WO2015104921A1

WO2015104921A1 - Onboard electronic control device

Info

Publication number: WO2015104921A1
Application number: PCT/JP2014/081926
Authority: WO
Inventors: 修一宮岡; 小林　良一; 金川　信康
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2014-01-09
Filing date: 2014-12-03
Publication date: 2015-07-16
Also published as: JPWO2015104921A1

Abstract

The purpose of the present invention is to provide, at a low cost, a multifunctional integrated circuit (IC) that can continue stable operations with the exception of the part that is affected when an abnormality has occurred in a pre-driver circuit. The multifunctional semiconductor device (1), which includes a pre-driver circuit, is provided with current interruption circuits (25, 32). When a large current has flowed into the pre-driver circuit as a result of a short-circuit fault due to junction breakdown or dielectric breakdown that is caused by noise applied to any of the switching components (20, 21, 35, 36) of the pre-driver circuit (14), the current flowing in the faulty pre-driver circuit (14) is interrupted by the current interruption circuits (25, 32), preventing a drop in the power supply voltage. In such case, the output potential of the pre-driver is fixed to a low level at the high side and to a high level at the low side to render the circuit inactive.

Description

In-vehicle electronic control unit

The present invention relates to a vehicle-mounted control device including a driver for driving a load and a pre-driver in the preceding stage, and a response to a failure of the drive circuit.

As background art in this technical field, for example, there is JP 2012-157154. This publication describes that a failure is detected at a corresponding location and the current is cut off. As background arts in this technical field, there are also JP 2012-157154 A and JP 2010-098907 A.

JP 2012-158318 A JP 2012-157154 A JP 2010-098907 A

In recent years, in-vehicle electronic control devices have integrated electronic circuits in the in-vehicle electronic control devices such as injectors, igniters, and solenoids into silicon chips from the viewpoints of the number of parts, cost reduction, and downsizing. It has been studied and put into practical use. Conventionally, when these drive circuits are short-circuited due to a failure, a short-circuit current flows, but the current cut-off means is not provided. An overcurrent detection circuit is provided, and if an overcurrent is detected, the operation of the drive circuit is often stopped and the current is not cut off.

Also, as disclosed in Patent Document 1, in recent years, an approach for detecting a failure at a corresponding portion and cutting off the current has been implemented. However, when the gate of the MOS transistor is destroyed, an abnormal current from the previous circuit is also assumed. Further, since the predriver output is not fixed, there is a problem that the operation of the driver circuit becomes unstable.

If the overcurrent continues to flow, the integrated circuit will burn out and all functions implemented as an IC will be lost. In that case, it leads to a serious accident. On the other hand, as a market requirement, it is strongly demanded that a normal circuit continues to operate by disconnecting only a fault location (cutting off a current path).

In addition, in the current interruption method shown in Patent Document 2, when the gate of the MOS transistor is broken down, an abnormal current from the previous circuit is assumed, but there is a problem that it cannot be dealt with. Furthermore, since the predriver output is not fixed, there is a problem that the operation of the driver circuit becomes unstable.

Therefore, an object of the present invention is to provide a low-cost multi-function IC capable of continuing stable operation of functions other than the corresponding defective portion even when an abnormality occurs in the pre-driver circuit.

An object of the present invention is to have an overcurrent detection circuit and a current cut-off circuit as an example, detect an overcurrent, and cut off the current path. Further, when the current is interrupted, this can be achieved by fixing the pre-driver output to Lo or Hi so that the driver circuit does not cause unstable operation due to input floating.

According to the present invention, even when an abnormality occurs in the pre-driver circuit, it is possible to provide a multi-function IC capable of continuing stable operation of functions other than the corresponding defective portion at a low cost.

It is a block diagram which shows the structure of one Embodiment of the multifunctional semiconductor device containing the predriver circuit by this invention. FIG. 2 is a block diagram showing a configuration example of a current interrupt circuit according to the first embodiment of the present invention. It is a block diagram which shows the structural example of the multifunctional semiconductor device containing the predriver circuit by the 2nd Embodiment of this invention. It is a block diagram which shows the structural example of the multifunctional semiconductor device containing the predriver circuit by a prior art.

Hereinafter, examples will be described with reference to the drawings.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a block diagram showing a configuration of an embodiment of a multifunction semiconductor device including a pre-driver circuit according to the present invention. 1 is different from the conventional device of FIG. 4 in that a current cut-off switch 25 is provided between the high-side push-pull circuit 19 and the booster circuit 5, and the low-side push-pull circuit of each phase. The difference is that a current cut-off switching element 32 is provided between the power supply circuit 18 and the power supply circuit 4.

The feature of the present invention is that, as shown in FIG. 1, the current

interrupt switching elements

25 and 32 and the potential fixing switching elements 29 and 39 are provided in a multi-function IC including a pre-driver circuit. The current cut-

off switch elements

25 and 32 are provided when the

semiconductor switch element

20, 21, 35 or 36 of the pre-driver circuit 14 is short-circuited due to junction breakdown or dielectric breakdown and a large current flows. The current flowing through the pre-driver circuit 14 is cut off. As a result, fusing / burning failure due to a large current can be prevented, and the boosted voltage output from the booster circuit 5 or the power supply voltage supplied from the power supply circuit 4 can be prevented from decreasing. As a result, other driver boosted voltages or power supply voltages are not affected, and normal output is possible.

Hereinafter, embodiments of the current

interrupting switching elements

25 and 32 of FIG. 1 will be described in detail with reference to FIGS.

FIG. 2 is a block diagram showing a configuration example of the current interruption control circuit 11 according to the first embodiment of the present invention. As shown in FIG. 2, the current cutoff control circuit 11 of this embodiment includes

operational amplifiers

45 and 46,

filter circuits

47 and 48, and a logic circuit 14. Here, the current cutoff switching element 25 is shown as a representative example, but the current cutoff switching element 32 also has the same configuration.

The normal operation is as follows.

In the case of Hi output, the high-side semiconductor switch element 27 is turned on and the low-side semiconductor switch element 42 is turned off. At this time, the output of the high-side push-pull circuit 19 is controlled to Hi and the output of the low-side push-pull circuit 18 is controlled to Lo.

In the case of Lo output, the high-side semiconductor switch element 27 is turned off and the low-side semiconductor switch element 42 is turned on.
At this time, the output of the high-side push-pull circuit 19 is controlled to Lo and the output of the low-side push-pull circuit 18 is controlled to Hi.

When an abnormal current occurs, it is detected by the short circuit /

open detection circuits

93 and 94. The short-circuit / open-

circuit detections

93 and 94 convert the detection current into a detection voltage and output it to the

operational amplifiers

45 and 46. The detected voltage is input to the non-inverting input side of the

operational amplifiers

45 and 46.

The

operational amplifiers

45 and 46 compare the current detection voltage from the short-circuit / open-

circuit detection circuits

93 and 94 input to the non-inverting input side with the reference voltage input to the inverting input side, and a comparator corresponding to the comparison result The output is output to the

filter circuits

47 and 48. The comparator outputs that have passed through the

filter circuits

47 and 48 are logically ORed with the arithmetic processing unit signal by the logic circuit 14 and send out a fault diagnosis output 24. The occurrence of an abnormality can be detected by outputting the failure diagnosis output 24. The detected abnormality is transmitted to the arithmetic processing unit 10 by the SPI signal, and abnormality processing is performed.

The fault diagnosis output 24 turns off the current cutoff switching element 25 of the high-side push-pull circuit and the current cutoff switching 32 of the low-side push-pull circuit, and a through current from the booster circuit 5 to the ground via the boosted voltage supply wiring 7 The through current flowing from the power supply circuit 4 to the low-side driver 18 is cut off.
In this case, the through current includes the current flowing between the source and drain of the

switching elements

20, 21, 35, and 36 and the push-

pull circuits

22 and 37 of the previous stage via the gate electrodes of the

switching elements

20, 21, 35 and 36. Some of them flow into the source electrode. In order to cut off these through-currents, a current cut-off switching element 25 is arranged in the power supply section of the high side push-pull circuit 19 and its preceding push-pull circuit, and the low side push-pull circuit 18 and its previous push-pull circuit 37. The current interrupting switching element 32 is disposed in the GND power supply section.

電位 Turn on the potential fixing switching elements 29 and 39, and fix the high-side driver output to Lo and the low-side driver output to Hi so that the high-side and low-side pre-driver outputs that are cut off are not unstable.

Further, the current interrupt control circuit 11 can also control the on / off of the current

interrupt switching elements

25 and 32 by the arithmetic processing unit signal output from the arithmetic processing unit 10. That is, it is determined in the arithmetic processing device 10 whether or not a predetermined current interruption condition is satisfied, and when it is determined that the current interruption condition is satisfied, an arithmetic processing device signal is output from the arithmetic processing device 10 to the current interruption control circuit 11. By doing so, the current supply from the power supply circuit 4 to the pre-driver circuit 14 can be forcibly cut off. The arithmetic processing unit 10 can perform on / off control of the current

cutoff switching elements

25 and 32 by the arithmetic processing unit signal even when detecting an abnormality in the driver circuit.

As described above, by interrupting the through current at the time of the short-circuit failure by the current interrupt control circuit 11, other functions due to the junction / dielectric breakdown of the

switching elements

20, 21, 35, 36 in the pre-driver circuit 14 are achieved. Adverse effects can be reduced. As a result, even when an abnormality occurs, stable operation can be continued except for the function.

According to the 1st Embodiment of this invention demonstrated above, there exist the following effects.
(1) The multi-function semiconductor device 3 including a pre-driver function is provided for controlling the operations of the high-side semiconductor switch element 27 and the low-side semiconductor switch element 42 and the high-side semiconductor switch element 27 and the low-side semiconductor switch element 42. The predriver circuit 14, the power supply circuit 4 that supplies current to the predriver circuit 14, the arithmetic processing device 10 that calculates and outputs a control signal, and a drive signal based on the control signal output from the arithmetic processing device 10 , The

drive circuits

22 and 37 for controlling the operations of the high-side push-pull circuit 19 and the low-side push-pull circuit 18 based on the drive signal output from the logic circuit 15, and the current is a predetermined value. The short circuit /

opening detection circuits

93 and 94 for detecting the above and the booster circuit 5 to pre-dry Current cut-off switching element 25 that cuts off the supply of current to circuit 14, current cut-off switching element 32 that cuts off the current path from low-side push-pull circuit 18 to the GND potential, short-circuit / open-

circuit detection circuits

93 and 94, and current cut-off control circuit 11. With this configuration, it is possible to provide the multifunction semiconductor device 3 that can continue stable operation even when an abnormality occurs at a low cost.
(2) The pre-driver circuit 14 includes a high-side push-pull circuit 19 provided corresponding to the high-side semiconductor switch element 27 and a low-side push-pull circuit 18 provided corresponding to the low-side semiconductor switch element 42. Current

cutoff switching elements

25 and 32 cut off the supply of current to both the high-side push-pull circuit 19 and the low-side push-pull circuit 18, turn on the potential fixing elements 29 and 39, and output the high-side driver output. Fixed low side driver output to high level.

Thus, the operations of the high-side push-pull circuit 19 and the low-side push-pull circuit 18 are appropriately controlled by the high-side push-pull circuit 19 and the low-side push-pull circuit 18, respectively. When an abnormality occurs in at least one of the circuits 18, the current supply to the circuit is cut off, and other functions are not adversely affected.

(3) The current interruption control circuit 11 changes the output voltage of the voltage follower circuit by the

operational amplifiers

45 and 46 when the magnitude of the current detected by the

current detection circuits

93 and 94 is equal to or greater than a predetermined value. 24 is output. The failure diagnosis signal 24 turns off the current

cutoff switching elements

25 and 32 to cut off the supply of current from the power supply circuit 4 and the booster circuit 5 to the pre-driver circuit 14. Thereby, it is possible to reliably detect an abnormality occurring in the pre-driver circuit 14 and cut off the current supply.

Further, the current interruption control circuit 11 notifies the arithmetic processing unit 10 that an abnormality has occurred through an SPI (serial peripheral interface) circuit or an MSC (microsecond channel) circuit. As a result, it is possible for the entire system to grasp that an abnormality has occurred in the pre-driver circuit 14, and to take measures such as warning to the user as necessary.

(4) The multifunctional semiconductor device 3 integrates a plurality of circuits including at least the pre-driver circuit 14, the logic circuit 11, the various drive circuits 51, the power supply circuit 4, the booster circuit 5, and the current cutoff control circuit 11. Thereby, size reduction and cost reduction of a motor control apparatus etc. can be achieved.

A current blocking method for the high-side semiconductor switch element 27 and the low-side semiconductor switch element 42 according to the second embodiment of the present invention will be described with reference to FIG.

When an abnormality occurs in the high-side semiconductor switch element 27 and the low-side semiconductor switch element 42 and an overcurrent flows, the abnormality is detected by the short-circuit detection circuit 52. The abnormality detection signal 53 is transmitted to the arithmetic processing device 10. The arithmetic processing unit 10 outputs a current cutoff signal 54, turns off the high-side current source switch element 28 via the boost driver circuit 61, and causes the current cutoff control circuit 11 to output an arithmetic processing unit signal through the SPI circuit or the MSC circuit. 55 is sent out. As shown in the first embodiment, the current cutoff control circuit 11 cuts off the current of the pre-driver circuit 14 and fixes the output to low level / high level.

Using a serial communication between the microcontroller and the driver IC, the driver IC has a control unit that performs diagnostic control of the driver IC. When a failure is detected, the circuit is immediately deactivated. The occurrence of serious defects such as fusing can be prevented. Therefore, it can be applied to an apparatus that requires high reliability.

DESCRIPTION OF SYMBOLS 3 Semiconductor device 4 Power supply circuit 5 Booster circuit 6 Power supply wiring 7 Boost voltage supply wiring 8 Battery voltage 9 Ground 10 Arithmetic processing device 11 Current interruption control circuit 12 Short circuit / open detection signal 13 Short circuit / open detection signal 14 Pre-driver circuit 18 Low Side push-pull circuit 19 High-side push-pull circuit 20 Semiconductor switch element 21 Semiconductor switch element 22 Drive circuit 23 Semiconductor switch element 24 Fault diagnosis output 25 Current cut-off switching element 26 Pre-driver output wiring 27 High-side semiconductor switch element 29 Semiconductor switch element 32 Current cut-off switching element 33 Semiconductor switch element 34 Low-side push-pull circuit 35 Semiconductor switch element 36 Semiconductor switch element 37 Drive circuit 39 Semiconductor switch element 41 Pre-driver output wiring 42 Low-side semiconductor switching element 45 Op-amp 46 Op-amp 47 Filter circuit 48 Filter circuit 49 Logic circuit 51 Driver circuit 52 Short-circuit detection circuit 53 Short-circuit detection signal 54 Current cut-off signal 55 Operation processing signal 61 Boost driver 62 Boost driver signal 93 Short-circuit / open detection circuit 94 Short-circuit / open detection circuit

Claims

A driver circuit comprising a MOSFET for driving a load;
An in-vehicle control device including a pre-driver circuit in the preceding stage,
The pre-driver circuit includes current detection means,
When the pre-driver circuit fails, the abnormal current portion of the corresponding circuit section is cut off, and the output of the pre-driver circuit is fixed to Low or Hi so that the output of the driver circuit becomes inactive. In-vehicle electronic control device.
A driver circuit comprising a MOSFET for driving a load;
An in-vehicle control device including a pre-driver circuit in the preceding stage,
The driver circuit comprises an abnormal current detection means,
When the driver circuit fails, the abnormal current portion of the corresponding circuit unit is cut off, and the output of the pre-driver circuit is fixed to Low or Hi so that the output of the driver circuit becomes inactive. A vehicle-mounted electronic control device.
The in-vehicle control device according to claim 1,
The driver circuit comprises an abnormal current detection means,
When the pre-driver circuit or the driver circuit fails, the abnormal current portion of the corresponding circuit section is cut off, and the output of the pre-driver circuit is fixed to Low or Hi so that the output of the driver circuit becomes inactive. An in-vehicle electronic control device.
The in-vehicle control device according to claim 1,
The driver circuit comprises an abnormal current detection means,
When the pre-driver circuit fails, the abnormal current portion of the corresponding circuit section and the current path from the previous circuit are cut off together, and the output of the pre-driver circuit is set so that the output of the driver circuit is inactive. A vehicle-mounted electronic control device characterized by being fixed to Low or Hi.
The in-vehicle control device according to claim 1,
A semiconductor integrated device in which the pre-driver circuit, the power supply circuit, and the driver circuit are integrated into one chip.