Single-power bidirectional current sampling circuit
By designing a single-supply bidirectional current sampling circuit and utilizing a signal pickup modulation module and a voltage regulator to output a reference sampling voltage signal, accurate bidirectional current measurement under single-supply conditions is achieved. This solves the problem of high power consumption in traditional solutions, reduces equipment temperature and power loss, and improves product stability and user experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN ZHIZE TECH CO LTD
- Filing Date
- 2025-05-07
- Publication Date
- 2026-05-22
AI Technical Summary
Traditional single-supply bidirectional current sampling schemes consume a lot of power in high-current applications, leading to increased device temperature, which affects user experience and safety. They are also more complex and costly.
A single-supply bidirectional current sampling circuit is adopted, including a power supply module, a sampling resistor, a signal pickup and modulation module, a voltage regulator, and a sampling module. The reference sampling voltage signal is output through the signal pickup and modulation module and the voltage regulator to achieve accurate bidirectional current measurement, reduce the resistance value of the sampling resistor, and reduce power loss.
It enables accurate bidirectional current measurement under single power supply conditions, reduces power loss of sampling resistor, reduces equipment temperature rise, and improves product stability and user experience.
Smart Images
Figure CN224266874U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sampling circuits, and in particular to a single-power-supply bidirectional current sampling circuit. Background Technology
[0002] With the continuous development of electronic devices, the Type-C connector, with its numerous advantages, has become the standard interface for many smartphones, laptops, and other devices, playing a vital role in data transmission, charging, and especially fast charging, and boasts a vast market prospect. It supports reversible insertion, eliminating the need for users to carefully distinguish between the front and back, making it extremely convenient to use. However, in dual-C male applications, the current direction is not fixed. This presents a challenge for current sampling. Traditional solutions typically employ two sampling resistors to achieve current sampling.
[0003] However, the design with two sampling resistors has significant drawbacks. In high-current applications, increasing the sampling resistors leads to a substantial increase in power consumption, which in turn raises the device temperature. This not only degrades the user experience (e.g., the device's heat affects grip and comfort) but also increases the risk of safety hazards in high-temperature environments, threatening the device's stability and reliability. Another solution is to use dual operational amplifiers to convert the negative signal; however, this increases circuit complexity and cost, hindering product optimization and promotion, and limiting its application scope. Therefore, to address the high power consumption issue of current single-supply bidirectional current sampling, a new technology is needed. Utility Model Content
[0004] The main purpose of this invention is to propose a single-supply bidirectional current sampling circuit, which aims to solve the technical problem of high power consumption in current single-supply bidirectional current sampling circuits.
[0005] To achieve the above objectives, this utility model proposes a single-supply bidirectional current sampling circuit, which includes:
[0006] Power supply module, sampling resistor, signal pickup and modulation module, voltage regulator, sampling module;
[0007] One end of the sampling resistor is connected to the power supply module, the other end of the sampling resistor is connected to the power supply ground, the signal pickup and modulation module is connected in parallel with the sampling resistor, and one end of the voltage regulator is connected to the power supply module;
[0008] The other end of the voltage regulator is connected to the signal pickup and modulation module and the sampling module respectively. The voltage regulator is used to output a reference sampling voltage signal to the signal pickup and modulation module and the sampling module.
[0009] The signal pickup and modulation module is connected to the sampling module, and the signal pickup and modulation module is used to output a reference voltage signal to the sampling module.
[0010] Optionally, in the first implementation, the voltage regulator includes: a regulated input pin, a regulated output pin, a regulated ground pin, a first filter capacitor, and a second filter capacitor. The regulated input pin is connected to the power supply module, the regulated output pin is connected to the signal pickup and modulation module, one end of the first filter capacitor is connected to the regulated input pin, and the other end of the first filter capacitor is connected to the regulated ground pin. One end of the second filter capacitor is connected to the regulated output pin, and the other end of the second filter capacitor is connected to the regulated ground pin.
[0011] Optionally, in the second implementation, the signal pickup and modulation module includes: a pickup ground pin, a first pickup input pin, a second pickup input pin, and a voltage input pin. The voltage input pin is connected to the voltage regulator, the first pickup input pin is connected to one end of the sampling resistor, and the second pickup input pin is connected to the other end of the sampling resistor.
[0012] Alternatively, in the third implementation, the first pickup input pin is grounded, and the second pickup input pin is connected to the power supply ground.
[0013] Optionally, in the fourth implementation, the signal pickup and modulation module further includes a pickup filter capacitor, one end of which is connected to the voltage input pin, and the other end of which is connected to the pickup ground pin.
[0014] Optionally, in the fifth implementation, the sampling module includes an MC9959_QFN20 microcontroller.
[0015] Optionally, in the sixth implementation, the sampling module includes: a sampling filter resistor and a sampling filter capacitor. One end of the sampling filter resistor is connected to the signal pickup and modulation module, and the other end of the sampling filter resistor is connected to one end of the sampling filter capacitor and the MC9959_QFN20 microcontroller.
[0016] Alternatively, in the seventh implementation, the other end of the sampling filter capacitor is grounded.
[0017] Optionally, in the eighth implementation, the signal pickup and modulation module includes an INA199X2 amplifier.
[0018] Optionally, in the ninth implementation, the voltage regulator includes a PJ56L33SQ voltage regulator.
[0019] In this embodiment of the invention, under single-current power supply conditions, by designing the connection relationship between the signal acquisition and modulation module, the voltage regulator, and the sampling module, the signal acquired by the signal acquisition and modulation module from the sampling resistor is filtered, amplified, and transmitted to the sampling module. The voltage regulator then outputs a reference sampling voltage signal, achieving accurate bidirectional current measurement. Simultaneously, the resistance value of the sampling resistor is significantly reduced, lowering the current sampling power loss, reducing measurement insertion loss, lowering product operating temperature, and improving product stability and user experience. This solution enables bidirectional current acquisition using a single sampling resistor, solving the technical problem of high power consumption in current single-supply bidirectional current sampling. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0021] Figure 1 This is the first structural schematic diagram of the single-supply bidirectional current sampling circuit of this utility model;
[0022] Figure 2a This is the first schematic diagram of the second structure of the single-supply bidirectional current sampling circuit of this utility model;
[0023] Figure 2b This is a second schematic diagram of the second structure of the single-supply bidirectional current sampling circuit of this utility model.
[0024] Explanation of icon numbers:
[0025] 101-Power supply module, R5-Sampling resistor, 102-Signal pickup and modulation module, 103-Voltage regulator, 104-Sampling module, C23-First filter capacitor, C24-Second filter capacitor, C5-Pickup filter capacitor, R19-Sampling filter resistor, C26-Sampling filter capacitor.
[0026] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0028] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.
[0029] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, if the word "and / or" appears throughout the text, it means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.
[0030] This invention proposes a single-power-supply bidirectional current sampling circuit.
[0031] In the embodiments of this utility model, such as Figure 1 As shown, Figure 1 This is a first structural schematic diagram of the single-supply bidirectional current sampling circuit of this utility model. The single-supply bidirectional current sampling circuit includes:
[0032] The system includes a power supply module 101, a sampling resistor R5, a signal pickup and modulation module 102, a voltage regulator 103, and a sampling module 104. One end of the sampling resistor R5 is connected to the power supply module 101, and the other end of the sampling resistor R5 is connected to the power ground PGND. The power ground PGND is usually connected to the power ground of the device and may be connected to the power ground of other modules. The purpose is to provide a low-impedance return path for large currents and reduce power loss and heat generation.
[0033] The signal pickup and modulation module 102 is connected in parallel with the sampling resistor R5, and one end of the voltage regulator 103 is connected to the power supply module 101.
[0034] The other end of the voltage regulator 103 is connected to the signal pickup and modulation module 102 and the sampling module 104 respectively. The voltage regulator 103 is used to output a reference sampling voltage signal to the signal pickup and modulation module 102 and the sampling module 104. The reference sampling voltage signal is the signal that actually needs to be sampled. Its voltage value will change with the change of the measured signal, and it can reflect the real-time information of the measured signal.
[0035] The signal pickup and modulation module 102 is connected to the sampling module 104. The signal pickup and modulation module 102 is used to output a reference voltage signal to the sampling module 104. The reference voltage signal is a relatively stable voltage value used as a comparison reference in the sampling process, and is usually provided by a precision voltage source.
[0036] The working principle of this invention is as follows: A reference sampling voltage signal is compared with a reference reference voltage signal to determine the magnitude of the measured signal. In analog-to-digital conversion (A / D conversion), the sampling module 104 compares the reference sampling voltage signal with a series of discrete voltage values generated based on the reference reference voltage signal, thereby determining the magnitude of the reference sampling voltage signal and converting it into a digital quantity. For example, if the reference reference voltage signal is set to 5V, and the reference sampling voltage signal is 2.5V, by comparing it with the 5V reference reference voltage signal, it can be determined that the reference sampling voltage signal is half of the reference reference voltage signal. If the sampling system divides the reference reference voltage signal into 1024 quantization levels, then the quantization value corresponding to this 2.5V reference sampling voltage signal is 512. In this way, the reference reference voltage signal provides a benchmark for the sampling and quantization of the reference sampling voltage signal.
[0037] Please refer to Figure 2a , Figure 2a This is the first schematic diagram of the second structure of the single-supply bidirectional current sampling circuit of this utility model.
[0038] First specific embodiment
[0039] The voltage regulator 103 includes: a voltage input pin VIN, a voltage output pin VOUT, a voltage ground pin GND, a first filter capacitor C23, and a second filter capacitor C24. The voltage input pin VIN is connected to the power supply module 101, and the voltage output pin VOUT is connected to the signal pickup and modulation module 102. One end of the first filter capacitor C23 is connected to the voltage input pin VIN, and the other end of the first filter capacitor C23 is connected to the voltage ground pin GND. One end of the second filter capacitor C24 is connected to the voltage output pin VOUT, and the other end of the second filter capacitor C24 is connected to the voltage ground pin VOUT.
[0040] The signal pickup and modulation module 102 includes: a pickup ground pin GND, a first pickup input pin IN+, a second pickup input pin IN-, and a voltage input pin V+. The voltage input pin V+ is connected to the voltage regulator 103. The first pickup input pin IN+ is connected to one end of the sampling resistor R5, and the second pickup input pin IN- is connected to the other end of the sampling resistor R5. The first pickup input pin IN+ is grounded, and the second pickup input pin IN- is connected to the power ground PGND. The signal pickup and modulation module 102 also includes: a pickup filter capacitor C5. One end of the pickup filter capacitor C5 is connected to the voltage input pin V+, and the other end of the pickup filter capacitor C5 is connected to the pickup ground pin GND.
[0041] Please refer to Figure 2b , Figure 2b This is a second schematic diagram of the second structure of the single-supply bidirectional current sampling circuit of this utility model.
[0042] Second specific embodiment
[0043] The sampling module 104 includes an MC9959_QFN20 microcontroller (MCU). The MC9959_QFN20 is an 8-bit microcontroller (MCU) manufactured by SinoMCU, packaged in a QFN20 package. Its basic parameters are as follows:
[0044] Core: RISC architecture.
[0045] Program memory: 4KB × 16-bit FLASH.
[0046] Data storage: 256 bytes of RAM.
[0047] I / O pins: 18 / 14 / 10 selectable I / O pins.
[0048] Operating voltage: VDD@Fcpu is 1.8V@2M, 2V@4M, 2.4V@8M.
[0049] Package type: QFN20.
[0050] The sampling module 104 includes a sampling filter resistor R19 and a sampling filter capacitor C26. One end of the sampling filter resistor R19 is connected to the signal pickup and modulation module 102, and the other end of the sampling filter resistor R19 is connected to one end of the sampling filter capacitor C26 and the MC9959_QFN20 microcontroller MCU. The other end of the sampling filter capacitor C26 is grounded.
[0051] Working Principle: The power supply module draws power from Vbus, and after step-down, provides a stable DC operating voltage to the signal conditioning and sampling modules. Simultaneously, the voltage regulator generates a stable reference voltage to provide a reference point for the signal pickup and modulation module and the sampling module. The measured current flows through the sampling resistor, generating a weak voltage. This voltage is filtered and proportionally amplified by the signal pickup and conditioning module, which conditions the zero current center value to the reference voltage point. After a low-pass filter removes unwanted signals, the voltage is sent to the AD conversion input port of the sampling module. The internal AD converter samples the input voltage, while another AD converter samples the reference voltage to obtain the reference (zero-point) voltage value. The MC9959_QFN20 microcontroller (MCU) compares the sampled current voltage with the reference voltage to determine the current direction. For example, if the sampled current value is greater than the reference value, the current direction is positive (as defined by the product); otherwise, it is negative. Subtracting the smaller value from the larger value yields the absolute value of the single current. Subsequent filtering algorithms output a stable current value for power calculation, status judgment, and parameter display.
[0052] Furthermore, the signal pickup and modulation module includes an INA199X2 amplifier. The INA199X2 is a model in the INA199 series of current sensing amplifiers manufactured by Texas Instruments (TI), with the following characteristics:
[0053] Wide common-mode range: Allows sensing of voltage drop across shunt resistors at common-mode voltages from -0.3V to 26V, independent of the supply voltage.
[0054] Low offset voltage: The maximum offset voltage is ±150μV, which enables the device to sense current when the maximum voltage drop across the shunt is as low as 10mV (full scale).
[0055] High precision: The maximum gain error of version C is ±1%, and the maximum gain error of versions A and B is ±1.5%; the maximum offset drift is 0.5μV / ℃, and the maximum gain drift is 10ppm / ℃.
[0056] Fixed gain: The fixed gain of INA199X2 is 100V / V.
[0057] Furthermore, the voltage regulator includes a PJ56L33SQ voltage regulator. The PJ56L33SQ is a low dropout linear regulator (LDO) designed and manufactured by PJSEMI, with the following basic parameters:
[0058] Input voltage range: 2V-26V.
[0059] Output voltage: 3.3V, output voltage accuracy: ±2%.
[0060] Output current: The maximum continuous output current is 300mA.
[0061] Package type: SOT-89.
[0062] In this embodiment of the invention, under single-current power supply conditions, by designing the connection relationship between the signal acquisition and modulation module, the voltage regulator, and the sampling module, the signal acquired by the signal acquisition and modulation module from the sampling resistor is filtered, amplified, and transmitted to the sampling module. The voltage regulator then outputs a reference sampling voltage signal, achieving accurate bidirectional current measurement. Simultaneously, the resistance value of the sampling resistor is significantly reduced, lowering the current sampling power loss, reducing measurement insertion loss, lowering product operating temperature, and improving product stability and user experience. This solution enables bidirectional current acquisition using a single sampling resistor, solving the technical problem of high power consumption in current single-supply bidirectional current sampling.
[0063] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. A single-supply bidirectional current sampling circuit, characterized in that, The single-supply bidirectional current sampling circuit includes: Power supply module, sampling resistor, signal pickup and modulation module, voltage regulator, sampling module; One end of the sampling resistor is connected to the power supply module, the other end of the sampling resistor is connected to the power supply ground, the signal pickup and modulation module is connected in parallel with the sampling resistor, and one end of the voltage regulator is connected to the power supply module; The other end of the voltage regulator is connected to the signal pickup and modulation module and the sampling module respectively. The voltage regulator is used to output a reference sampling voltage signal to the signal pickup and modulation module and the sampling module. The signal pickup and modulation module is connected to the sampling module, and the signal pickup and modulation module is used to output a reference voltage signal to the sampling module.
2. The single-supply bidirectional current sampling circuit according to claim 1, characterized in that, The voltage regulator includes: a regulated input pin, a regulated output pin, a regulated ground pin, a first filter capacitor, and a second filter capacitor. The regulated input pin is connected to the power supply module, and the regulated output pin is connected to the signal pickup and modulation module. One end of the first filter capacitor is connected to the regulated input pin, and the other end of the first filter capacitor is connected to the regulated ground pin. One end of the second filter capacitor is connected to the regulated output pin, and the other end of the second filter capacitor is connected to the regulated ground pin.
3. The single-supply bidirectional current sampling circuit according to claim 1, characterized in that, The signal pickup and modulation module includes: a pickup ground pin, a first pickup input pin, a second pickup input pin, and a voltage input pin. The voltage input pin is connected to the voltage regulator. The first pickup input pin is connected to one end of the sampling resistor, and the second pickup input pin is connected to the other end of the sampling resistor.
4. The single-supply bidirectional current sampling circuit according to claim 3, characterized in that, The first pickup input pin is grounded, and the second pickup input pin is connected to the power supply ground.
5. The single-supply bidirectional current sampling circuit according to claim 3, characterized in that, The signal pickup and modulation module further includes a pickup filter capacitor, one end of which is connected to the voltage input pin, and the other end of which is connected to the pickup ground pin.
6. The single-supply bidirectional current sampling circuit according to claim 1, characterized in that, The sampling module includes an MC9959_QFN20 microcontroller.
7. The single-supply bidirectional current sampling circuit according to claim 6, characterized in that, The sampling module includes a sampling filter resistor and a sampling filter capacitor. One end of the sampling filter resistor is connected to the signal pickup and modulation module, and the other end of the sampling filter resistor is connected to one end of the sampling filter capacitor and the MC9959_QFN20 microcontroller.
8. The single-supply bidirectional current sampling circuit according to claim 7, characterized in that, The other end of the sampling filter capacitor is grounded.
9. The single-supply bidirectional current sampling circuit according to claim 1, characterized in that, The signal pickup and modulation module includes an INA199X2 amplifier.
10. The single-supply bidirectional current sampling circuit according to claim 1, characterized in that, The voltage regulator includes: PJ56L33SQ voltage regulator.