GXSC ADC Replaces AD7656 in Power Quality Monitoring

With the widespread adoption of renewable energy and power electronics equipment today, power quality monitoring ensures grid safety, equipment stability, and the reliability of power supply. Power quality issues such as voltage sags, excessive harmonics, three-phase imbalance, and frequency fluctuations not only cause precision equipment to shut down and accelerate the aging of electrical equipment but may also increase energy loss. Power quality monitoring is a critical safeguard for the safe and stable operation of the power grid, the efficient grid integration of renewable energy, and the continuity of industrial production.

The GXSC ADC is specifically designed for multi-channel, high-precision data acquisition scenarios, meeting the sampling requirements for multi-phase voltage and current. The chip features low input noise and a conversion rate of up to 250 kSPS per channel, enabling precise capture of subtle voltage and current fluctuations as well as higher-order harmonic signals in the power grid. It supports both parallel and serial modes, configurable via different hardware pin connections, providing versatile interfacing options for connecting the device to microprocessors or DSPs.

The GXSC ADC operates on a single 5V power supply while supporting true bipolar input signals ranging from ±10V to ±5V. Through built-in calibration algorithms, the product significantly enhances both dynamic and static performance. In terms of dynamic performance, the product achieves a signal-to-noise ratio (SNR) of up to 90 dB and a spurious frequency dynamic range (SFDR) of 100 dB. In terms of static performance, it features a bipolar zero-level error as low as ±2 LSB and linearity better than 1 LSB.

GXSC ADC Performance Advantages:

 Supports pin-to-pin replacement for the AD7656

 The product is pin-to-pin, feature-to-feature, and timing-compatible with the reference product. It operates on a single 5V supply and is compatible with ±15V power pins, making it convenient for applications.

 Higher signal-to-noise ratio and higher linearity

 Lower bipolar zero-point error and lower full-scale error

 Higher channel isolation

 ENOB: 14.5 bits (typical)

 SNR: 89.5 dB (typical)

 SNDR: 89 dB (typical)

SFDR: -103 dB (typical)

THD: -100 dB (typical)

INL: ±1 LSB (typical)

DNL: ±0.5 LSB (typical)

Operating Power: 110 mW (internal reference)

Operating Temperature: -55°C to +125°C

 Available in a 64-pin QFP package, with both ceramic and plastic package options

To simplify PCB design for data acquisition systems, the GXSC ADC incorporates an input buffer with 1 MΩ input impedance and an anti-aliasing filter for direct analog signal acquisition. It also integrates a highly configurable, high-precision reference voltage generator and buffer.