A driving circuit and method

Abstract

The present invention discloses a novel driving circuit and method, including resistors R1, R2, R3, capacitor C1, magnetic bead L1, switch tubes Q1, Q2, voltage stabilizing diodes T1, T2 and power switch tube Q3, VIN is a pulse input terminal, and VON is a pulse width output terminal. When VIN inputs a positive pulse drive, the power switch tube Q3 is turned on, and when the positive pulse drive is disconnected, the pulse width is used to maintain the Q3 drive, and when VIN inputs a negative pulse, the switch tube is turned off, and when the negative pulse drive is disconnected, a continuous negative voltage is turned off. The present invention can convert pulse drive into pulse width drive, convert the accuracy of pulse triggering into level triggering, improve control accuracy, and has the ability to quickly open and close.

Description

Technical Field

[0001] The present invention relates to the field of switch tube driving, and in particular to a lithium ion battery online EIS precise measurement system and method. Background Art

[0002] With the continuous development of high power density power supplies, switching tubes, as important control devices for power conversion, account for more than 90% of power failures due to failure of switching tubes, of which direct damage caused by abnormalities in the switching tube drive circuit accounts for more than 30% of the failure rate. A reliable drive circuit is essential for the switching tube to operate in a safe working area.

[0003] In order to solve the problem that the switch tube in a high power density power supply is damaged by the abnormal operation of the driving circuit, which affects the normal operation of the power supply, this patent proposes a new switch tube driving circuit and its design method. Summary of the invention

[0004] The purpose of the present invention is to provide a driving circuit with fast on / off capability, capable of converting pulse drive into pulse width drive, converting the accuracy of pulse triggering into level triggering, and improving control accuracy.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A driving circuit comprises a driving circuit and a pulse circuit, wherein the driving circuit comprises a power switch tube Q3;

[0007] The pulse circuit input is the VIN pulse input terminal, and the output is the VON pulse width output terminal; the pulse circuit includes resistor R1, resistor R2, capacitor C1, switch tube Q1 and its body diode D1, switch tube Q2 and its body diode D2, Zener diode T1, Zener diode T2, one end of resistor R1 is connected to the negative phase end of the pulse input terminal VIN, the other end of R1 is connected to one end of capacitor C1, the other end of C1 is connected to the positive phase end of the pulse input terminal VIN, the source of switch tube Q1 is connected to the positive phase end of the pulse input terminal VIN, the gate is connected to the anode of Zener diode T1, the drain is connected to the cathode of Zener diode T2, and diode D1 is connected in parallel to switch tube Q1. A parasitic diode between the drain and the source, and the anode of D1 is connected to the source of the switch tube Q1, and the cathode of D1 is connected to the drain of the switch tube Q1. The cathode of the voltage-stabilizing diode T1 is connected to the negative phase end of the pulse input end VIN. The source of the switch tube Q2 is connected to the cathode of the voltage-stabilizing diode T1, the drain is connected to the lower end of the resistor R2, and the gate is connected to the anode of the voltage-stabilizing diode T2. The diode D2 is a parasitic diode connected in parallel between the drain and the source of the switch tube Q2, and the anode of D2 is connected to the source of the switch tube Q2, and the cathode of D2 is connected to the drain of the switch tube Q2. The upper end of the resistor R2 is connected to the cathode of T2. The positive end of the VON pulse is connected to the upper end of the resistor R2, and the negative end of the VON pulse is connected to the lower end of the resistor R2.

[0008] Furthermore, the driving circuit includes a resistor R2, a resistor R3, a magnetic bead L1, a power switch tube Q3 and its body diode D3, the upper end of the resistor R2 is connected to one end of the resistor R3, the other end of R3 is connected to one end of the magnetic bead L1, the other end of L1 is connected to the gate of the power switch tube Q3, and the source of the power switch tube Q3 is connected to the lower end of the resistor R2.

[0009] Furthermore, the resistor R3 is the driving resistor of the power switch tube Q3, and its selection range is:

[0010]

[0011] Among them, the value range of the magnetic bead L1 is 10~100nH, and Cgs is the gate-source capacitance of the power switch tube Q3;

[0012] Resistor R2 is the pull-down driving resistor of the power switch tube Q3, and its value range is 10~100kΩ.

[0013] Furthermore, the selection range of capacitor C1 is:

[0014]

[0015] Where W is the energy of single pulse drive, U is the drive voltage, and Ciss is the input capacitance of the power switch tube Q3.

[0016] Furthermore, the selection range of resistor R1 is:

[0017]

[0018] in is the single pulse driving time, It is the positive pulse width time.

[0019] Furthermore, the switch tubes Q1 and Q2 are both NMOS tubes, and the regulated voltages of the zener diodes T1 and T2 are lower than the input drive voltage VIN.

[0020] Furthermore, the selection of Zener diodes T1 and T2 is:

[0021]

[0022] Among them, VT is the stabilization voltage of the voltage regulator diode T1 or T2, VQ is the driving voltage of the switch tube Q1 or Q2, and U is the input driving voltage value of VIN.

[0023] A driving method for the above driving circuit, when VIN inputs a positive pulse driving, the positive pulse charges the capacitor C1 through the resistor R1, the body diode D1 of the switch tube Q1 is positively turned on, the switch tube Q1 is turned off, the voltage stabilizing diode T2 is reversely turned on for voltage stabilization, the switch tube Q2 is positively turned on, and the VIN input voltage is applied to both ends of the resistor R2 for positive voltage driving;

[0024] When VIN becomes a negative pulse, the negative pulse reverse charges the capacitor C1 through the resistor R1, and the Zener diode T1 withstands the negative voltage and conducts reversely to stabilize the voltage. The switch tube Q1 is turned on by the positive voltage, and the cathode of the Zener diode T2 is connected to the negative end of the input voltage VIN and withstands the reverse negative voltage. It cannot reach the reverse breakdown voltage and is turned off. At the same time, the driving voltage of the switch tube Q2 disappears, Q2 is turned off, and the body diode D2 of Q2 withstands the forward voltage and is turned on. The resistor R2 is connected in parallel with the input voltage VIN, and the negative pulse is applied to the power switch tube Q3 to turn off the switch tube.

[0025] Furthermore, when the VIN positive pulse drive is disconnected, the switch tube Q1 continues to remain off, the body diode D1 continues to be turned on, the forward voltage on the capacitor C1 continues to be applied to the voltage zener diode T2 through D1, the gate of the switch tube Q2 is still subjected to the positive voltage and turned on, the capacitor C1 is discharged through D1, R2, Q2, and R1, the resistors R1 and R2 are connected in series to divide the voltage across the capacitor C1, and when the voltage across the resistor R2 is higher than the driving voltage of the power switch tube Q3, Q3 is kept turned on, achieving the effect of pulse width driving, and realizing the conversion from pulse driving to pulse width driving;

[0026] When the negative pulse drive of VIN is disconnected, the negative voltage on capacitor C1 continues to be applied to the Zener diode T1 through resistor R1, T1 continues to withstand reverse breakdown voltage stabilization, the gate of switch tube Q1 still withstands positive voltage and is turned on, Zener diode T2 and switch tube Q2 are still in the off state, Q2 body diode D2 is still turned on, capacitor C1 is discharged through R1, D2, R2, and Q1, resistors R1 and R2 are connected in series to divide the voltage across capacitor C1, and the negative voltage across resistor R2 is applied to the power switch tube Q3, achieving continuous negative pressure and shutdown.

[0027] The advantages of the present invention are:

[0028] By adjusting the pulse width, the working state of the load device can be controlled very accurately. The duty cycle can be adjusted dynamically to make the system control more flexible and respond quickly to external changes to meet different application requirements.

[0029] The circuit is relatively simple, easy to design and implement, which helps to reduce system cost and energy loss, especially in applications where output power needs to be adjusted frequently.

[0030] The drive circuit is in a fully on or fully off state most of the time, which reduces power loss and improves overall efficiency;

[0031] In summary, the present invention can drive a driving circuit that can both drive pulse control and adjust the duty cycle of pulse width control. The circuit structure of the present invention is simple, the reliability is high, and it has the accuracy of pulse control and the duty cycle adjustment function of pulse width control, and has broad prospects for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The driving circuit of embodiment 1 of the present invention;

[0033] Figure 2 This is a working principle diagram of the positive pulse drive of Example 2 of the present invention;

[0034] Figure 3 This is a working principle diagram of the positive pulse disappearance of Example 2 of the present invention;

[0035] Figure 4 This is a working state diagram of negative pulse shutdown of embodiment 2 of the present invention;

[0036] Figure 5 This is a working principle diagram of Example 2 of the present invention after the negative pulse disappears. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0038] Example 1

[0039] A driving circuit, please refer to Figure 1 , including a driving circuit and a pulse circuit. The driving circuit includes a resistor R2, a resistor R3, a magnetic bead L1, a power switch tube Q3 and its body diode D3. The upper end of the resistor R2 is connected to one end of the resistor R3, the other end of R3 is connected to one end of the magnetic bead L1, the other end of L1 is connected to the gate of the power switch tube Q3, and the source of the power switch tube Q3 is connected to the lower end of the resistor R2.

[0040] The pulse circuit includes a resistor R1, a resistor R2, a capacitor C1, a switch tube Q1 and its body diode D1, a switch tube Q2 and its body diode D2, a Zener diode T1, and a Zener diode T2. One end of the resistor R1 is connected to the negative phase end of the pulse input terminal VIN, the other end of R1 is connected to one end of the capacitor C1, the other end of C1 is connected to the positive phase end of the pulse input terminal VIN, the source of the switch tube Q1 is connected to the positive phase end of the pulse input terminal VIN, the gate is connected to the anode of the Zener diode T1, the drain is connected to the cathode of the Zener diode T2, and the diode D1 is a parasitic diode connected in parallel between the drain and source of the switch tube Q1. The anode of D1 is connected to the source of the switching tube Q1, the cathode of D1 is connected to the drain of the switching tube Q1, the cathode of the voltage-stabilizing diode T1 is connected to the negative phase end of the pulse input end VIN, the source of the switching tube Q2 is connected to the cathode of the voltage-stabilizing diode T1, the drain is connected to the lower end of the resistor R2, and the gate is connected to the anode of the voltage-stabilizing diode T2. The diode D2 is a parasitic diode connected in parallel between the drain and source of the switching tube Q2, and the anode of D2 is connected to the source of the switching tube Q2, the cathode of D2 is connected to the drain of the switching tube Q2, the upper end of the resistor R2 is connected to the cathode of T2, the positive end of the VON pulse is connected to the upper end of the resistor R2, and the negative end of the VON pulse is connected to the lower end of the resistor R2.

[0041] Resistor R3 is the driving resistor of power switch tube Q3, and its selection range is:

[0042]

[0043] Among them, the value range of the magnetic bead L1 is 10~100nH, and Cgs is the gate-source capacitance of the power switch tube Q3;

[0044] Resistor R2 is the pull-down driving resistor of the power switch tube Q3, and its value range is 10~100kΩ.

[0045] The selection range of capacitor C1 is:

[0046]

[0047] Where W is the energy of single pulse drive, U is the drive voltage, and Ciss is the input capacitance of the power switch tube Q3.

[0048] The selection range of resistor R1 is:

[0049]

[0050] in is the single pulse driving time, It is the positive pulse width time.

[0051] Furthermore, the switch tubes Q1 and Q2 are both NMOS tubes, and the regulated voltages of the zener diodes T1 and T2 are lower than the input drive voltage VIN.

[0052] Furthermore, the selection of Zener diodes T1 and T2 is:

[0053]

[0054] Among them, VT is the stabilizing voltage of the Zener diode T1 or T2, VQ is the driving voltage of the switch tube Q1 or Q2, and U is the input driving voltage value of VIN.

[0055] Example 2

[0056] A driving method of the above driving circuit, when VIN inputs a positive pulse driving, the working principle is as follows Figure 2 As shown, the positive pulse charges the capacitor C1 through the resistor R1, and at the same time, the body diode D1 of the switch tube Q1 is turned on by the positive voltage, and Q1 itself is in the off state. The cathode of the voltage regulator diode T2 is the positive level of VIN, and the voltage regulator diode T2 is reversed and stabilized. The gate input voltage of the switch tube Q2 is VIN-VD2 (VD2 is the voltage regulator voltage of the voltage regulator diode T2). The switch tube Q2 is turned on due to the positive voltage, so the voltage at the lower end of the resistor R2 is the same as the negative end of the VIN input, and the upper end of the resistor R2 is the same as the positive end of the VIN input (ignoring the voltage drop of the Q1 body diode D1). At this time, the VIN input voltage is applied to both ends of the resistor R2, and the driving voltage drives the power switch tube Q3 with a positive voltage through the driving resistor R1 and the magnetic bead L1, and the switch tube is turned on.

[0057] When the VIN positive pulse driver is disconnected, the working principle is as follows Figure 3 As shown, the switch tube Q1 continues to remain off, the body diode D1 continues to be turned on, the forward voltage on the capacitor C1 continues to be applied to the voltage-stabilizing diode T2 through D1, and the gate of the switch tube Q2 is still subjected to positive voltage and turned on. This process is that the capacitor C1 is discharged through D1, R2, Q2, and R1. Ignoring the conduction voltage of D1 and Q2, the resistor R1 and the resistor R2 are connected in series to divide the voltage across the capacitor C1. During the VIN input pulse disconnection process, as long as the voltage across the resistor R2 is higher than the driving voltage of the power switch tube Q3, Q3 can be kept turned on, achieving the effect of pulse width drive, and realizing the conversion from pulse drive to pulse width drive.

[0058] When VIN becomes a negative pulse, the working principle is as follows Figure 4As shown, the negative pulse reversely charges the capacitor C1 through the resistor R1, and the voltage of the capacitor C1 becomes positive at the bottom and negative at the top. At the same time, the Zener diode T1 is subjected to negative voltage and reverse conducts to stabilize the voltage. The gate voltage of the switch tube Q1 is VIN-VD1 (VD1 is the stabilizing voltage of the Zener diode T1). The switch tube Q1 is turned on due to the positive voltage. At this time, the cathode of the Zener diode T2 is connected to the negative end of the input voltage VIN. The Zener diode T2 is subjected to reverse negative voltage and cannot reach the reverse breakdown voltage and is turned off. At the same time, the driving voltage of the switch tube Q2 disappears, causing Q2 to be in the off state, and the Q2 body diode is turned on due to the forward voltage. In this process, the resistor R2 is connected in parallel with the input voltage VIN, and the negative pulse is applied to the power switch tube Q3 through the resistor R3 and the magnetic bead L1 to turn off the switch tube.

[0059] When the VIN negative pulse driver is disconnected, the working state is as follows Figure 5 As shown, the negative voltage on capacitor C1 continues to be applied to Zener diode T1 through resistor R1, T1 continues to withstand reverse breakdown voltage stabilization, and the gate of switch tube Q1 still withstands positive voltage and conducts. Zener diode T2 and switch tube Q2 are still in the off state, and Q2 body diode D2 is still turned on. This process is that capacitor C1 is discharged through R1, D2, R2, and Q1, ignoring the conduction voltage drop of the Zener diode tube and the switch tube Q1. At this time, the process is that resistors R1 and R2 are connected in series to divide the voltage across capacitor C1, and the negative voltage across resistor R2 is applied to the power switch tube through resistor R3 and magnetic bead L1, achieving continuous negative pressure and shutting down.

[0060] The switch tubes Q1 and Q2 described in this embodiment are selected as NMOS switch tubes to improve the turn-on and turn-off speeds of the driving circuit.

[0061] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A driving circuit, comprising a driving circuit, wherein the driving circuit comprises a power switch tube Q3, characterized in that: It also includes a pulse circuit, a resistor R2, a resistor R3, a magnetic bead L1, a power switch tube Q3 and its body diode D3; The pulse circuit input is the VIN pulse input terminal, and the output is the VON pulse width output terminal; The pulse circuit includes a resistor R1, a resistor R2, a capacitor C1, a switch tube Q1 and its body diode D1, a switch tube Q2 and its body diode D2, a Zener diode T1, and a Zener diode T2. One end of the resistor R1 is connected to the negative phase end of the pulse input terminal VIN, the other end of R1 is connected to one end of the capacitor C1, the other end of C1 is connected to the positive phase end of the pulse input terminal VIN, the source of the switch tube Q1 is connected to the positive phase end of the pulse input terminal VIN, the gate is connected to the anode of the Zener diode T1, the drain is connected to the cathode of the Zener diode T2, and the diode D1 is a parasitic diode connected in parallel between the drain and source of the switch tube Q1. The anode of D1 is connected to the source of the switch tube Q1, the cathode of D1 is connected to the drain of the switch tube Q1, the cathode of the voltage-stabilizing diode T1 is connected to the negative phase end of the pulse input end VIN, the source of the switch tube Q2 is connected to the cathode of the voltage-stabilizing diode T1, the drain is connected to the lower end of the resistor R2, the gate is connected to the anode of the voltage-stabilizing diode T2, the diode D2 is a parasitic diode connected in parallel between the drain and source of the switch tube Q2, and the anode of D2 is connected to the source of the switch tube Q2, the cathode of D2 is connected to the drain of the switch tube Q2, the upper end of the resistor R2 is connected to the cathode of T2, the positive end of the VON pulse is connected to the upper end of the resistor R2, and the negative end of the VON pulse is connected to the lower end of the resistor R2; The upper end of the resistor R2 is connected to one end of the resistor R3, the other end of R3 is connected to one end of the magnetic bead L1, the other end of L1 is connected to the gate of the power switch tube Q3, and the source of the power switch tube Q3 is connected to the lower end of the resistor R2.

2. The driving circuit according to claim 1, characterized in that: The resistor R3 is the driving resistor of the power switch tube Q3, and its selection range is: Among them, the value range of the magnetic bead L1 is 10~100nH, and Cgs is the gate-source capacitance of the power switch tube Q3; The resistor R2 is a pull-down driving resistor of the power switch tube Q3, and its value range is 10-100 kΩ.

3. The driving circuit according to claim 1, characterized in that: The selection range of capacitor C1 is: Where W is the energy of a single pulse drive, U is the input drive voltage value of VIN, and Ciss is the input capacitance of the power switch tube Q3.

4. The driving circuit according to claim 1, characterized in that: The selection range of the resistor R1 is: in is the single pulse driving time, It is the positive pulse width time.

5. The driving circuit according to claim 1, characterized in that: The switch tubes Q1 and Q2 are both NMOS tubes, and the regulated voltage of the zener diodes T1 and T2 is lower than the input drive voltage VIN.

6. The driving circuit according to claim 5, characterized in that: The selection of the voltage zener diodes T1 and T2 is: Among them, VT is the stabilizing voltage of the Zener diode T1 or T2, VQ is the driving voltage of the switch tube Q1 or Q2, and U is the input driving voltage value of VIN.

7. A driving method based on the driving circuit according to any one of claims 1 to 6, characterized in that: When VIN inputs a positive pulse drive, the positive pulse charges the capacitor C1 through the resistor R1, the body diode D1 of the switch tube Q1 is turned on by the positive voltage, the switch tube Q1 is turned off, the voltage regulator diode T2 is reversed and stabilized, the switch tube Q2 is turned on by the positive voltage, and the VIN input voltage is applied to both ends of the resistor R2 for positive voltage driving; When VIN becomes a negative pulse, the negative pulse reverse charges the capacitor C1 through the resistor R1, and the Zener diode T1 withstands the negative voltage and conducts reversely to stabilize the voltage. The switch tube Q1 is turned on by the positive voltage, and the cathode of the Zener diode T2 is connected to the negative end of the input voltage VIN and withstands the reverse negative voltage. It cannot reach the reverse breakdown voltage and is turned off. At the same time, the driving voltage of the switch tube Q2 disappears, Q2 is turned off, and the body diode D2 of Q2 withstands the forward voltage and is turned on. The resistor R2 is connected in parallel with the input voltage VIN, and the negative pulse is applied to the power switch tube Q3 to turn off the switch tube.

8. The driving method of the driving circuit according to claim 7, characterized in that: When the VIN positive pulse drive is disconnected, the switch tube Q1 continues to remain off, the body diode D1 continues to be turned on, the forward voltage on the capacitor C1 continues to be applied to the voltage-stabilizing diode T2 through D1, the gate of the switch tube Q2 is still subjected to positive voltage and turned on, the capacitor C1 is discharged through D1, R2, Q2, and R1, and the resistors R1 and R2 are connected in series to divide the voltage across the capacitor C1. When the voltage across the resistor R2 is higher than the driving voltage of the power switch tube Q3, Q3 is kept turned on, achieving the effect of pulse width drive, and realizing the conversion from pulse drive to pulse width drive; When the negative pulse drive of VIN is disconnected, the negative voltage on capacitor C1 continues to be applied to the Zener diode T1 through resistor R1, T1 continues to withstand reverse breakdown voltage stabilization, the gate of switch tube Q1 still withstands positive voltage and is turned on, Zener diode T2 and switch tube Q2 are still in the off state, Q2 body diode D2 is still turned on, capacitor C1 is discharged through R1, D2, R2, and Q1, resistors R1 and R2 are connected in series to divide the voltage across capacitor C1, and the negative voltage across resistor R2 is applied to the power switch tube Q3, achieving continuous negative pressure and shutdown.

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