Apparatus and method for driving switch

Abstract

An apparatus for driving a switch according to one aspect of the present invention comprises: a main driving unit for driving a switch element; a transition signal generating unit for generating a transition signal indicating a transition of a node voltage in a transition time interval in which a node voltage formed at one node of the switch element transitions when the switch element is switched by the main driving unit; and an auxiliary driving unit enabled by the transition signal to control a driving current for driving the switch element in the transition time interval.

Description

Technology Field

[0001] The present invention relates to an apparatus and method for driving a switch. Background Technology

[0003] FIG. 1 is an example diagram of a driving circuit for a gate driver and peripheral components for driving a switching element such as an FET, and FIG. 2 is a timing diagram showing the operation of the driving circuit of FIG. 1.

[0004] Referring to FIGS. 1 and 2, when the switch element (SW) is turned on, the gate-source junction capacitor (C) of the switch element (SW) is controlled through PWM control of the high-side switch (Q1) and low-side switch (Q2) of the gate driver (GD). gs The charging current for charging the gate-source junction capacitor (C) gs It is supplied via ), and accordingly, the gate-source junction capacitor (C gs ) is charged, and the gate-source voltage (V) of the switch element (SW) GS ) increases (t0~t2). Gate-source voltage (V GS ) is the plateau voltage (V Plateau When it reaches ), the gate-source voltage (V) due to the Miller effect GS ) is the plateau voltage (V Plateau It is maintained constant at ), and the drain-source voltage (V DS ) decreases to the ground voltage level (t2~t3). Subsequently, the gate-drain junction capacitor (C) of the switch element (SW) gd As reverse current flows to the gate driver (GD) through ), the gate-drain junction capacitor (C gd ) is charged, so the gate-source voltage (V GS ) is the supply voltage (V) of the gate driver (GD). CC It reaches ) (t3~t4).

[0005] When the switch element (SW) is turned off, the gate driver (GD) is connected to the gate-source junction capacitor (C gs Discharge current is drawn from ), and accordingly, the gate-source voltage (V GS ) is the plateau voltage (V Plateau It decreases to (t5~t6). Afterwards, the drain-source voltage (V DS ) rises from the ground voltage level (t6~t7), and the gate-drain junction capacitor (C gd As discharge current is drawn from ), the gate-source voltage (V GS ) is the threshold voltage (V th It decreases to below ) (t7~t9).

[0006] When the switch element (SW) operates in the high-frequency region, the drain-source voltage (V) of the switch element (SW) DS The drain-source voltage (V) during the transition interval, that is, the turn-on operation of the switch element (SW). DS The drain-source voltage (V) during the turn-on transition time interval (t2–t3 in FIG. 2) in which ) decreases and the turn-off operation of the switch element (SW) DS Drain-source voltage (V) over time during the turn-off transition time interval (t6–t7 in FIG. 2) in which ) increases DS The rate of change of ) (i.e., dV DS / dt)(drain-source voltage (V) over time DS The slope of ) is related to switching losses and EMI. dV DS As / dt increases, switching losses decrease while EMI increases, and conversely, dV DS As / dt becomes smaller, EMI decreases, while switching losses increase.

[0007] Optimal dV considering these switching losses and EMI trade-offs DS As a method for designing / dt, the gate terminal resistor (R in Fig. 1) on , R off , R g.extA method of adjusting the resistance value of ) may be considered. However, when designing the gate driver (GD), the gate terminal resistor (R) corresponding to the peripheral component located outside the gate driver (GD) on , R off , R g.ext There are practical limitations to designing the resistance value of ). Furthermore, during the switching operation of the switch element (SW), the gate terminal resistance (R) on , R off , R g.ext There is also a lack of circuit means to accurately detect the turn-on transition time interval (t2 to t3 in FIG. 2) and the turn-off transition time interval (t6 to t7 in FIG. 2) corresponding to the timing when the resistance value of ) must be changed.

[0008] The background technology described above is possessed or acquired by the inventor in the process of deriving the content of the disclosure of the present application, and cannot be considered as prior art disclosed to the general public prior to the filing of this application. The problem to be solved

[0010] The present invention was devised to solve the aforementioned problems, and the objective according to one aspect of the present invention is to provide a circuit topology capable of optimizing the trade-off relationship between switching loss and EMI by detecting a turn-on transition time interval during which the drain-source voltage decreases and a turn-off transition time interval during which the drain-source voltage increases when driving a switch element, and by adjusting the slope of the drain-source voltage with respect to time in the detected transition time interval.

[0011] Another objective of the present invention is to provide a circuit topology in which the degree to which the slope of the drain-source voltage, which defines the trade-off relationship between switching loss and EMI, is controlled can be easily changed through a resistive element. means of solving the problem

[0013] An apparatus for driving a switch according to one aspect of the present invention comprises: a main driving unit for driving a switch element; a transition signal generating unit for generating a transition signal indicating a transition of a node voltage in a transition time interval in which a node voltage formed at one node of the switch element transitions when the switch element is switched by the main driving unit; and an auxiliary driving unit enabled by the transition signal to control a driving current for driving the switch element in the transition time interval.

[0014] The present invention is characterized in that, as the driving current is controlled by the auxiliary driving unit, the transition slope of the node voltage in the transition time interval is controlled.

[0015] In the present invention, the transition signal generating unit comprises: a transition sensing voltage generating unit that generates a transition sensing voltage within a predetermined voltage range based on a current formed according to the transition of the node voltage; and a comparison unit that generates the transition signal by comparing the transition sensing voltage generated by the transition sensing voltage generating unit with a predetermined comparison voltage.

[0016] In the present invention, the transition time interval comprises a turn-on transition time interval in which the node voltage decreases according to the turn-on of the switch element, and a turn-off transition time interval in which the node voltage increases according to the turn-off of the switch element, and the comparison unit comprises: a first comparator that generates a first transition signal by comparing a first transition sensing voltage generated by the transition sensing voltage generation unit in the turn-on transition time interval with a predefined first comparison voltage; and a second comparator that generates a second transition signal by comparing a second transition sensing voltage generated by the transition sensing voltage generation unit in the turn-off transition time interval with a predefined second comparison voltage.

[0017] In the present invention, the auxiliary driving unit is characterized by controlling the driving current by supplying a charging current to the junction capacitor of the switch element during the turn-on transition period or drawing a discharge current from the junction capacitor of the switch element during the turn-off transition period.

[0018] In the present invention, the auxiliary driving unit comprises: a first voltage-controlled current source that is enabled by the first transition signal and supplies a charging current to the junction capacitor of the switch element; and a second voltage-controlled current source that is enabled by the second transition signal and draws a discharge current from the junction capacitor of the switch element.

[0019] In the present invention, the auxiliary driving unit further comprises a constant current source; and a resistor element connected to the constant current source; and the first and second voltage control current sources are characterized by having a constant voltage formed as a constant current supplied from the constant current source is applied to the resistor element as an input control voltage.

[0020] In the present invention, the resistance value of the resistor element is characterized by defining the magnitude of the input control voltage of the first and second voltage control current sources, the magnitude of the charging current and the discharging current, and the degree to which the turn-on transition slope and turn-off transition slope of the node voltage are controlled.

[0021] In the present invention, the auxiliary driving unit further comprises a first and second constant current source; and first and second resistor elements connected to the first and second constant current sources, respectively, wherein the first voltage control current source has a constant voltage formed as a constant current supplied from the first constant current source is applied to the first resistor element as an input control voltage, and the second voltage control current source has a constant voltage formed as a constant current supplied from the second constant current source is applied to the second resistor element as an input control voltage.

[0022] In the present invention, the resistance value of the first resistor element defines the degree to which the magnitude of the input control voltage of the first voltage control current source, the magnitude of the charging current, and the turn-on transition slope of the node voltage are controlled, and the resistance value of the second resistor element defines the degree to which the magnitude of the input control voltage of the second voltage control current source, the magnitude of the discharge current, and the turn-off transition slope of the node voltage are controlled.

[0023] In the present invention, when the switch element is turned on by the main driving unit, the first comparator compares the first transition sensing voltage generated by the transition sensing voltage generating unit with the first comparison voltage during the turn-on transition time interval to generate the first transition signal, and the first voltage control current source is enabled by the first transition signal to supply a charging current to the junction capacitor of the switch element, and the turn-on transition slope of the node voltage is adjusted by the charging of the junction capacitor by the charging current.

[0024] In the present invention, when the switch element is turned off by the main driving unit, the second comparator compares the first transition sensing voltage generated by the transition sensing voltage generating unit with the second comparison voltage during the turn-off transition time interval to generate the second transition signal, and the second voltage control current source is enabled by the second transition signal to draw a discharge current from the junction capacitor of the switch element, and the turn-off transition slope of the node voltage is adjusted by the discharge of the junction capacitor by the discharge current.

[0025] In the present invention, the transition slope of the node voltage is characterized by being related to the switching loss and noise generated during the switching operation of the switch element.

[0026] A method for driving a switch according to one aspect of the present invention comprises: a main driving unit driving a switch element; a transition signal generating unit generating a transition signal indicating a transition of a node voltage formed at a node of the switch element during a transition time interval in which the node voltage is transitioned when the switch element is switched by the main driving unit; and an auxiliary driving unit adjusting a driving current for driving the switch element during the transition time interval after being enabled by the transition signal. Effects of the invention

[0028] According to the present invention, a transition signal is generated during a transition time interval in which a voltage (i.e., drain-source voltage) formed at one node (i.e., drain terminal node) of a switch element during a switching operation of the switch element is transitioned, and a driving current for driving the switch element during the transition time interval is controlled through an auxiliary driving unit enabled by the transition signal (i.e., by supplying a charging current to the junction capacitor of the switch element or drawing a discharge current from the junction capacitor), thereby controlling the slope of the drain-source voltage only during the transition time interval in which the slope of the drain-source voltage with respect to time is formed (i.e., the drain-source voltage changes with respect to time), so that the trade-off relationship between the switching loss and EMI of the switch element can be easily optimized, and a circuit topology can be provided in which the degree to which the slope of the drain-source voltage defining the trade-off relationship between the switching loss and EMI is controlled through a resistor element constituting the auxiliary driving unit can be easily changed. Brief explanation of the drawing

[0030] Figure 1 is an example diagram of a driving circuit for a gate driver and peripheral components for driving a switching element such as an FET. Figure 2 is a timing diagram showing the operation of the driving circuit of Figure 1. FIG. 3 is a first circuit diagram for explaining a device for driving a switch according to the present embodiment. Figure 4 is a timing diagram showing the circuit operation of Figure 3. FIG. 5 is a second circuit diagram for explaining a device for driving a switch according to the present embodiment. FIG. 6 is a third circuit diagram for explaining a device for driving a switch according to the present embodiment. FIG. 7 is a fourth circuit diagram for explaining a device for driving a switch according to the present embodiment. FIG. 8 is a flowchart illustrating a method for driving a switch according to the present embodiment. Specific details for implementing the invention

[0031] Hereinafter, an embodiment of an apparatus and method for driving a switch according to the present invention will be described with reference to the attached drawings. In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of explanation. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intention or convention of the user or operator. Therefore, the definitions of these terms should be based on the content throughout this specification.

[0033] FIG. 3 is a first circuit diagram for explaining a device for driving a switch according to the present embodiment, and FIG. 4 is a timing diagram showing the circuit operation of FIG. 3.

[0034] Referring to FIG. 3, the device for driving the switch of the present embodiment (hereinafter, the device) may include a main driving unit (100), a transition signal generating unit (200), and an auxiliary driving unit (300), and the device including each of the above components (100, 200, 300) may operate to drive a switch element (SW). In the present embodiment, the switch element (SW) to be driven may correspond to a semiconductor switch such as a MOSFET (e.g., SiC MOSFET) or an IGBT. As described below, the present embodiment may be configured to detect the voltage transition through a node voltage formed at one node of the switch element (SW). When the switch element (SW) is implemented as a MOSFET, the above node may be a drain terminal node and the node voltage may be a drain-source voltage, and when the switch element (SW) is implemented as an IGBT, the above node may be a collector terminal node and the node voltage may be a collector-emitter voltage. Below, we will explain the case where the switch element (SW) is a MOSFET as an example.

[0035] Each component of this device is described.

[0036] The main driving unit (100) may correspond to a gate driver including a high-side switch and a low-side switch that drives a switch element (SW) as shown in FIG. 1. The main driving unit (100) can drive the switch element (SW) by supplying a charging current to the junction capacitor of the switch element (SW) or drawing a discharge current from the junction capacitor through PWM control by an upper controller (e.g., a processor of the driving IC on which the gate driver is mounted).

[0037] Referring again to FIGS. 1 and 2, the operation of the main driving unit (100) is explained as follows: when the switch element (SW) is turned on, the main driving unit (100) [describes] the gate-source junction capacitor (C) of the switch element (SW). gsThe charging current to charge the gate-source junction capacitor (C) gs It is supplied via ), and accordingly, the gate-source junction capacitor (C gs ) is charged, and the gate-source voltage (V) of the switch element (SW) GS ) increases (t0~t2). Gate-source voltage (V GS ) is the plateau voltage (V Plateau When it reaches ), the gate-source voltage (V) due to the Miller effect GS ) is the plateau voltage (V Plateau It is maintained constant at ), and the drain-source voltage (V DS ) decreases to the ground voltage level (t2~t3). Subsequently, the gate-drain junction capacitor (C) of the switch element (SW) gd As reverse current flows to the main driving unit (100) through the gate-drain junction capacitor (C gd ) is charged, so the gate-source voltage (V GS ) is the supply voltage of the gate driver (V CC It reaches ) (t3~t4).

[0038] When the switch element (SW) is turned off, the main driving unit (100) is a gate-source junction capacitor (C gs Discharge current is drawn from ), and accordingly, the gate-source voltage (V GS ) is the plateau voltage (V Plateau It decreases to (t5~t6). Afterwards, the drain-source voltage (V DS ) rises from the ground voltage level (t6~t7), and the gate-drain junction capacitor (C gd As discharge current is drawn from ), the gate-source voltage (V GS ) is the threshold voltage (V th It decreases to below ) (t7~t9).

[0039] Here, the node voltage formed at one node (i.e., the drain terminal node) of the switch element (SW) (i.e., the drain-source voltage (V) DSThe time interval during which )) transitions is defined as the transition time interval. Referring to FIG. 2, the drain-source voltage (V DS The supply voltage (V) applied to the drain terminal of the switch element (SW) DC The time interval (t2~t3) during which the voltage decreases from )(e.g., external Power Supply Rail voltage) to ground voltage, and the drain-source voltage (V DS ) from the ground voltage, the supply voltage (V DC The time interval (t6~t7) increasing up to ) corresponds to the transition time interval. For a clear distinction of terms, the time interval (t2~t3) is defined as the turn-on transition time interval, and the time interval (t6~t7) is defined as the turn-off transition time interval.

[0040] The transition signal generating unit (200) generates a node voltage (drain-source voltage (V)) during the aforementioned transition time interval when the switching operation of the switch element (SW) by the main driving unit (100) occurs. DS A transition signal representing the transition of )) can be generated. As illustrated in FIG. 3, the transition signal generating unit (200) may include a transition sensing voltage generating unit (210) and a comparison unit (220), and between the drain terminal node of the switch element (SW) and the transition signal generating unit (200), a drain-source voltage (V DS A blocking capacitor (C) for decoupling (i.e., blocking current flow) between the drain terminal node and the transition signal generator (200) during the time interval (t3 to t6) in which ) is maintained constant. BLOCKING ) may be provided.

[0041] The transition sensing voltage generation unit (210) can generate a transition sensing voltage within a predefined voltage range based on the current formed according to the transition of the node voltage. As shown in FIG. 3, the transition sensing voltage generation unit (210) may include a transition sensing circuit (211) and a limiter (212). The transition sensing circuit (211) has a predefined reference voltage (V REF Two resistor elements (R) for distributing ) REF1 , R REF2 It may include ) (two resistive elements (R REF1 , R REF2 The resistance value of ) can be the same), two resistor elements (R REF1 , R REF2 ) connection node (hereinafter, intermediate node (N REF (represented as ) is the aforementioned blocking capacitor (C BLOCKING It can be connected to the drain terminal node of the switch element (SW) through ). The limiter (212) is connected to the voltage formed by the transition sensing circuit (211) (i.e., the intermediate node (N REF Voltage formed in )(V DTDV A transition sensing voltage can be generated by converting ) into a voltage within a predefined voltage range. The predefined voltage range is, for example, a reference voltage (V) above the ground voltage. REF It may correspond to the range below. The transition sensing voltage generated by the transition sensing voltage generating unit (210) may be divided into a first transition sensing voltage corresponding to the turn-on transition time interval and a second transition sensing voltage corresponding to the turn-off transition time interval.

[0042] The comparator (220) can generate a transition signal by comparing the transition sensing voltage generated by the transition sensing voltage generator (210) with a predefined comparison voltage. As shown in FIG. 3, the comparator (220) compares the first transition sensing voltage generated by the transition sensing voltage generator (210) during the turn-on transition time interval with a predefined first comparison voltage (V COMP1 )(e.g.: 0.5V REF A first comparator (221) that generates a first transition signal (ON_DVDT) by comparing it with - 1[V]), and a second transition sensing voltage generated by a transition sensing voltage generator (210) during a turn-off transition time interval, and a predefined second comparison voltage (V COMP2 )(e.g.: 0.5V REF It may include a second comparator (222) that generates a second transition signal (OFF_DVDT) by comparing with + 1[V]). The (+) input terminal of the first comparator (221) is the first comparison voltage (V COMP1 It is connected to ) and the (-) input terminal is connected to the output of the limiter (212). The (-) input terminal of the second comparator (222) is connected to the second comparison voltage (V COMP2 It is connected to ) and the (+) input terminal is connected to the output of the limiter (212).

[0043] In the turn-on transition time interval formed during the turn-on operation of the switch element (SW), the drain-source voltage (V DS ) is the supply voltage (V) applied to the drain terminal of the switch element (SW). DC It decreases from )(e.g., external Power Supply Rail voltage) to ground voltage, and accordingly, the blocking capacitor (C BLOCKING Both ends of ) (i.e., the intermediate node (N REF A voltage difference is formed between the ) and the drain terminal node of the switch element (SW), so that the intermediate node (N REF Current flows from ) to the drain terminal node. Intermediate node (N REF ) voltage (V DTDV) consists of two resistive elements (R REF1 , R REF2 The voltage distributed by ) (i.e., V REF The voltage decreases by an amount corresponding to the current drawn from / 2) to the drain terminal node, and the intermediate node (N REF ) voltage (V DTDV ) is converted into a first transition sensing voltage through a limiter (212). The transition sensing voltage generating unit (210) converts the first transition sensing voltage into a first comparison voltage (V COMP1 It may be pre-designed circuit-wise to have a value lower than ).

[0044] The first transition sensing voltage is input to the first comparator (221), and the first comparison voltage (V) input to the (+) input terminal. COMP1 Since ) is greater than the first transition sensing voltage input to the (-) input terminal, the first comparator (221) generates a high-level first transition signal (ON_DVDT). At the same time, the first transition sensing voltage is input to the second comparator (222), and the first transition sensing voltage input to the (+) input terminal is the second comparison voltage (V) input to the (-) input terminal. COMP2 Since it is smaller than ), the second comparator (222) generates a low-level second transition signal (OFF_DVDT).

[0045] In the turn-off transition time interval formed during the turn-off operation of the switch element (SW), the drain-source voltage (V DS ) is the supply voltage (V) applied from the ground voltage to the drain terminal of the switch element (SW). DC It increases up to ), and accordingly, the blocking capacitor (C BLOCKING Both ends of ) (i.e., the drain terminal node and the intermediate node (N) of the switch element (SW) REF A voltage difference is formed between )) and from the drain terminal node to the intermediate node (N REF Current flows through ). Intermediate node (N REF ) voltage (V DTDV) consists of two resistive elements (R REF1 , R REF2 The voltage distributed by ) (i.e., V REF From / 2) intermediate node (N REF It increases by the voltage component corresponding to the amount of current flowing into ), and the intermediate node (N REF ) voltage (V DTDV ) is converted into a second transition sensing voltage through a limiter (212). The transition sensing voltage generation unit (210) converts the second transition sensing voltage into a second comparison voltage (V COMP2 It may be pre-designed circuit-wise to have a value greater than ).

[0046] The second transition sensing voltage is input to the second comparator (222), and the second transition sensing voltage input to the (+) input terminal is the second comparison voltage (V) input to the (-) input terminal. COMP2 Since it is greater than ), the second comparator (222) generates a high-level second transition signal (OFF_DVDT). At the same time, the second transition sensing voltage is input to the first comparator (221), and the first comparison voltage (V) input to the (+) input terminal is input. COMP1 Since ) is smaller than the second transition sensing voltage input to the (-) input terminal, the first comparator (221) generates a low-level first transition signal (ON_DVDT).

[0047] Next, the auxiliary driving unit (300) is enabled by a transition signal generated by the transition signal generating unit (200) and can adjust the driving current for driving the switch element (SW) during the transition time interval. Here, adjusting the driving current for driving the switch element (SW) means that the charging current (I) to the junction capacitor of the switch element (SW) during the turn-on transition time interval. ON_DVDT ) supplying, or discharge current (I) from the junction capacitor of the switch element (SW) during the turn-off transition period. OFF_DVDTIt means drawing out ). As the driving current of the switch element (SW) is controlled by the auxiliary driving unit (300), the transition slope of the node voltage (i.e., dV) in the transition time interval DS / dt) can be adjusted.

[0048] As illustrated in FIG. 3, the auxiliary driving unit (300) includes an OR gate (ORG) and a constant current source (I SCR ), resistor element (R CNTL It may include a first voltage-controlled current source (310) and a second voltage-controlled current source (320).

[0049] The OR gate (ORG) performs an OR operation on the first and second transition signals (ON_DVDT, OFF_DVDT) output respectively from the first and second comparators (221, 222) of the transition signal generation unit (200). As described above, during the turn-on transition time interval, the first transition signal (ON_DVDT) has a high level value and the second transition signal (OFF_DVDT) has a low level value, and thus a high level signal is output from the OR gate (ORG) during the turn-on transition time interval. During the turn-off transition time interval, the first transition signal (ON_DVDT) has a low level value and the second transition signal (OFF_DVDT) has a high level value, and thus a high level signal is output from the OR gate (ORG) during the turn-off transition time interval. That is, a high-level signal is output from the OR gate (ORG) during the turn-on transition period and the turn-off transition period, and a low-level signal is output during other periods.

[0050] Constant current source (I SCR ) can be configured to be enabled by a signal output from an OR gate (ORG), that is, a constant current source (I SCR ) can be enabled during the turn-on transition time interval and the turn-off transition time interval. The resistive element (R CNTL ) is a constant current source (I SCRIt is connected to a constant current source (I SCR Constant current (I) supplied from ) CNTL ) is a resistive element (R CNTL As it is applied to ), the resistive element (R CNTL ) has a constant voltage (V CNTL ) is formed.

[0051] The first voltage-controlled current source (310) is enabled by the first transition signal (ON_DVDT) and charges the junction capacitor of the switch element (SW) with a charging current (I ON_DVDT ) can be supplied. The first voltage-controlled current source (310) is a constant current source (I SCR Constant current (I) supplied from ) CNTL ) is a resistive element (R CNTL The constant voltage (V) formed as it is applied to ) CNTL It can be configured to have ) as the input control voltage.

[0052] The second voltage-controlled current source (320) is enabled by the second transition signal (OFF_DVDT) and discharges a current (I) from the junction capacitor of the switch element (SW). OFF_DVDT ) can be drawn out. The second voltage-controlled current source (320) is also a constant current source (I SCR Constant current (I) supplied from ) CNTL ) is a resistive element (R CNTL The constant voltage (V) formed as it is applied to ) CNTL It can be configured to have ) as the input control voltage.

[0053] A constant current source (I) during the turn-on transition time interval SCR As ) is enabled, the resistive element (R CNTL Constant voltage (V) on ) CNTL ) is formed, and the first voltage-controlled current source (310) is enabled by the high-level first transition signal (ON_DVDT). The first voltage-controlled current source (310) is a resistor element (R CNTL The constant voltage (V) formed at ) CNTLIt receives ) as the input control voltage, and depending on the input control voltage, the charging current (I ON_DVDT ) is supplied to the junction capacitor of the switch element (SW). Accordingly, during the turn-on transition period, the node voltage (drain-source voltage (V)) of the switch element (SW) DS The transition slope of )) can be adjusted. During the turn-on transition time interval, as the second transition signal (OFF_DVDT) is formed at a low level, the second voltage control current source (320) remains in a disabled state.

[0054] A constant current source (I) during the turn-off transition time interval SCR As ) is enabled, the resistive element (R CNTL Constant voltage (V) on ) CNTL ) is formed, and the second voltage-controlled current source (320) is enabled by the high-level second transition signal (OFF_DVDT). The second voltage-controlled current source (320) is a resistor element (R CNTL The constant voltage (V) formed at ) CNTL It receives ) as an input control voltage, and depending on the input control voltage, discharge current (I) from the junction capacitor of the switch element (SW) OFF_DVDT ) is drawn out. Accordingly, during the turn-off transition period, the node voltage (drain-source voltage (V)) of the switch element (SW) is drawn out. DS The transition slope of )) can be adjusted. During the turn-off transition time interval, as the first transition signal (ON_DVDT) is formed at a low level, the first voltage-controlled current source (310) remains in a disabled state.

[0055] The degree to which the turn-on transition slope and turn-off transition slope of the node voltage of the switch element (SW) are controlled is the charging current (I ON_DVDT ) and discharge current (I OFF_DVDT It varies depending on the magnitude of ), and the charging current (I ON_DVDT ) and discharge current (I OFF_DVDTThe magnitude of ) depends on the magnitude of the input control voltage of the first and second voltage control current sources (310, 320), and the magnitude of the input control voltage of the first and second voltage control current sources (310, 320) is a resistor element (R CNTL Since it depends on the resistance value of ), consequently, the resistive element (R CNTL The resistance value of ) is the magnitude of the input control voltage of the first and second voltage control current sources (310, 320) and the charging current (I ON_DVDT ) and discharge current (I OFF_DVDT Defines the magnitude of ) and the degree to which the turn-on transition slope and turn-off transition slope of the node voltage are controlled. That is, according to the present embodiment, the gate terminal resistance (e.g., R in FIG. 3) G By resolving the problem of practical difficulties in adjusting the resistance value of ), a separately provided resistor element (R CNTL A circuit topology can be provided that allows for easy adjustment of the turn-on transition slope and the turn-off transition slope by adjusting the resistance value of ). In addition, by applying circuit means capable of accurately sensing the timing at which the turn-on transition slope and the turn-off transition slope are formed, an optimal dV considering the trade-off between the switching loss of the switch element (SW) and EMI during the transition time interval is provided DS A circuit topology capable of designing / dt can be provided.

[0056] The circuit operation of the present embodiment is summarized with reference to FIG. 4.

[0057] When the switch element (SW) is turned on, the main driving unit (100) is the gate-source junction capacitor (C) of the switch element (SW). gs The charging current to charge the gate-source junction capacitor (C) gs It is supplied via ), and accordingly, the gate-source junction capacitor (C gs ) is charged, and the gate-source voltage (V) of the switch element (SW) GS) increases (t0~t1). Gate-source voltage (V GS ) is the plateau voltage (V Plateau When it reaches ), the gate-source voltage (V) due to the Miller effect GS ) is the plateau voltage (V Plateau It is maintained constant at ), and the drain-source voltage (V DS ) decreases to the ground voltage level (t1~t2). The time interval t1~t2 of FIG. 4 corresponds to the turn-on transition time interval, and during this turn-on transition time interval, the intermediate node (N) of the transition sensing circuit (211) REF As current flows from ) to the drain terminal node of the switch element (SW), the intermediate node (N REF ) voltage (V DTDV ) decreases. Intermediate node (N REF ) voltage (V DTDV ) is input to the first and second comparators (221, 222) after its magnitude is limited by the limiter (212). A high-level first transition signal (ON_DVDT) is output from the first comparator (221), and a low-level second transition signal (OFF_DVDT) is output from the second comparator (222); accordingly, the first voltage-controlled current source (310) of the auxiliary driver (300) is enabled and the second voltage-controlled current source (320) is disabled. The constant current source (I) is controlled by the high-level signal output from the OR gate (ORG). SCR ) is enabled, and the constant current source (I SCR Constant current (I) supplied from ) CNTL ) is a resistive element (R CNTL The constant voltage (V) formed as it is applied to ) CNTL ) is input to the first voltage control current source (310) as an input control voltage, and the first voltage control current source (310) charges a charging current (I) according to the input control voltage. ON_DVDT ) is supplied to the junction capacitor of the switch element (SW). Accordingly, during the turn-on transition time interval, the drain-source voltage (V) of the switch element (SW) DSThe transition slope of ) can be adjusted.

[0058] When the switch element (SW) is turned off, the main driving unit (100) is a gate-source junction capacitor (C gs Discharge current is drawn from ), and accordingly, the gate-source voltage (V GS ) is the plateau voltage (V Plateau It decreases to (t3~t4). Afterwards, the drain-source voltage (V DS ) rises from the ground voltage level (t4 to t5), and the time interval t4 to t5 in FIG. 4 corresponds to the turn-off transition time interval. During this turn-off transition time interval, from the drain terminal node of the switch element (SW) to the intermediate node (N) of the transition sensing circuit (211) REF As current flows to the intermediate node (N REF ) voltage (V DTDV ) increases. Intermediate node (N REF ) voltage (V DTDV ) is input to the first and second comparators (221, 222) after its magnitude is limited by the limiter (212). A low-level first transition signal (ON_DVDT) is output from the first comparator (221), and a high-level second transition signal (OFF_DVDT) is output from the second comparator (222); accordingly, the first voltage-controlled current source (310) of the auxiliary driver (300) is disabled and the second voltage-controlled current source (320) is enabled. The constant current source (I) is controlled by the high-level signal output from the OR gate (ORG). SCR ) is enabled, and the constant current source (I SCR Constant current (I) supplied from ) CNTL ) is a resistive element (R CNTL The constant voltage (V) formed as it is applied to ) CNTL ) is input to the second voltage control current source (320) as an input control voltage, and the second voltage control current source (320) discharges a current (I) according to the input control voltage. OFF_DVDT) is drawn out to the junction capacitor of the switch element (SW). Accordingly, during the turn-off transition period, the drain-source voltage (V) of the switch element (SW) DS The transition slope of ) can be adjusted.

[0060] In the first embodiment described above, one resistor element (R CNTL A configuration in which the turn-on transition slope and the turn-off transition slope are controlled through ) has been described. That is, according to the first embodiment, the turn-on transition slope and the turn-off transition slope are both controlled by a single resistor element (R CNTL The degree of control is determined by the resistance value of ). However, the optimal dV considering the trade-off between the switching loss of the switch element (SW) and EMI DS The / dt design may need to be performed independently during the turn-on transition time interval and the turn-off transition time interval, and in the second embodiment, the turn-on transition slope and the turn-off transition slope are two resistor elements (R CNTL1 , R CNTL2 It presents a circuit topology that can be independently controlled through ).

[0061] FIG. 5 is a second circuit diagram for explaining a device for driving a switch according to the present embodiment. When referring to FIG. 5, it can be seen that in the second embodiment, only the circuit configuration of the auxiliary driving unit (300) is different from that of the first embodiment.

[0062] As illustrated in FIG. 5, the auxiliary driving unit (300) of the second embodiment comprises first and second constant current sources (I SCR1 , I SCR2 ), first and second resistor elements (R CNTL1, R CNTL2 It may include ), and first and second voltage-controlled current sources (310, 320).

[0063] First constant current source (I SCR1) can be configured to be enabled by a first transition signal (ON_DVDT) output from a first comparator (221), i.e., a first constant current source (I SCR1 ) can be enabled only during the turn-on transition time interval. The first resistor element (R CNTL1 ) is the first constant current source (I SCR1 It is connected to ), and the first constant current source (I SCR1 Constant current (I) supplied from ) CNTL1 ) is the first resistor element (R CNTL1 As applied to ), the first resistor element (R CNTL1 ) has a constant voltage (V CNTL1 ) is formed.

[0064] The first voltage-controlled current source (310) is enabled by the first transition signal (ON_DVDT) and charges the junction capacitor of the switch element (SW) with a charging current (I ON_DVDT ) can be supplied. The first voltage-controlled current source (310) is the first constant current source (I SCR1 Constant current (I) supplied from ) CNTL1 ) is the first resistor element (R CNTL1 The constant voltage (V) formed as it is applied to ) CNTL1 It can be configured to have ) as the input control voltage.

[0065] Second constant current source (I SCR2 ) can be configured to be enabled by a second transition signal (OFF_DVDT) output from a second comparator (222), i.e., a second constant current source (I SCR2 ) can be enabled only during the turn-off transition time interval. The second resistor element (R CNTL2 ) is the second constant current source (I SCR2 It is connected to ), and the second constant current source (I SCR2 Constant current (I) supplied from ) CNTL2 ) is the second resistor element (R CNTL2 As applied to ), the second resistor element (R CNTL2 ) has a constant voltage (V CNTL2 ) is formed.

[0066] The second voltage-controlled current source (320) is enabled by the second transition signal (OFF_DVDT) and discharges a current (I) from the junction capacitor of the switch element (SW). OFF_DVDT ) can be drawn out. The second voltage-controlled current source (320) is the second constant current source (I SCR2 Constant current (I) supplied from ) CNTL2 ) is the second resistor element (R CNTL2 The constant voltage (V) formed as it is applied to ) CNTL2 It can be configured to have ) as the input control voltage.

[0067] During the turn-on transition time interval, the first constant current source (I SCR1 As ) is enabled, the first resistor element (R CNTL1 Constant voltage (V) on ) CNTL1 ) is formed, and the first voltage-controlled current source (310) is enabled by a high-level first transition signal (ON_DVDT). The first voltage-controlled current source (310) is a first resistor element (R CNTL1 The constant voltage (V) formed at ) CNTL1 It receives ) as the input control voltage, and depending on the input control voltage, the charging current (I ON_DVDT ) is supplied to the junction capacitor of the switch element (SW). Accordingly, during the turn-on transition period, the node voltage (drain-source voltage (V)) of the switch element (SW) DS The transition slope of )) can be adjusted. During the turn-on transition time interval, as the second transition signal (OFF_DVDT) is formed at a low level, the second constant current source (I SCR2 ) and the second voltage-controlled current source (320) remain in a disabled state.

[0068] During the turn-off transition time interval, the second constant current source (I SCR2 As ) is enabled, the second resistor element (R CNTL2 Constant voltage (V) on ) CNTL2) is formed, and the second voltage-controlled current source (320) is enabled by the high-level second transition signal (OFF_DVDT). The second voltage-controlled current source (320) is a second resistor element (R CNTL2 The constant voltage (V) formed at ) CNTL2 It receives ) as an input control voltage, and depending on the input control voltage, discharge current (I) from the junction capacitor of the switch element (SW) OFF_DVDT ) is drawn out. Accordingly, during the turn-off transition period, the node voltage (drain-source voltage (V)) of the switch element (SW) is drawn out. DS The transition slope of )) can be adjusted. During the turn-off transition time interval, as the first transition signal (ON_DVDT) is formed at a low level, the first constant current source (I SCR1 ) and the first voltage-controlled current source (310) remain in a disabled state.

[0069] According to the second embodiment of FIG. 5, the first resistor element (R CNTL1 The resistance value of ) is the magnitude of the input control voltage of the first voltage control current source (310) and the charging current (I ON_DVDT Defines the magnitude of ) and the degree to which the turn-on transition slope of the node voltage is controlled. And the second resistor element (R CNTL2 The resistance value of ) is the magnitude of the input control voltage of the second voltage control current source (320) and the discharge current (I OFF_DVDT Defines the magnitude of ) and the degree to which the turn-off transition slope of the node voltage is controlled. That is, the turn-on transition slope and the turn-off transition slope are respectively the first and second resistor elements (R CNTL1 , R CNTL2 It is controlled independently through ).

[0071] FIG. 6 is a third circuit diagram for explaining a device for driving a switch according to the present embodiment, and FIG. 7 is a fourth circuit diagram for explaining a device for driving a switch according to the present embodiment. The embodiment of FIG. 6 is different only in the transition sensing circuit (211) of the transition signal generating unit (200) compared to the first embodiment according to FIG. 3, and the embodiment of FIG. 7 is also different only in the transition sensing circuit (211) of the transition signal generating unit (200) compared to the second embodiment according to FIG. 5.

[0072] According to FIGS. 6 and 7, the transition sensing circuit (211) has one node at a reference voltage (V REF Connected to ) and other nodes (intermediate nodes (N REF )) is a blocking capacitor (C BLOCKING A resistor element (R) connected to the drain terminal node of the switch element (SW) through ) REF It may include ). Compared to the first embodiment according to FIG. 3, the embodiments of FIG. 6 and FIG. 7 include an intermediate node (N REF The voltage level formed in ) is different, and accordingly, the voltage limit value of the limiter (212) and the first comparison voltage (V COMP1 ) and the second comparison voltage (V COMP2 ) may be configured differently from the third embodiment. For example, the voltage limit value of the limiter (212) may be configured to be from 0V to 5V, and the first comparison voltage (V COMP1 ) and the second comparison voltage (V COMP2 ) are each V REF - 1V and V REF It can be configured to +1V. Since the overall circuit operation is the same as the embodiment of FIGS. 3 and FIGS. 5, a detailed description of the operation is omitted.

[0074] FIG. 8 is a flowchart illustrating a method for driving a switch according to the present embodiment. Referring to FIG. 8, the method for driving a switch according to the present embodiment may include a step S100 in which a main driving unit (100) drives a switch element (SW); a step S200 in which a transition signal generating unit (200) generates a transition signal indicating a transition of a node voltage during a transition time interval in which a node voltage formed at one node of the switch element (SW) transitions when the main driving unit (100) performs a switching operation of the switch element (SW); and a step S300 in which an auxiliary driving unit (300) controls a driving current for driving the switch element (SW) during a transition time interval after being enabled by the transition signal. Since the description of each step has been described above, a detailed description of the operation is omitted.

[0076] As used herein, the term “part” may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A part may be a component formed integrally, or a minimum unit of said component or a part thereof that performs one or more functions. For example, according to one embodiment, a part may be implemented in the form of an Application-Specific Integrated Circuit (ASIC). Additionally, the implementation described herein may be implemented, for example, as a method or process, a device, a software program, a data stream, or a signal. Even if discussed only in the context of a single form of implementation (e.g., discussed only as a method), the implementation of the discussed feature may also be implemented in other forms (e.g., a device or a program). A device may be implemented in appropriate hardware, software, and firmware, etc. A method may be implemented in a device such as a processor, which generally refers to a processing device including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. The processor also includes communication devices such as computers, cell phones, portable / personal digital assistants ("PDAs"), and other devices that facilitate the communication of information between end-users.

[0077] Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely illustrative and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the claims below. Explanation of the symbols

[0079] 100: Main drive unit 200: Transition signal generation unit 210: Transition sensing voltage generation unit 211: Transition Sensing Circuit R REF , R REF1 , R REF2 : Resistance element 212: Limiter 220: Comparison section 221: First comparator 222: Second comparator 300: Auxiliary drive unit ORG: OR gate I SCR , I SCR1 , I SRC2 : Constant current source, first constant current source, second constant current source R CNTL , R CNTL1 , R CNTL2 : Resistor element, first resistor element, second resistor element 310: First voltage-controlled current source 320: Second voltage-controlled current source SW: Switch element

Claims

Claim 1 A main driving unit for driving a switch element; a transition signal generating unit for generating a transition signal indicating a transition of a node voltage in a transition time interval during which a node voltage formed at one node of the switch element transitions when the switching operation of the switch element by the main driving unit; and an auxiliary driving unit enabled by the transition signal to control a driving current for driving the switch element in the transition time interval; wherein the transition signal generating unit comprises a transition sensing voltage generating unit for generating a transition sensing voltage within a predefined voltage range based on a current formed according to the transition of the node voltage; An apparatus for driving a switch, comprising: a comparison unit that generates a transition signal by comparing a transition sensing voltage generated by the transition sensing voltage generation unit with a predefined comparison voltage; wherein the transition time interval includes a turn-on transition time interval in which the node voltage decreases according to the turn-on of the switch element, and a turn-off transition time interval in which the node voltage increases according to the turn-off of the switch element; and wherein the comparison unit comprises: a first comparator that generates a first transition signal by comparing a first transition sensing voltage generated by the transition sensing voltage generation unit in the turn-on transition time interval with a predefined first comparison voltage; and a second comparator that generates a second transition signal by comparing a second transition sensing voltage generated by the transition sensing voltage generation unit in the turn-off transition time interval with a predefined second comparison voltage. Claim 2 A device for driving a switch according to claim 1, characterized in that the transition slope of the node voltage in the transition time interval is controlled as the driving current is controlled by the auxiliary driving unit. Claim 3 A device for driving a switch according to claim 1, wherein the auxiliary driving unit controls the driving current by supplying a charging current to the junction capacitor of the switch element during the turn-on transition time interval or drawing a discharge current from the junction capacitor of the switch element during the turn-off transition time interval. Claim 4 A device for driving a switch according to claim 3, wherein the auxiliary driving unit comprises: a first voltage-controlled current source that is enabled by the first transition signal and supplies a charging current to the junction capacitor of the switch element; and a second voltage-controlled current source that is enabled by the second transition signal and draws a discharge current from the junction capacitor of the switch element. Claim 5 A device for driving a switch according to claim 4, wherein the auxiliary driving unit further comprises: a constant current source; and a resistor element connected to the constant current source; and wherein the first and second voltage control current sources have a constant voltage formed as a constant current supplied from the constant current source is applied to the resistor element as an input control voltage. Claim 6 An apparatus for driving a switch according to claim 5, characterized in that the resistance value of the resistor element defines the magnitude of the input control voltage of the first and second voltage control current sources, the magnitude of the charging current and the discharging current, and the degree to which the turn-on transition slope and turn-off transition slope of the node voltage are controlled. Claim 7 An apparatus for driving a switch according to claim 4, wherein the auxiliary driving unit further comprises: a first and a second constant current source; and first and second resistor elements respectively connected to the first and second constant current sources; wherein the first voltage control current source has a constant voltage formed as an input control voltage when a constant current supplied from the first constant current source is applied to the first resistor element, and the second voltage control current source has a constant voltage formed as an input control voltage when a constant current supplied from the second constant current source is applied to the second resistor element. Claim 8 An apparatus for driving a switch according to claim 7, wherein the resistance value of the first resistor element defines the degree to which the magnitude of the input control voltage of the first voltage control current source, the magnitude of the charging current, and the turn-on transition slope of the node voltage are controlled, and the resistance value of the second resistor element defines the degree to which the magnitude of the input control voltage of the second voltage control current source, the magnitude of the discharge current, and the turn-off transition slope of the node voltage are controlled. Claim 9 An apparatus for driving a switch according to claim 4, wherein, when the switch element is turned on by the main driving unit, the first comparator compares the first transition sensing voltage generated by the transition sensing voltage generating unit with the first comparison voltage during the turn-on transition time interval to generate the first transition signal, the first voltage control current source is enabled by the first transition signal to supply a charging current to the junction capacitor of the switch element, and the turn-on transition slope of the node voltage is adjusted by the charging of the junction capacitor by the charging current. Claim 10 An apparatus for driving a switch according to claim 4, wherein, when the switch element is turned off by the main driving unit, the second comparator compares the first transition sensing voltage generated by the transition sensing voltage generating unit with the second comparison voltage during the turn-off transition time interval to generate the second transition signal, the second voltage control current source is enabled by the second transition signal to draw a discharge current from the junction capacitor of the switch element, and the turn-off transition slope of the node voltage is adjusted by the discharge of the junction capacitor by the discharge current. Claim 11 An apparatus for driving a switch, characterized in that, in claim 1, the transition slope of the node voltage is related to the switching loss and noise occurring during the switching operation of the switch element. Claim 12 A main driving unit driving a switch element; a transition signal generating unit generating a transition signal indicating a transition of a node voltage in a transition time interval during which a node voltage formed at one node of the switch element transitions when the switching operation of the switch element by the main driving unit; and an auxiliary driving unit adjusting a driving current for driving the switch element in the transition time interval after being enabled by the transition signal; wherein the transition signal generating unit comprises a transition sensing voltage generating unit that generates a transition sensing voltage within a predefined voltage range based on a current formed according to the transition of the node voltage; A method for driving a switch, comprising: a comparison unit that generates a transition signal by comparing a transition sensing voltage generated by the transition sensing voltage generating unit with a predefined comparison voltage; wherein the transition time interval includes a turn-on transition time interval in which the node voltage decreases according to the turn-on of the switch element, and a turn-off transition time interval in which the node voltage increases according to the turn-off of the switch element; and wherein the comparison unit includes: a first comparator that generates a first transition signal by comparing a first transition sensing voltage generated by the transition sensing voltage generating unit in the turn-on transition time interval with a predefined first comparison voltage; and a second comparator that generates a second transition signal by comparing a second transition sensing voltage generated by the transition sensing voltage generating unit in the turn-off transition time interval with a predefined second comparison voltage. Claim 13 A main driving unit for driving a switch element; a transition signal generating unit for generating a transition signal indicating a transition of a node voltage in a transition time interval in which a node voltage formed at one node of the switch element transitions when the switching operation of the switch element by the main driving unit occurs; An apparatus for driving a switch, comprising: an auxiliary driving unit enabled by the transition signal and controlling a driving current for driving the switch element during the transition time interval; wherein the transition time interval includes a turn-on transition time interval in which the node voltage decreases according to the turn-on of the switch element and a turn-off transition time interval in which the node voltage increases according to the turn-off of the switch element; and wherein the auxiliary driving unit controls the driving current by supplying a charging current to the junction capacitor of the switch element during the turn-on transition time interval and drawing a discharge current from the junction capacitor of the switch element during the turn-off transition time interval. Claim 14 delete

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