Op Amp Over-Current Protection Circuit
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Solution Overview
Problem
Existing operation amplification circuits face challenges in controlling operating temperature, leading to high power consumption and potential damage due to lack of effective over-current protection mechanisms that can adapt to varying power supply voltages and signal frequencies.
Innovation Solution
An operation amplification circuit with an over-current protection unit that detects temperature and adjusts output current using a temperature control current, limiting power consumption and preventing excessive temperature by correlating the temperature control current with the operating temperature, ensuring efficient operation and preventing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the gate-source voltages of transistors P0 and N0 are limited to set values when they reach a certain value, then the operating temperature and power consumption are controlled, but the on currents of transistors P0 and N0 are limited even when the power supply voltage is small and the operating temperature is not high, reducing output efficiency and drive capability
Solution Approach 1:
The patent changes the control parameter from fixed gate-source voltage limiting to dynamic output current limiting based on temperature. The over-current protection unit dynamically adjusts the output current magnitude according to the detected operating temperature, rather than fixing the gate-source voltages. This allows the system to maintain high output efficiency when temperature is low while effectively controlling temperature when it rises, resolving the contradiction between temperature control and output efficiency.
2Temperature
If the gate-source voltages of transistors P0 and N0 are limited to achieve the purpose of limiting the output current, then the operating temperature of the operation amplification circuit is controlled, but the frequency of the input signal cannot be considered, causing unnecessary current limitation at low frequencies and insufficient current limitation at high frequencies
Solution Approach 1:
The patent implements dynamic current limitation by using the over-current protection unit to continuously monitor operating temperature and dynamically adjust the output current magnitude in real-time based on temperature conditions and signal frequency characteristics. This dynamic approach replaces the static gate-source voltage limiting method, enabling the system to adapt to varying signal frequencies and power supply voltages while maintaining effective temperature control, thus improving adaptability across different operating conditions.
Data Source
AI summary
Disclosed is an operation amplification circuit and an over-current protection method therefor. The operation amplification circuit comprises: a control unit, configured to generate an output control signal according to an input signal and an output signal; an output unit, configured to generate an output current under control of the output control signal, wherein the output unit comprises an output capacitor which is charged or discharged by the output current to generate the output signal; an over-current protection unit, obtaining a temperature control current according to an operating temperature of the operation amplification circuit, wherein when the operating temperature is greater than or equal to a predetermined temperature, the temperature control current is positively correlated with the operating temperature, and the over-current protection unit adjusts the output control signal according to the temperature control current to limit the output current.