Application of the GXSC ADC as a Replacement for the AD7380 in Motor Control Current Detection

Current detection in motor controllers is used to monitor and control the motor’s operating status in real time, ensuring that the motor operates efficiently and stably. In motor drive controllers with a three-phase inverter bridge configuration, accurate detection of the motor’s phase currents enables precise control of motor torque and speed, while also monitoring whether the current exceeds the rated value to prevent faults such as motor overload or short circuits.

The motor control current detection system covers the entire process of motor startup, operation, and braking. Its core function is to collect motor stator current signals in real time, convert analog current signals into digital signals, and transmit them to the MCU/DSP control unit to perform operations such as speed regulation, torque control, and overcurrent/overload fault protection. GXSC’s four-channel, 16-bit, 4MSPS synchronous sampling ADC is specifically designed for high-end applications such as industrial control and motor control, and can replace the AD7380 in motor control current detection applications.

The GXSC ADC is powered by a 3.3V supply, achieves a maximum throughput rate of 4MSPS, and features core capabilities including dual-channel synchronous sampling, fully differential analog inputs, a built-in oversampling module, and a reference voltage source. It is housed in a compact QFN24 package with an operating temperature range of -40°C to +125°C, making it suitable for the miniaturization requirements of motor control and industrial-grade environments. Its differential analog inputs support a wide common-mode input voltage range, and sampling and conversion are triggered by the falling edge of the chip select signal.

Additionally, the GXSC ADC integrates an on-chip oversampling module, which effectively expands the dynamic range and reduces input noise in low-bandwidth applications. When the oversampling function is enabled, it can be configured for 18-bit high-precision mode. The voltage range for the reference input pin is 2.5 V to 3.3 V. The conversion process and data acquisition are implemented via a standardized control interface, facilitating integration with microprocessors or digital signal processors. Conversion results support two output modes: 1-wire serial output mode (suitable for low-speed applications) or 4-wire synchronous output mode (suitable for high-sampling-rate applications).

GXSC ADC Features:

• SNR: Typical value of 91.5 dB (VREF = 3.3 V)

• INL: Typical value of +1

• On-chip oversampling

• Supports 18-bit high-precision mode

• Out-of-range alarm indication

• High-speed serial interface

• QFN24 4mm x 4mm package

• Operating temperature range: −40°C to 125°C