Microphone Soft Clipping Circuit Temperature Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Previous microphone clipping circuits suffer from signal distortion due to temperature variations, as they rely on diodes with large temperature coefficients, leading to inconsistent clipping points and user dissatisfaction.
Innovation Solution
A soft clipping circuit with temperature compensation is implemented, where the maximum signal drawn by a buffer remains constant across a temperature range, using a configuration of diodes that adjusts the clipping point to maintain consistent signal processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diodes are used in clipping circuits, then signal clipping function is achieved, but temperature stability deteriorates due to large temperature coefficient
Solution Approach 1:
The patent changes the electrical parameters of the circuit by introducing a temperature-compensating diode with opposite temperature coefficient characteristics to counterbalance the temperature effects of the clipping diodes. This parameter change approach maintains the clipping function while achieving temperature stability.
Solution Approach 2:
The patent introduces a compensating diode as an intermediary element that mediates the temperature effects on the clipping circuit. This compensating diode acts as a mediator to offset the temperature coefficient variations and maintain consistent clipping points across temperature ranges.
2Power
If signal magnitude is increased, then output signal strength is improved, but signal distortion increases due to ASIC limitations
Solution Approach 1:
The patent applies preliminary action by performing soft clipping on the signal before it reaches the ASIC buffer. This pre-processing action prevents the signal from exceeding the ASIC's linear operating range, thereby avoiding distortion while maintaining strong output signals.
Solution Approach 2:
The patent converts the potential harmful effect of large signal magnitudes into a benefit by using the clipping diodes to deliberately limit the signal in a controlled manner. This controlled limitation prevents harmful distortion in the ASIC while maintaining overall signal strength and quality.
Data Source
AI summary
An apparatus includes a microelectromechanical system (MEMS) device having a diaphragm and a back plate; a clipping circuit coupled to the MEMS device, wherein the clipping circuit is configured to clip an output signal of the MEMS device so that the maximum signal drawn by a buffer is substantially constant over a temperature range; and an integrated circuit coupled to the clipping circuit, the integrated circuit including the buffer.