Control circuit for semiconductor device having overheating protection function

a control circuit and semiconductor technology, applied in the direction of ohmic-resistance heating, instruments, heat measurement, etc., can solve the problems of large size, high cost of control circuits for semiconductor devices having an overheating protection function, and the progress of overheating of semiconductor elements. , to achieve the effect of small size, low cost and simple circui

Active Publication Date: 2007-09-13
YAZAKI CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0015]According to the invention, neither a control unit that is dedicated to monitoring of the semiconductor device having an overheating protection function nor an interconnection extending from the semiconductor device having an overheating protection function to such a control unit is necessary. As a result, the circuit can be made simple and small in size and hence the control circuit for a semiconductor device having an overheating protection function can be produced at a low cost. Further, deterioration of the semiconductor element due to overheating can be minimized to enhance the reliability of the semiconductor element. Furthermore, even if the current detecting circuit outputs a detection signal due to disturbance noise, the drive circuit keeps the drive voltage at the prescribed voltage, which prevents trouble that no drive current flows through a load.
[0016]As such, the invention can provide a control circuit for a semiconductor device having an overheating protection function which has high reliability that the probability of breaking of the semiconductor element is very low and which operates reliably, though it is simple in configuration. Therefore, where the semiconductor device having an overheating protection function is used for driving of a vehicle lamp, for example, occurrence of a fire in the vehicle can be prevented.

Problems solved by technology

This results in problems that the circuit is complex and large in size and hence the control circuit for the semiconductor device having an overheating protection function is expensive.
This results in a problem that deterioration due to overheating of the semiconductor element progresses though slightly.
Furthermore, in the above conventional control circuit for the semiconductor device having an overheating protection function, a control may be performed in such a manner that the supply of the PWM control signal to the semiconductor element is stopped because the control means operates erroneously due to disturbance noise though the semiconductor element is not overheated and cut off.
There is a problem that this no load current comes to flow through a load and, if the load is a lamp, the lamp is turned off.

Method used

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  • Control circuit for semiconductor device having overheating protection function
  • Control circuit for semiconductor device having overheating protection function
  • Control circuit for semiconductor device having overheating protection function

Examples

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embodiment 1

[0024]FIG. 1 is a block diagram showing the configuration of a control circuit for a semiconductor device 4 having an overheating protection function according to a first embodiment of the present invention. The control circuit of the semiconductor device 4 having an overheating protection function of this example generally includes an OR gate 1, a current detecting circuit 2, a drive circuit 3, and the semiconductor device 4 having an overheating protection function.

[0025]The OR gate 1 supplies the drive circuit 3 with a logical value (H-level of L-level) that is the OR of a PWM signal (H-level of L-level) supplied externally and a detection signal (H-level of L-level) supplied from the current detecting circuit 2. The current detecting circuit 2 outputs an H-level detection signal VDEC if a drive current that flows from a VP power source to the semiconductor device 4 having an overheating protection function via the drive circuit 3 exceeds a preset threshold current.

[0026]The driv...

embodiment 2

[0059]FIG. 4 is a circuit diagram showing the configuration of a control circuit for a semiconductor device 4 having an overheating protection function according to a second embodiment of the invention. In FIG. 4, components having corresponding components in FIG. 2 are given the same reference symbols as the latter and will not be described. The control circuit for the semiconductor device 4 having an overheating protection function shown in FIG. 4 is different from that shown in FIG. 2 only in that the lamp 11 is provided between the VB power source and the drain terminal D of the semiconductor device 4 having an overheating protection function. The control circuit for the semiconductor device 4 having an overheating protection function of this example operates approximately in the same manner as in the first embodiment and hence its operation will not be described.

[0060]As described above, according to the second embodiment of the invention, the invention can be applied to the de...

embodiment 3

[0061]FIG. 5 is a circuit diagram showing the configuration of a control circuit for a semiconductor device 6 having an overheating protection function according to a third embodiment of the invention. In FIG. 5, components having corresponding components in FIG. 2 are given the same reference symbols as the latter and will not be described. The control circuit for the semiconductor device 6 having an overheating protection function of this example is a device (high-side switching device) in which a p-channel MOSFET 34 is disposed upstream of a lamp 11 as a load. The control circuit for the semiconductor device 6 having an overheating protection function of this example is incorporated in an automobile, for example. In FIG. 5, the load is the lamp 11 that is used in, for example, a winker (flasher) for producing a signal indicating a turn.

[0062]In FIG. 5, a resistor R31 and a pnp transistor Q11 constitute an OR gate. The pnp transistor Q11 and resistors R32 and R33 constitute a curr...

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PUM

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Abstract

A control circuit includes a drive circuit which applies a drive voltage to a semiconductor device having an overheating protection function according to an externally supplied signal; and a current detecting circuit which outputs a detection signal when a drive current flowing through the semiconductor device exceeds a predetermined threshold current. The semiconductor device incorporates a semiconductor element, a temperature detecting circuit for detecting temperature increase of a chip, and an interrupting circuit for interrupting an input to the semiconductor element according to a detection output of the temperature detecting circuit. The drive circuit turns off the semiconductor element and changes the drive voltage to a predetermined voltage so that the drive current exceeds the threshold current when the interrupting circuit interrupts an input to the semiconductor element, and keeps the drive voltage at the predetermined voltage while the detection signal is output from the current detecting circuit.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to a control circuit for a semiconductor device having an overheating protection function for preventing breaking, due to overheating, of a power semiconductor element that is used for driving a vehicular lamp, for example.[0002]A control circuit for a semiconductor device having an overheating protection function is known which includes a semiconductor device having an overheating protection function, an output state detecting means, and a control means. The semiconductor device having an overheating protection function is such that a semiconductor element such as a MOSFET, a temperature detecting circuit, a latch circuit, and a gate interrupting circuit are incorporated in one chip. The temperature detecting circuit detects temperature increase of the chip and supplies a detection output to the latch circuit. The latch circuit latches the detection output of the temperature detecting circuit. Controlled by the output o...

Claims

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Application Information

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IPC IPC(8): H05B1/02
CPCH01L27/0248H01L2924/0002H01L2924/00
InventorYABE, HIROO
OwnerYAZAKI CORP