GXSC eight channel 16 bit 200kSPS synchronous sampling ADC GX7606 replaces AD7606 for motor three-phase current monitoring scheme

In the motor drive system, three-phase current is mainly used for real-time monitoring to achieve closed-loop control, overcurrent protection, and fault diagnosis of the motor. Whether it is variable frequency speed regulation of industrial motors or drive control of new energy vehicles, it is necessary to accurately grasp the magnitude and balance state of three-phase current. This article mainly introduces an eight channel 16 bit 200kSPS synchronous sampling analog-to-digital converter GX7606 replacing AD7606 for current monitoring of motor three-phase.

The current of a three-phase motor has a strict phase relationship, and during monitoring, it is necessary to ensure that the sampling time of the A, B, and C three-phase currents is completely synchronized. The analog-to-digital converter GX7606 is equipped with eight 16 bit fast and low-power successive approximation ADCs, supporting synchronous sampling of eight channels, and the conversion rate of each channel ADC is as high as 200kSPS. GX7606 only uses a 5V power supply to support the conversion of true bipolar input signals of ± 10V and ± 5V.

In order to simplify the PCB design of the data acquisition system, GX7606 is equipped with an input buffer with a 1M Ω input impedance and an anti aliasing filter, which facilitates direct acquisition of analog signals from the motor. In order to provide stable and accurate voltage output that is not affected by temperature, load, and power supply voltage changes, GX7606 integrates a high-precision reference voltage generator and buffer that can be flexibly configured.

The key performance of GX7606 is as follows:

8 independent ADCs

True bipolar analog input

Input signal range: ± 10V, ± 5V

Conversion rate: 200kSPS

Low power consumption: 108mW (internal reference, 200kSPS, 5V power supply)

On chip reference voltage source and buffer

Parallel and serial interface modes

High speed serial interface compatible with SPI interface protocol

Analog input channel provides 7kV ESD rated value

64 pin LQFP package and 64 pin CQFP package

GX7606 supports parallel or serial mode and can be configured through different connection modes of hardware pins. This feature creates multiple connection conditions for the interface connection between the chip and the microprocessor or DSP.