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- Differential Signal Conditioning Circuit for Current and Voltage Measurement
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24 Oct 2014 4,052 views
This design provides a 4-channel signal conditioning solution for differential ADCs integrated into a microcontroller measuring motor current using fluxgate sensors. Also provided is an alternative measurement circuit with external differential SAR ADCs as well as circuits for high-speed overcurrent and earth fault detection. Proper differential signal conditioning improves noise immunity on critical current measurements in motor drives. This reference design can help increase the effective resolution of the analog-to-digital conversion, improving motor drive efficiency.
- Designed to measure all three phase motor currents along with DC link current through 6A Fluxgate Sensors (Scalable to 50A)
- Differential Signal Conditioning Circuit to interface Fluxgate Sensors with differential ADCs
- Measures current and voltage through integrated differential ADCs of TI Delfino™ F2837xD microcontroller with a provision to interface the signal conditioning circuit with External ADCs
- Two on-board 14-bit Dual Channel Simultaneous Sampling SAR ADCs with 4-wire SPI to interface with external motor controllers
- < 0.1% DC accuracy of Signal Conditioning Circuit
- Overload and Earth Fault Protections for each channels with < 100ns sensing delays