GXSC ADC Replaces AD7609 in Smart Substations

The main equipment in smart substations includes smart transformers, smart high-voltage switchgear, and electronic current transformers. Smart transformers are connected to the control system via communication fiber optics, enabling real-time monitoring of transformer status parameters and operational data. They serve as the core hub for power grid dispatch, power transmission, and fault protection.

During the operation of a smart substation, multidimensional electrical parameters—such as three-phase voltage, three-phase current, zero-sequence voltage, and zero-sequence current—change simultaneously. Operating conditions are characterized by complex transient fault waveforms, dense harmonic interference, harsh electromagnetic environments, and high requirements for signal phase accuracy, necessitating a high-precision analog-to-digital converter (ADC) capable of synchronously sampling multiple electrical signals. This solution utilizes the GXSC eight-channel, 18-bit, 200 kSPS ADC.

The GXSC ADC is a low-power successive approximation ADC that supports synchronous sampling of eight true differential inputs. Each channel of this ADC achieves a conversion rate of up to 200 kSPS. Powered by a single 5V supply, the chip supports conversion of true bipolar differential input signals ranging from ±20V to ±10V. To simplify PCB design for data acquisition systems, the chip integrates a flexibly configurable, high-precision reference voltage generator and buffers. It features built-in input buffers with 1 MΩ input impedance and an anti-aliasing filter, facilitating direct analog signal acquisition.

GXSC ADC Product Advantages:

Product size, pinout, functionality, and timing are compatible with the reference product, supporting pin-to-pin replacement of the AD7609

Single 5V power supply, true bipolar differential analog input

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

Higher channel isolation

ENOB: 14.9 bits (typical)

SNR: 91.8 dB (typical)

SINAD: 91.5 dB (typical)

SFDR: -110 dB (typical)

INL: ±2.5 LSB (typical)

DNL: ±0.75 LSB (typical)

Operating Power Consumption: 120 mW (internal reference)

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

Available in a 64-pin LQFP package

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. It also integrates a flexibly configurable, high-precision reference voltage generator and buffer.