circuit, a current detection circuit and a control circuit, wherein the power transmission circuit comprises a plurality of transmission power tubes for power transmission, the current detection circuit and the transmission power tube constitute a current mirror circuit for detecting the current when the transmission power tube is turned on and converting it into a detection voltage and outputting it to the control circuit, characterized in that: The control circuit comprises: A reference voltage generating circuit, a dual comparator circuit and an interval selection circuit, wherein the reference voltage generating circuit is provided with M reference voltages of different sizes, and is used to select two of the reference voltages as a first comparison threshold voltage and a second comparison threshold voltage and output them to the dual comparator circuit respectively, the dual comparator circuit inputs the detection voltage, and is used to compare the detection voltage with the first comparison threshold voltage and the second comparison threshold voltage respectively, and output the comparison result to the interval selection circuit, and the interval selection circuit is provided with M+1 different intervals according to the current detection range when the controllable transmission power tube is turned on, and the thresholds of the M+1 different intervals are respectively the same as the thresholds of the M+1 different intervals. The reference voltages correspond one to one, the interval selection circuit is used to switch the interval according to the comparison result, and output the first control signal and the second control signal to the reference voltage generating circuit and the power transmission circuit respectively to form a feedback loop, the reference voltage generating circuit is used to reselect the corresponding two reference voltage outputs according to the first control signal, the power transmission circuit is used to adjust the conduction quantity of the controllable transmission power tube according to the second control signal, and the interval selection circuit gradually switches to the optimal interval to which the controllable transmission power tube detection current belongs through the feedback loop, thereby adjusting the controllable transmission power tube to achieve the optimal current mirror ratio.

2. The wide range high precision IV conversion circuit for real-time monitoring of power transmission according to claim 1, characterized in that: The power transmission circuit includes a first MOS tube, several switches and M controllable transmission power tubes, the gate of the first MOS tube is connected to the first voltage, the source thereof is connected to the second voltage, and the drain is connected to the voltage output end; the M controllable transmission power tubes are respectively connected in parallel with the first MOS tube, and their gates are respectively connected to the first voltage or the second voltage through several of the switches.

3. The wide range high precision IV conversion circuit for real-time monitoring of power transmission according to claim 2, characterized in that: The current detection circuit includes a second MOS tube, a clamping circuit and a voltage output circuit. The gate of the second MOS tube is connected to the first voltage, the source thereof is connected to the second voltage, and the drain thereof is connected to the first input end of the clamping circuit; the second input end of the clamping circuit is connected to the voltage output end of the power transmission circuit, and is used to clamp the drain-source voltage of the controllable transmission power tube and the drain-source voltage of the second MOS tube to equal magnitudes, and output the detection current; the voltage output circuit adopts a voltage-dividing resistor array, and is used to select different voltage output gears according to the second control signal, thereby converting the detection current into the detection voltage output of different magnitudes.

4. The wide range high precision IV conversion circuit for real-time monitoring of power transmission according to claim 3, characterized in that: The ratio of the detection current to the voltage output terminal current of the power transmission circuit is: in, is the (W / L) size of the second MOS tube, that is, the ratio of the width to the length of the conductive channel, It is the sum of the (W / L) sizes of the first MOS tube and the MOS tube in the on state among the M controllable transmission power tubes.

5. The wide range high precision IV conversion circuit for real-time monitoring of power transmission according to claim 4, characterized in that: The voltage output circuit further includes a calibrable resistor connected to the output end of the clamp circuit, and is used to calibrate the calibrable resistor through a register to ensure that the IV conversion scale factor remains constant; the IV conversion scale factor is: Among them, V SENS is the detection voltage, R DET is the resistance value of the calibrable resistor, and K is: Among them, I SENS is the detection current, V RES is the terminal voltage of the calibrable resistor.

6. A wide range high precision IV conversion circuit for real-time monitoring of power transmission according to any one of claims 1 to 5, characterized in that: The comparison logic of the dual comparator circuit is: when the detection voltage is greater than the first comparison threshold voltage or the second comparison threshold voltage, the comparison result is output as 1, and when it is less than 0, the comparison result is output as 0; Then the comparison result output by the dual comparator circuit is: When the detection voltage is greater than the first comparison threshold voltage and the second comparison threshold voltage, outputting the comparison result as 11; When the detection voltage is both smaller than the first comparison threshold voltage and the second comparison threshold voltage, outputting the comparison result as 00; When the detection voltage is between the first comparison threshold voltage and the second comparison threshold voltage, the comparison result is output as 01.

7. The wide range high precision IV conversion circuit for real-time monitoring of power transmission according to claim 5, characterized in that: The interval selection circuit uses N-bit binary numbers to represent M+1 different intervals, and the Mth interval is represented by the binary number DRV <n-1> ：M＝2 N -1；< / n-1> If the binary number DRV <n-1> The larger the value, the larger the current detection value corresponding to the interval. The interval switching logic is: The condition that the current interval is the optimal interval is: the comparison result is 11, the binary number DRV <n-1>is all 1; or the comparison result is 00, the binary number DRV <n-1> is all 0; or the comparison result is 01; When the comparison result is 11, the binary number DRV <n-1>When it is not all 1, the binary number DRV <n-1> Add 1, that is, increase one interval; When the comparison result is 00, the binary number DRV <n-1>When it is not all 0, the binary number DRV <n-1> Subtract 1, which means moving down one range.

8. The wide range high precision IV conversion circuit for real-time monitoring of power transmission according to claim 1, characterized in that: It also includes a software configuration selection circuit, which is connected to the output end of the interval selection circuit and is used to provide a software configuration value and select an output between the binary number and the software configuration value.

9. The wide range high precision IV conversion circuit for real-time monitoring of power transmission according to claim 8, characterized in that: It also includes a decoding circuit, which uses thermometer decoding to convert the binary number or software configuration value into a thermometer code as the second control signal output, and the thermometer code includes M+1 different values. The larger the value, the more the number of controllable transmission power tubes that are turned on and the larger the voltage division ratio of the voltage divider resistor array.

10. A wide range high precision IV conversion method for real-time monitoring of power transmission, characterized in that, A wide range high precision IV conversion circuit for real-time monitoring of power transmission as claimed in any one of claims 1 to 9, comprising: S1: The power transmission circuit transmits power through the first MOS tube and M controllable transmission power tubes, and the reference voltage generation circuit selects two initial reference voltage outputs; S2: The current detection circuit detects the conduction current of the first MOS tube and the controllable transmission power tube and converts it into a detection voltage output; the dual comparison circuit compares the detection voltage with the two reference voltages respectively and outputs the comparison result; S3: The interval selection circuit determines whether the current interval is the optimal interval according to the comparison result, and if so, maintains the interval; if not, switches the interval and outputs the first control signal and the second control signal; S4: The reference voltage generating circuit reselects the corresponding two reference voltage outputs according to the first control signal, and the power transmission circuit adjusts the conduction number of the controllable transmission power tubes and the voltage dividing ratio of the voltage dividing resistor array according to the second control signal, and returns to execute step S2.

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