Motor current detection system solution based on ADSP-CM408 and AD7403

The current loop is the core link of motor control. Shijian's EPSH-MPC development platform covers all phase current detection functions in motor applications, supports the design of motor current loops of different power levels, and completely and accurately realizes the current flow of the current loop. Acquisition, PWM signal modulation, on-chip ADC signal link conditioning and acquisition, and encoder position signal acquisition provide open-loop control of the motor. By providing complete hardware design and graphical host computer software, we can help customers Quickly assess performance and shorten design cycles.

For small and medium power motor applications, the EPSH-MPC development platform provides current sampling of the isolated analog-to-digital converter AD7403 . The external current loop is converted into a corresponding shunt voltage through a shunt resistor and input to the voltage test terminal of the AD7403 . The AD7403 outputs according to the clock signal given by CM408F . ADC bit stream, CM408F enables the built-in SINC filter on the input bit stream to calculate the corresponding 16-bit ADC value, and stores the data into the corresponding ring queue through DMA. The host computer software can use the UART-USB port to Or obtain the display of data samples through the RS485 port, you can intuitively see the acquisition effect of AD7403, and the collected data can be stored in an excel table to facilitate corresponding analysis of the data.

For high-power motor applications, the CM408F-MPC development platform provides input based on the high-performance 16-bit SAR ADC on-chip ADSP-CM408 . Through the corresponding signal conditioning circuit, it can achieve 0-2.5V signal input and support Hall devices. +SAR ADC application.

The CM408F-MPC development platform provides a set of digitally isolated PWM signal outputs. The frequency and duty cycle of the PWM signal can be changed by adjusting the adjustable resistor. During the adjustment process, you can connect an oscilloscope through the corresponding interface to observe the changes in the corresponding signals.

The CM408F-MPC development platform provides encoder test position information through the A/B/I signal interface. This interface also uses digital isolation. Through the automatic cycle collection of the host computer, the current position information can be observed in real time. Customers can use this information Speed ​​is calculated by M/T algorithm.

The PC software is graphically designed for motor current loop applications. It has waveform display, collected data display, encoder display, and PWM dead zone time setting functions.