Applications of the GXSC ADC (Compatible with the AD7656) in Power System Measurement and Control

As smart grids undergo digital and intelligent upgrades, power system measurement and control devices ensure the safe and stable operation of the power grid. These devices primarily rely on high-precision analog signal acquisition to enable real-time monitoring of key parameters such as grid voltage, current, and frequency. Due to the complex operating conditions of power grids—characterized by transient fault disturbances, strong electromagnetic interference, and rapid signal transients—the GXSC 6-channel 16-bit synchronous sampling analog-to-digital converter is specifically tailored for industrial measurement and control as well as power protection applications. With its robust overall performance, it fully meets the requirements for high-precision metering and control in the power sector.

The GXSC ADC integrates six independent ADC sampling cores into a single chip and supports a hardware-based synchronous sampling mechanism, enabling the simultaneous acquisition of six core signals—three-phase voltage and three-phase current—in a single operation, with minimal phase deviation between channels and fully aligned timing. Equipped with a 16-bit precision successive approximation quantization core, it features extremely low quantization error and a wide dynamic range, enabling precise capture of faint harmonic signals and minute voltage and current fluctuations in the power grid.

The GXSC ADC operates on a single 5V power supply and supports conversion of true bipolar input signals ranging from ±10V to ±5V. Through built-in calibration algorithms, the product comprehensively 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 Product Advantages

The product’s size, pinout, functionality, and timing support pin-to-pin replacement of the AD7656.

Single 5V power supply, compatible with ±15V power pins, facilitating the use of higher signal-to-noise ratios and higher linearity.

Lower bipolar zero-level error and lower positive and negative full-scale errors.

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)

+0.5 LSB (typical)

DNL: Operating Power Consumption:

110 mW (internal reference)

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

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, enabling direct acquisition of analog signals. The GXSC ADC integrates a flexibly configurable, high-precision reference voltage generator and buffer.