Semiconductor Temperature Protective Circuit with Gradual Drive Limiting
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Solution Overview
Problem
Conventional semiconductor integrated circuit units lack effective pre-emptive measures to prevent abnormal heat generation and suffer from sharp output shutdowns, leading to potential IC breakage and logic oscillations in temperature protective circuits.
Innovation Solution
A temperature protective circuit with a heat generation detecting section and a limiting signal producing section that gradually or stepwise limits the drive of a load's current or torque based on monitored temperature, preventing abnormal heat generation and ensuring safe shutdown without sudden output termination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the conventional temperature protective circuit waits until the chip temperature reaches the threshold temperature to shut down, then the detection accuracy is improved, but the abnormal heat generation cannot be prevented and the chip temperature easily increases
Solution Approach 1:
The patent applies preliminary action by introducing a preliminary protective operation that activates before the chip temperature reaches the threshold temperature. The control circuit detects temperature rise trends and performs preliminary protective operations (such as reducing drive current or torque) when the temperature approaches but has not yet reached the threshold, thereby preventing abnormal heat generation before it occurs rather than merely detecting it after the threshold is reached.
2Reliability
If the conventional temperature protective circuit performs sharp shut-down operation at abnormal heat generation, then the IC breakage is prevented, but noise or surge generation occurs and various discrepant conditions are introduced
Solution Approach 1:
The patent applies beforehand cushioning by implementing a gradual reduction of drive current or torque through the limiting signal producing section before complete shut-down occurs. This cushioning approach reduces the abruptness of the shut-down operation, thereby preventing IC breakage while minimizing the generation of noise and surges that would result from sudden output termination.
3Measurement precision
If the temperature protective circuit is provided near the subject of overheat monitoring to improve detection sensibility, then the detection accuracy is improved, but the logic states are frequently repeated causing logic oscillating state
Solution Approach 1:
The patent applies feedback by implementing a control circuit that continuously monitors the chip temperature and adjusts the drive current or torque based on the detected temperature and its rate of change. This feedback mechanism provides hysteresis and damping effects that stabilize the logic states, preventing frequent switching and logic oscillating states while maintaining high detection sensibility through proximity placement of the temperature sensor.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively limits abnormal heat generation, prevents IC breakage, and reduces noise or surge generation, enabling safe and reliable operation by gradually controlling the drive current or torque level as temperature thresholds are reached.
Implementation Method 1
the conventional temperature protective circuit generally has been configured to produce a temperature protective signal by utilizing characteristics in that the Vf (forward dropping voltage) of a bipolar transistor or a diode fluctuates depending on the ambient temperature thereof
Data Source
AI summary
A temperature protective circuit of the semiconductor integrated circuit unit of the present invention is configured such that the circuit includes a heat generation detecting section for detecting a monitored temperature and a limiting signal producing section for limiting continuously or stepwise the drive of a load (for example, the upper limit of drive current) according to the above-mentioned monitored temperature, after the above-mentioned monitored temperature exceeds a first threshold temperature, based on the detection results of the above-mentioned heat generation detecting section. With such a configuration, an abnormal heat generation of a subject of overheat monitoring can be previously limited to perform a more safely temperature protective operation.