JPS63274364A - Power converter - Google Patents

Abstract

PURPOSE:To improve general-purpose properties and extendability of an apparatus by making a power IC have an external output function and by driving another semiconductor device. CONSTITUTION:A control circuit 2 for a monolithic integrated circuit apparatus 1 supplies a driving signal I3 to a semiconductor switching means 3 such as MOS transistor connected with a first terminal 4 connectable with a power supply 8 and a second terminal 5 connectable with a load 10 in response to a control signal 7 inputted from the outside. Further, the control circuit 2 is composed of a logical circuit 2-1 outputting a signal to the next stage in response to the control signal 7 inputted from the outside, a first driving circuit 2-2 outputting said driving signal I3 by the signal 7, and a second driving circuit 2-3 outputting a second current I2. Thus, an output current can be increased by the parallel arrangement of a power converter including a power IC and another semiconductor device resulting in a large current capacity.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to power conversion devices, and in particular to high voltage integrated circuit devices (hereinafter referred to as power This invention relates to improving the versatility and expandability of power conversion devices including ICs.

[Prior Art] In recent years, there has been a significant demand for monolithic integrated circuits for drive circuits for motors and solenoids, power supplies, etc., and for these applications, high voltage (100 V or more) and large current (LA or more) power semiconductor devices are required. A compatible drive function for transistor-transistor logic (TTL) is required. What meets these demands is a power IC in which a control circuit and the above-mentioned power semiconductor element are formed on a single semiconductor substrate. The advantages of using power ICs are:
High-density integration reduces size and weight, lowers costs, and improves ease of use and reliability thanks to control circuits with built-in protection functions. However, since the functions are different for each of the above-mentioned applications, it is necessary to manufacture a wide variety of products in small quantities, and currently, due to the problem of temperature rise, there is a limit to the current capacity of power semiconductor elements that can be integrated with control circuits. There is also a drawback. At present, it is difficult to generalize power ICs, and the only option is to design them for each application. Regarding the increase in current capacity, for example, 5 Nikkei Electronics 1987, 1
As described in pages 139 to 154 of the May 26th issue, there are methods for reducing the on-resistance and suppressing temperature rise of field effect transistors (MO8F, 11:T) used as power semiconductor devices, and Layouts and the like are being considered to reduce thermal interference in control circuits. However, these countermeasures are largely dependent on future device development.

[Problem that the invention seeks to solve]

The above conventional technology does not take into consideration the versatility and expandability of a power conversion device including a power IC. The cost was high due to the variety of manufacturing. In addition, as a countermeasure against temperature rise, it is necessary to keep the power semiconductor element and the control circuit sufficiently apart, and the power I
There was also the problem that the C chip size increased.

An object of the present invention is to provide a power converter including a power IC that can be applied to loads with different current capacities and has excellent versatility and expandability.

The above purpose is to provide a power IC with a multi-output function, to drive other semiconductor devices, and to create a power conversion device that can handle various loads when used in combination with the semiconductor device. This can be achieved by configuring.

[Effect]

According to the present invention, the power IC in the power conversion device has a power semiconductor element as a switch means in the output stage as before, and turns on and off the switch means by a drive signal supplied from the control circuit to output current to the load. It also has a function of outputting the second current when the switch means is on. This second current has a smaller current capacity than the output current to the load, but since the timing of generation and termination can be controlled by the control circuit, it can be used as a drive signal for other semiconductor devices. For example, it is possible to connect a power IC and the other semiconductor device in parallel to increase the capacity of the current supplied to the load, and also to use the second current as a drive circuit for another semiconductor device. Versatility as a power conversion device including

Expandability can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, 1 is a monolithic integrated circuit device, preferably integrated on a single semiconductor substrate.

The control circuit 2 responds to a control signal 7 input from the outside,
A drive signal I8 is supplied to the switching means 3 connected to a first terminal 4 connectable to a TlZ source 8 and to a second terminal 5 connectable to a load 1o. bipolar transistor, MO
A semiconductor switch means 3 such as an S transistor receives a drive signal 1.
3 is supplied, it is in the on state, and when not supplied, it is in the off state. A current 11 is a current supplied to the load 10 when the switch means 3 is in an on state, and a voltage V□ indicates a voltage across the switch means 3 with the terminal S as a reference potential. The third terminal 6 outputs the second electrical current 2, which is a feature of the present invention, to the outside.

The voltage V2 represents the voltage at the third terminal 6 with the terminal 5 as a potential reference. Note that the electric current 2 is a current that can flow from the terminal 6 toward the terminal 5 due to the voltage v2. The integrated circuit with the above configuration has a power supply of 8. and a load 10, forming a closed circuit.

Next, the operation of this embodiment will be explained with reference to FIG. The figure shows the above-mentioned drive signal Ia p fIt flow I I I
Z.

and a time chart of voltage V t V z.

First, at time tx=tz and during the period from t3 to 1+.

A drive signal 8 is supplied from the control circuit 2 to the switch means 3, the switch means 3 is turned on, and a current It flows from the terminals 4 to 5. During this period, the control circuit 2 outputs the second current I2 from the terminal 6, which is a feature of the present invention.

This relationship is the voltage Vl with respect to the current II and Iz.

To explain in terms of VZ, during the period 1=0 to t1 in which the drive (= sign Is is not applied), the switch means 3 is in the OFF state,
Power supply voltage Vo applied from the outside is blocked between terminals 4 and 5. If this state is set as the high level of the voltage (1), one voltage (2) is at a low level with a near zero since the current Iz is not output.

Next, when a drive signal is applied and the switch means 3 is turned on, (1) is reduced to the on-voltage vo11 of the power semiconductor element constituting the switch means 3.

This state corresponds to a low level of vl. At this time, a potential difference sufficient to cause current to flow through the electric current generator 2 is generated at v2, and the voltage is at a high level.

As shown in FIG. 2, currents 1 and I2 and voltages v1 and v2 are each substantially synchronized.

However, in the high level state, vl is equal to the power supply voltage vO.
Compared to this, the value of VZ is small, and even in a high level state, it is comparable to the signal voltage inside the control circuit. The current I2 that can be flowed by applying the voltage v2 described above is a signal level current, and is smaller than the allowable value of the current 11 that the switch means 3 can flow.

A feature of this embodiment is that the current Iz and voltage v2 having the above properties are output.

In FIG. 1, the generation of the second electric current 2 is a function of the control circuit 2, but this embodiment can be realized with the configuration shown in FIG. 3. That is, in FIG. 3, the control circuit 2 includes a logic circuit 2-1 which outputs a signal to the next stage in response to a control signal 7 inputted from the outside, and a logic circuit 2-1 which outputs a signal to the next stage in response to a control signal 7 inputted from the outside, and a logic circuit 2-1 which outputs a drive signal circuit 8 to the switch means 3 in response to the signal. 1 drive circuit 2-2, and a second drive circuit 2-3 which outputs a second current I2 based on the above signal. Here, in order to obtain the characteristics shown in FIG. 2 described above, it is necessary to operate the first drive circuit 2-2 and the second drive circuit 2-3 synchronously. Furthermore, the third
In the embodiment shown in the figure, the switch means 3 of FIG.
It is composed of bipolar transistors. Also, in the same figure,
9 represents a power supply for the control circuit. Here, the configuration of a closed circuit connected by the power source 8 (positive electrode), the load 10, and the integrated circuit device 1 shown in the figure is called a low-side switch.

In contrast, the order of connections is the power supply (positive pole).

When used as an integrated circuit device or as a load, it is called a high-side switch, and is mainly used for automobile lamps, solenoids, etc. In the example of the low side switch in Figure 3,
The current I2 flows between the terminal 6 and the lower terminal 4. of the potentials across the switch means. flowing between

The present invention can be applied not only to low-side switches but also to high-side switches.

Next, as another embodiment for obtaining the characteristics shown in FIG. 2, a configuration as shown in FIG. 4 may be used. In the figure, a MOSFET 3 that can be driven by a voltage signal is used as the switch means.

In the embodiment shown in FIG. 3, the drive signal and the second current for the switch means are generated by the first and second drive circuits inside the control circuit. Although not shown, the logic circuit shown in FIG. 3 and the first drive circuit described above are present, but there is no second drive circuit. That is,
The voltage signal applied from the control circuit to MO5FIl'T 3 is branched, and then a second current is generated via amplification means 11 and output from terminal 6. In addition, switch means 12-1 and 12-2 are connected in the middle, which are turned on and off by the control circuit, and these are connected at the time of generation and termination of the voltage signal applied to MO5F[ET 3, and the output from terminal 6. Second to do
This is to separately control the point at which the generation of current ends. However, when both switch means are on, the drive signal and the second current are synchronized.

The amplifying means 11 is used when the capacity of the second current is insufficient just by branching the voltage signal, or for the purpose of avoiding interference from the outside, and is constituted by a buffer.

Detection means 13 detects at least one of the temperature near the switch means 3 or the current flowing through the switch means, and provides a detection signal to the control circuit 2.

Here, if either the temperature or the current exceeds a predetermined value, the control circuit 2 turns off the switch means 12-2, and as a result, the MOSFET 3 is also turned off, and the current supplied to the load is cut off. Ru. However, the first drive circuit (not shown) inside the control circuit 2 continues to output the voltage signal, and continues to output the second current.

Incidentally, when supplying current to the load again, the switch means 12-2 may be turned on.

In this way, the drive signal generator δ and the second current generator 2.

Basically, they are synchronized, but by providing switch means 12-1 and 12-2, it becomes possible to control the above-mentioned I8 and I2 separately.

Next, an embodiment will be described in which a power conversion device including an integrated circuit according to the present invention is used to drive another semiconductor device, and the device and the power conversion device are used together to improve versatility and expandability. .

First, FIG. 5 shows an example in which another semiconductor element is directly driven using a power conversion device having a configuration similar to that of FIG. 4 described above. In the figure, MO3FIETs 3-1 to 3-6 are connected to a three-phase inverter configuration.

In this way, if there are multiple switch means,
The same number of second terminals 6-1 to 6-6 as the switch means are provided, and a second current is output from each terminal. Here, in the MOSFET of each phase, the upper side (3-1,
3-3, 3-5) and the lower side (3-2, 3-4, 3-6) is in the on state, the potential used as a reference for the second current differs. Furthermore, the value of the potential used as the reference is different for each phase. Therefore, the level shifter 14 provides a difference in reference potential to the voltage drive signal and the second current for each MO5FET.

The semiconductor elements (in this embodiment, MOSFETs 15-1 to 15-6) driven by the aforementioned second current also have a three-phase inverter configuration. The elements are M present at corresponding positions in the integrated circuit 1 with respect to phase and upper or lower side.
These MOSs can be operated in parallel with OSFETs.
A second current obtained by branching the FET drive signal is supplied.

Note that the MOSFETs 15-1 to 15-6 may be monolithic integrated circuit devices integrated within a single semiconductor substrate, or may be formed on separate semiconductor substrates. .

A05FET 15-1~ driven by second current
15-6 are MO8FIETs inside the integrated circuit 1, respectively.
3-1 to 3-6 have a larger current capacity than those of 3-1 to 3-6.

Although this embodiment is directed to a three-phase load, the operation will be explained for the case where a current of U flows as an example, and the explanation of the remaining phases will be omitted.

First, the control circuit 2 consists of the upper MOSFET 3-1 of the U group.
A drive signal for turning on MOSFET 3-4 in the lower stage of V group is output. Here, the drive signal for the U phase is changed by the level shifter 14 so that the potential reference is equal to the voltage of the power supply 18.

Each of the above driving signals is transmitted to the amplifying means 11-1 and 11.
-4 to form a second current through terminals 6-3, and 6-4;
-4 and MOSFETs 15-1 and 15
-4 to turn it on. During this time, assuming that there is no delay between the drive signal and the second current, the four MOSFETs can operate in parallel.

As mentioned above, MOSFETs 15-1 and 15-4 have a larger current capacity than MOSFETs 3-1 and 3-4, and are driven by a signal via an amplification means, so MOSFETs 15-1 and 15-4 are
The output current 4 flowing through the FETs 15-1 and 15-4 is larger than the output current Il flowing through the MOSFETs 3-1 and 3-4, and the control circuit 2 continues to share the responsibility of the output currents 1 and 4, so that both is supplied to the load 10.

Next, the capacity of load 10 changes, and the above ■□ becomes MOSFE.
When the current capacity of T3-1 and T3-4 is exceeded, the switching means 12-2 and 12-2 are activated by a signal from the control circuit 2.
2-7 is in the off state, turning off the above element. At this time, if the current flow 4 flowing through the MOSFETs 15-1 and 15-4 does not exceed the current capacity of the element, the switch means 1
2-1 and 12-8 remain on, but if the capacity is exceeded, a signal from the control circuit is received to turn them off.

In the embodiment shown in FIG. 5, the second current is connected to M
Supplied to the gate of OSFET, integrated circuit 1 and the above MOS
We attempted to increase the current supplied to the load by parallelizing FETs.

Similarly, as shown in the embodiment of FIG. 6, integrated circuits having the same configuration may be connected in parallel to increase the output current. That is, in FIG. 6, the second current (2) output from the terminal 6-1 of one integrated circuit 1-1 is input to the control circuit device 2-2 of the other integrated circuit 1-2, and -2
may be operated in synchronization with the electrician 2. As a result, the switch means in each device has 95FE.
73-1 and 3-2 operate in parallel and can supply a current twice the sum of the output currents of each device to the load.

In the embodiments shown in FIGS. 5 and 6, the integrated circuit 1 and other semiconductor devices are parallelized so that the switching means 3 composed of MOSFETs included inside the integrated circuit and the same number of MOSFETs included in the other semiconductor devices are arranged in parallel. The corresponding positions of both MO3FETs were operated in parallel. However, the number of both MO3FETs does not necessarily have to be the same.

As described above, the integrated circuit 1 has the feature that it functions as a switch that supplies the current generator 1 to the load, and also functions as a drive circuit by outputting the second current Iz to another semiconductor device. Here, if we consider the case where the above-mentioned Il is sufficiently smaller than the current I4 supplied to the load from another semiconductor device, it can be considered that the integrated circuit 1 substantially works only as a driving circuit.

Therefore, FIG. 7 shows an embodiment in which the integrated circuit 1 is used as a base drive circuit of the power transistor 15. In the figure, a terminal 4 of an integrated circuit 1 is connected to the positive electrode of a power source 8, a terminal 5 is connected to a base electrode of a power transistor, and a MOSFET 3, which is a switching means, controls the base current of the transistor.

Here, a Zener diode 16 is connected between the terminal 6 and the terminal 5 in the direction shown. In this Zener diode, the reverse voltage v2, which is constant due to the Zener characteristic, is M
It is assumed that the voltage is larger than the threshold value of the OSFET and smaller than the drive/signal voltage Vg when the MOSFET is turned on, with the terminal 5 as the reference potential. Also, power transistor and power supply 8
Between the negative electrode of the load 1o and the overcurrent detection means 1
3 is provided. In this embodiment, when operating within the range of current capacity allowed by the power transistor 15,
The switch means 12-2 is turned on and the switch means 12-1 is turned off. The control circuit 2 applies a drive signal voltage V to the gate electrode of the MOSFET 3 to turn on the element.

Flow current X1. In this way, the transistor 15 supplied with the base current 11 turns on, and supplies the current source 4 to the load 10.

The above-described operation continues as long as the current I4 is not an overcurrent. However, for some reason, an overcurrent exceeding the allowable current capacity of the transistor or load occurs, and the detection means 1
When a detection signal is output from the control circuit 2 to the control circuit 2, the switch means 12-1 receives the signal from the control circuit 2 and turns on.

As a result, the gate voltage of MOSFET 3 is clamped to the constant voltage v2 of the Zener diode, the base voltage It decreases, and at the same time the current I4 supplied to the load also decreases. Thereafter, when the cause of the overcurrent is eliminated, the switch means 12-1 is turned off again, and the current In is increased to the normal level.

As described above, the present embodiment is characterized in that the second terminal 6 is connected to a Zener diode and is used for the purpose of clamping the drive signal voltage to the MOSFET 3.

〔Effect of the invention〕

According to the present invention, it is possible to increase the output current by paralleling a power conversion device including a power IC with another semiconductor device having a large current capacity, and also when the power IC is used as a drive circuit for another semiconductor device. .

By using the power IC in combination with other devices, it is possible to improve the versatility and expandability that conventional power ICs do not have, such as being able to provide a clamp when an overcurrent occurs.

[Brief explanation of the drawing]

FIG. 1 is a functional configuration diagram of the power conversion device of the present invention, FIG. 2 is an explanatory diagram of the operation of FIG. 1, FIG. 3 is a block diagram when the second current is formed inside the control circuit, and FIG. The figure is a block diagram when the drive signal is branched to form the second current.
The figure shows a block diagram when operating in parallel with other semiconductor devices, Figure 6 is a block diagram when operating integrated circuits in parallel, and Figure 7 shows an integrated circuit equipped with a clamping function when an overcurrent occurs. FIG. 3 is a block diagram when used as a drive circuit. 1...Multi-output monolithic integrated circuit device, 2...
control circuit, 3... switch means and semiconductor element (MO
SFET, etc.), 4...first terminal, 5...second terminal, 6...third terminal, 7...
・Control signal, 8...Power supply, 9...Power supply for control circuit,
DESCRIPTION OF SYMBOLS 10... Load, 11... Amplifying means, 12... Switching means, 13... Detecting means, 14... Level shifter, 15... Other semiconductor devices, 16... Zener diode.

Claims (1)

[Claims] 1. The device has first and second terminals, is connected to the first and second terminals, is turned on or off in response to a drive signal, and carries a first current. a monolithic integrated circuit comprising: at least one switch means for controlling; and a control circuit for providing the drive signal to the switch means in response to an externally input control signal; connected to the first terminal of the integrated circuit; A power converter device in which a power source connected to the switch means and a load connected to the second terminal are connected in series to form a closed circuit, wherein a third terminal is provided in the monolithic integrated circuit, and a third terminal of the switch means is connected to the load connected to the second terminal. A second current having a smaller value than an allowable value of the first current passed by the switch means is caused to flow between the third terminal and the reference potential, with one terminal being set as a reference potential. A power conversion device characterized in that the second current is synchronized with the first current. 2. In claim 1, a voltage across the switch means with respect to the reference potential inside the monolithic integrated circuit is a first voltage, and a voltage at the third terminal with respect to the reference potential is a second voltage. , the second voltage is synchronized with the first voltage, and the second voltage in the high level state is smaller than the first voltage also in the high level state. Device. 3. In claim 1, the withstand voltage or current capacity of a semiconductor element constituting the control circuit inside the integrated circuit is smaller than the withstand voltage or current capacity of a semiconductor element constituting the switch means. Further, the power conversion device is characterized in that the control circuit and the switch means are formed insulated and separated from each other in a semiconductor substrate, and the withstand voltage of the insulation separation is higher than the voltage of the external power supply. . 4. The power conversion device according to claim 3, wherein the point in time when the drive signal is generated and terminated, and the point in time when the second current is generated and terminated can be controlled separately. . 5. Claim 4, further comprising a detection means for detecting at least one of the first current or the temperature near the switch means, and the detection means transmits a detection signal to the control circuit, A power conversion device characterized in that when at least one of the first current or temperature becomes larger than a predetermined value, at least one of the first current or the second current is cut off.