GXSC synchronous sampling ADC replaces AD7616 for analog sampling in high-voltage frequency converters

Analog signal acquisition is a very important function of high-voltage frequency converters. The controller collects feedback signals such as current and voltage for closed-loop control and alarm protection. High precision and real-time requirements are required here. Traditional ADCs have a high resolution of 12 bit unipolar and require an additional circuit for unipolar to bipolar conversion. Moreover, the measured accuracy is very low. This article mainly introduces the application of a GXSC 16 channel 16 bit ADC in frequency converters.

The frequency converter needs to sample the grid side machine, side voltage, and current. If there is synchronous transmission function, voltage sampling should also be performed. The GXSC ADC has a 16 bit ADC with 16 built-in sampling channels, supporting dual channel synchronous sampling with a sampling rate of 1MSPS, which can meet the requirements of multi-channel use. The chip is powered by a 5V power supply, which can support the conversion of true bipolar input signals of ± 10V/± 5V/± 2.5V. Each channel can achieve a signal-to-noise ratio of 89dB. By using on-chip oversampling mode, better signal-to-noise ratio performance can be achieved. The input port integrates a clamp protection circuit, which can withstand clamp voltages up to ± 22V.

The GXSC ADC is equipped with an input buffer and anti aliasing filter with a 1M Ω input impedance, making it easy to directly collect analog signals without the need to drive operational amplifiers or external bipolar power supplies. It also integrates a high-precision reference voltage generator and buffer that can be flexibly configured, which can simplify the PCB design of the data acquisition system. The advantages of this GXSC ADC product are as follows:

Product size, pins, functionality, and timing are compatible with reference products, supporting Pin To Pin in-situ replacement of AD7616

Single 5V power supply, supports converting true bipolar input signals of ± 10V/± 5V/± 2.5V

16 channels with independent channel selection input range

Software and hardware modes, flexible configuration, adaptable to a wider range of application scenarios

Support oversampling and on-chip self detection

ENOB: 14.5Bit (typical value)

SNR: 89dB (typical value)

SNDR: 88dB (typical value)

SFDR: -106dB (typical value)

INL: 1LSB (typical value)

DNL: 0.5LSB (typical value)

Working power consumption: 210mW (internal reference)

Working temperature: -55 ° C~125 ° C

GXSC ADC supports parallel mode or serial mode, configured through different connection modes of hardware pins. This function creates various connection conditions for the interface connection between the device and the microprocessor or DSP.