Motor Drive Semiconductor Circuit for Shared ADC Voltage Sensing
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Solution Overview
Problem
Current semiconductor devices for motor drive systems are costly due to large circuit sizes and increased chip area, which prolongs product testing and manufacturing times.
Innovation Solution
A semiconductor device with a switching circuit and operational amplifier configuration that allows multiple voltages to be measured using a single ADC, reducing circuit size and chip area by sharing an operational amplifier across multiple inputs, and incorporating a decoder to control switches for voltage switching and offset adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple ADCs are used to measure multiple voltages simultaneously, then measurement capability is improved, but device complexity and cost increase
Solution Approach 1:
A single ADC is designed to measure multiple voltages (VBUS, D+, D-) by sequentially switching between different input channels. The ADC shares a common input terminal that can be connected to different voltage sources through switching circuits, enabling one ADC to perform the work of multiple ADCs and reducing device complexity while maintaining measurement capability
Solution Approach 2:
The system dynamically switches the ADC input terminal between different voltage sources (VBUS, D+, D-) at different time periods. This dynamic switching allows the ADC to adaptively measure different voltages sequentially, transforming a static single-function ADC into a dynamic multi-function measurement device
2Adaptability or versatility
If multiple operational amplifiers are used for multiple inputs, then amplification capability is improved, but chip area increases
Solution Approach 1:
A single operational amplifier is designed to amplify multiple input signals (VBUS, D+, D-) by sequentially connecting different input terminals to its input end. The operational amplifier shares a common amplification function across multiple voltage sources, enabling one op-amp to replace multiple op-amps and significantly reducing chip area while maintaining amplification capability for all inputs
3Ease of manufacture
If circuit size is reduced to lower cost, then manufacturing cost decreases, but offset voltage influence increases
Solution Approach 1:
The system performs preliminary offset voltage measurement and correction by measuring the offset voltage when no input signal is applied, then subtracting this offset value from subsequent measurements. This preliminary action of measuring and correcting offset voltage ensures measurement precision is maintained even with a reduced circuit size and single ADC configuration
Solution Approach 2:
The system implements feedback by measuring the offset voltage and using this information to correct subsequent measurements. The offset voltage measurement feeds back into the calculation process, allowing the system to compensate for offset errors and maintain measurement accuracy despite circuit simplification
Data Source
AI summary
A semiconductor device includes first to fifth terminals, an amplification circuit including a first input end connectable to the first terminal and the third terminal, a second input end connectable to the second terminal and the fourth terminal, and an output end, and a switching circuit. The switching circuit is configured to switch between a first state in which the first input end is connected to the first terminal and insulated from the third terminal and the second input end is connected to the second terminal and insulated from the fourth terminal, and a second state in which the first input end is connected to the third terminal and insulated from the first terminal and the second input end is connected to the fourth terminal and insulated from the second terminal.