Low-delay large-current solid-state relay with state feedback

Abstract

The utility model relates to a power supply field especially relates to a low delay large current solid state relay with state feedback, including the primary side of coupling inductance is connected with non optical coupling PWM controller, external input voltage respectively, digital isolator receives the drive input signal from external controller and sends state output signal to external controller, one end of the secondary side of coupling inductance is connected with internal ground terminal and the anode of schottky diode, the cathode of schottky diode is as the output end of isolated power supply and is connected with one end of the secondary side of coupling inductance and internal ground terminal through a capacitor, the first output end of digital isolator is connected with the input end of driver, the second input end is connected with one end of load resistance, the anode of signal diode, the other end of load resistance is connected with internal low voltage power supply, the cathode of signal diode is connected with internal ground terminal, the utility model uses the digital isolator of capacitor isolation type, can realize low transmission delay, and according to the application requirement configuration grid resistance.

Description

Technical Field

[0001] This utility model relates to the field of power supply, and in particular to a low-delay, high-current solid-state relay with status feedback. Background Technology

[0002] Traditional solid-state relays are mainly divided into two types: magnetically isolated and optically isolated. Optically isolated solid-state relays usually have a large on-state voltage drop, low current, and low efficiency, while magnetically isolated solid-state relays usually have a large delay and large size.

[0003] In certain specific fields, magnetically isolated and optically isolated solid-state relays cannot achieve high current, low delay, and small size in order to achieve low latency, high current, and miniaturization. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model proposes a low-delay, high-current solid-state relay with status feedback. The solid-state relay includes an isolated power supply, a digital isolator, a voltage regulator module, a driver, and a signal diode. The isolated power supply includes a non-optically coupled PWM controller, a coupling inductor, and a Schottky diode. The external input voltage and external ground are connected to the isolated power supply and the digital isolator, respectively. The primary winding of the coupling inductor is connected to both the non-optically coupled PWM controller and the external input voltage. The digital isolator receives the drive input signal from the external controller at its first input terminal and sends the status output signal to the external controller at its second output terminal. The controller has one end of the secondary side of the coupling inductor connected to the internal ground and the anode of the Schottky diode. The cathode of the Schottky diode, as the output of the isolated power supply, is connected to one end of the secondary side of the coupling inductor and the internal ground through a capacitor. The first output of the digital isolator is connected to the input of the driver, the second input is connected to one end of the load resistor and the anode of the signal diode, the other end of the load resistor is connected to the internal low-voltage power supply, the cathode of the signal diode is connected to the internal ground, the positive and negative outputs of the driver are each connected to a gate resistor, and the other ends of the two gate resistors are connected to the gate of a MOSFET.

[0005] Compared with the prior art, the present invention has the following beneficial effects:

[0006] 1. This utility model uses a capacitor-isolated digital isolator, which can achieve low transmission delay;

[0007] 2. This utility model can be configured with two gates according to application requirements, and the conduction speed can be adjusted by configuring two gate resistors;

[0008] 3. This utility model integrates an optocoupler-free PWM controller, which can realize a miniaturized, highly integrated isolated power supply. It also integrates a low-resistance MOSFET, which can achieve high current. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a low-delay, high-current solid-state relay with status feedback according to the present invention.

[0010] Figure 2 This is a schematic diagram of the test waveforms of the driver section of this utility model under high-speed applications;

[0011] Figure 3 This is a schematic diagram of the waveform for monitoring the turn-on signal and switch status under high-speed applications according to this utility model;

[0012] Figure 4 This is a schematic diagram of the test waveforms of the driver section of this utility model under low-speed application, where Figure (a) shows the input and output waveforms when turned on and Figure (b) shows the input and output waveforms when turned off.

[0013] Figure 5 This is a schematic diagram of the turn-on signal and switch status monitoring waveforms of this utility model under low-speed application, wherein Figure (a) shows the waveforms of the input signal and status monitoring signal when the switch is turned on, and Figure (b) shows the waveforms of the input signal and status monitoring signal when the switch is turned off.

[0014] Among them, 1. Solid-state relay; 11. Isolated power supply; 12. Digital isolator; 13. Voltage regulator module; 14. Driver; V IN External input voltage; GND, external ground terminal; Drive_IN, drive input signal; STATE_OUT, status output signal; T1, coupling inductor; D1, Schottky diode; D2, signal diode; C1, first capacitor; C2, second capacitor; C3, third capacitor; Q1, MOSFET; R pull-up Load resistance; R L Load resistor; ISO_5V, internal low-voltage power supply; ISO_12, internal high-voltage power supply; ISO_GND, internal ground terminal; R ON First gate resistor; R off Second gate resistor; V LOAD Load voltage; IN, driver input terminal; POUT, driver positive output terminal; NOUT, driver negative output terminal; INA, digital isolator first input terminal; INB, digital isolator second input terminal; OUTA, digital isolator first output terminal; OUTB, digital isolator first output terminal. Detailed Implementation

[0015] 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.

[0016] This invention proposes a low-delay, high-current solid-state relay with status feedback. The solid-state relay includes an isolated power supply, a digital isolator, a voltage regulator module, a driver, and a signal diode. The isolated power supply includes a non-optically coupled PWM controller, a coupling inductor, and a Schottky diode. An external input voltage and an external ground terminal are connected to the isolated power supply and the digital isolator, respectively. The primary side of the coupling inductor is connected to both the non-optically coupled PWM controller and the external input voltage. The digital isolator receives a drive input signal from an external controller at its first input terminal and sends a status output signal to the external controller at its second output terminal. One end of the secondary side of the coupling inductor is connected to an internal ground terminal and the anode of the Schottky diode. The cathode of the Schottky diode serves as the output terminal of the isolated power supply and is connected to one end of the secondary side of the coupling inductor and the internal ground terminal via a capacitor. The first output terminal of the digital isolator is connected to the input terminal of the driver, and the second input terminal is connected to one end of a load resistor and the anode of the signal diode. The other end of the load resistor is connected to an internal low-voltage power supply, and the cathode of the signal diode is connected to an internal ground terminal. The positive and negative output terminals of the driver are each connected to a gate resistor, and the other ends of the two gate resistors are connected to the gate of a MOSFET.

[0017] This embodiment provides, as follows: Figure 1 In one specific implementation shown, a linear regulator is selected to implement the function of the voltage regulation module. The solid-state relay 1 specifically includes the following parts:

[0018] The isolation power supply 11 is used to convert the primary-side voltage into a secondary-side isolation voltage output. In this embodiment, an optocouplerless flyback topology is adopted. The isolation power supply includes an optocouplerless PWM controller, a coupling inductor T1, and a Schottky diode D1. The two ends of the primary side of the coupling inductor are respectively connected to the external voltage V. IN The non-optically coupled PWM controller uses a coupling inductor secondary side connected to the anode of a Schottky diode. The cathode of the Schottky diode serves as the output terminal of the isolated power supply, which outputs the internal high-voltage power supply ISO_12V. This port is also connected to one end of the second capacitor C2. The other end of the first capacitor is connected to the internal ground terminal ISO_GND and the other end of the coupling inductor secondary side. In addition, a first capacitor is connected between the isolated power supply and the external voltage. The other end of the first capacitor is connected to the external ground terminal. This capacitor acts as a high-frequency filter capacitor, filtering out high-frequency noise in the power supply, reducing power supply ripple, and providing a stable power supply for the chip.

[0019] Digital isolator 12 is used to transmit the primary-side drive signal and the secondary-side status signal. In this embodiment, it is transmitted via an external voltage V. IN The internal low-voltage power supply ISO_5V powers the device. The external controller's drive input signal Drive_IN serves as the input to the first input terminal INA of the digital isolator. The first output terminal OUTA of the digital isolator is connected to the driver input terminal IN. The digital isolator is also connected to both an external ground terminal and an internal ground terminal. The second input terminal INB of the digital isolator is connected to the load resistor R. pull-up One end of the signal diode D2 is connected to the anode, and the load resistor R is connected to the load resistor R. pull-up The other end is connected to the internal low-voltage power supply; the cathode of the signal diode is connected to the internal ground terminal and one end of the MOSFET Q1. For example, in this embodiment, an N-type MOSFET is selected, and the cathode of the signal diode is connected to the internal ground terminal and the drain of the N-type MOSFET. In this embodiment, when the MOSFET is turned on, the signal diode pulls the anode low and clamps it to 0.7V. When the MOSFET is turned off, the anode is pulled up to +5V. The switch status signal can be transmitted back through the digital isolator.

[0020] In this embodiment, isolation between the control side and the functional side is achieved using isolated power supplies and digital isolators;

[0021] The voltage regulator module 13 is used to step down the internal high-voltage power supply output by the isolation power supply to the internal low-voltage power supply, and use the internal high-voltage power supply and the internal low-voltage power supply to power other internal modules. Specifically, in this embodiment, a linear voltage regulator is selected. The internal high-voltage power supply output by the isolation power supply is used as the input of the linear voltage regulator. The linear voltage regulator outputs the internal low-voltage power supply. A third capacitor C3 is provided between the output terminal of the linear voltage regulator and its ground terminal. The ground terminal of the linear voltage regulator is connected to the internal ground terminal.

[0022] Driver 14 has its input terminal IN connected to the first input terminal INA of the digital isolator. The driver's ground terminal is connected to the internal ground terminal. An internal high-voltage power supply powers the driver. The driver's positive output terminal POUT is connected to the first gate resistor R. ON Connect the driver's negative output terminal NOUT to the second gate resistor R. off Connection, first gate resistor R ON Second gate resistor R off The other end is connected together and then connected to the gate of the MOSFET;

[0023] In one embodiment of this invention, an N-type MOSFET is selected, with its source connected to the load voltage V. LOAD connect.

[0024] As an optional implementation, the optocouplerless PWM controller in this embodiment is generally selected from LT8301, LT8302, SW8301EO, or similar controllers. The inductance of the coupling inductor T1 is usually 5uH~50uH, and the output voltage is configured to be 12V.

[0025] As an optional implementation, the digital isolator in this embodiment is generally a bidirectional dual-channel digital isolator, which is a capacitor-isolated digital isolator, and is generally selected from similar digital isolators such as ISO7321 and SW7321EO.

[0026] The voltage regulator module of this utility model is implemented using a linear regulator, a Zener diode, or a reference source. As an optional implementation, a low-power linear regulator is selected, such as LM117, ADP7142, SW7142, or a similar linear regulator. As an optional implementation, a 3.3V~5V Zener diode can be used to replace the linear regulator.

[0027] In practical applications of this invention, the turn-on and turn-off times can be adjusted by changing the resistance values ​​of the two gate resistors connected to the driver. For example, in high-speed applications, the resistance values ​​of the two gate resistors can be set within the range of 2Ω to 10Ω. Figure 2 In standard acquisition mode, the sampling rate is set to 2.50 GSa / s, the high voltages of the two channels are 2.00V and 5.00V respectively, the rise time delay of the two channels is 58.4ns, and the fall time delay is 54.0ns; the waveforms of the turn-on signal and switch status monitoring are as follows: Figure 3 As shown, the frequencies of the two channels are approximately the same; in low-speed applications, the resistance values ​​of the two gate resistors are set within the range of 1kΩ to 100kΩ, as follows. Figure 4 The test waveforms obtained from the driver section show that the turn-on delay is approximately 648µs and the turn-off delay is approximately 92µs. The turn-on signal and switch status monitoring waveforms are as follows: Figure 5 As shown.

[0028] As an optional implementation, the MOSFET can be selected according to the application requirements. Generally, MOSFETs such as SC100N100AEE can be selected, with an on-resistance as low as 3.5mΩ, a maximum drain-source voltage of 100V, and support for steady-state load current of 10A and above, and pulse load current of 100A.

[0029] The above-described embodiments further illustrate the purpose, technical solution, and advantages of this utility model. It should be understood that the above-described embodiments are merely preferred embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made to this utility model within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A low-delay, high-current solid-state relay with status feedback, comprising an isolated power supply, a digital isolator, a voltage regulator module, a driver, and a signal diode, wherein the isolated power supply includes an optocouplerless PWM controller, a coupling inductor, and a Schottky diode, characterized in that, The external input voltage and external ground are connected to the isolation power supply and the digital isolator, respectively. The primary side of the coupled inductor is connected to the optocouplerless PWM controller and the external input voltage, respectively. The first input terminal of the digital isolator receives the drive input signal from the external controller, and the second output terminal sends the status output signal to the external controller. One end of the secondary side of the coupled inductor is connected to the internal ground terminal and the anode of the Schottky diode. The cathode of the Schottky diode serves as the output terminal of the isolation power supply and is connected to one end of the secondary side of the coupled inductor and the internal ground terminal through a capacitor. The first output terminal of the digital isolator is connected to the input terminal of the driver, and the second input terminal is connected to one end of the load resistor and the anode of the signal diode. The other end of the load resistor is connected to the internal low-voltage power supply, and the cathode of the signal diode is connected to the internal ground terminal. The positive and negative output terminals of the driver are each connected to a gate resistor, and the other ends of the two gate resistors are connected to the gate of a MOSFET.

2. The low-delay, high-current solid-state relay with status feedback according to claim 1, characterized in that, The voltage regulator module is used to step down the internal high-voltage power output from the isolated power supply to the internal low-voltage power supply, and then use the internal high-voltage power supply and the internal low-voltage power supply to power other internal modules.

3. A low-delay, high-current solid-state relay with state feedback according to claim 1 or 2, characterized in that, The voltage regulator module is implemented using a linear regulator, Zener diode, or reference source.

4. A low-delay, high-current solid-state relay with state feedback according to claim 3, characterized in that, Choose a low-power linear regulator such as LM117, ADP7142 or SW7142, or a 3.3V~5V Zener diode.

5. A low-delay, high-current solid-state relay with state feedback according to claim 1 or 2, characterized in that, The internal low-voltage power supply is 5V DC, and the internal high-voltage power supply is 12V DC.

6. A low-delay, high-current solid-state relay with state feedback according to claim 1, characterized in that, The on / off time is adjusted by regulating the resistance values ​​of the two gate resistors connected to the driver.

7. A low-delay, high-current solid-state relay with status feedback according to claim 1 or 6, characterized in that, The resistance of the two gate resistors is 2Ω~10Ω.

8. A low-delay, high-current solid-state relay with state feedback according to claim 1 or 6, characterized in that, The resistance of the two gate resistors is 1kΩ~100kΩ.

9. A low-delay, high-current solid-state relay with state feedback according to claim 1, characterized in that, When the MOSFET is turned on, the signal diode pulls the anode low and clamps it to 0.7V. When the MOSFET is turned off, it pulls the anode up to the potential of the internal low-voltage power supply.

Images