GXSC Analog-to-Digital Converter Replaces AD7608 in Variable Frequency Drives

Variable frequency drives (VFDs) are power control devices primarily used to regulate the speed and torque of AC motors. They achieve precise motor control by altering the frequency and voltage of the motor‘s operating power supply, thereby enhancing energy efficiency and extending equipment lifespan. Inverter operation requires real-time synchronous acquisition of multiple analog signals, including key parameters such as three-phase input voltage/current, three-phase output voltage/current, motor speed feedback, and temperature. This necessitates a multi-channel synchronous sampling ADC featuring high precision, high sampling rate, and strong anti-interference capabilities. The GXSC eight-channel 18-bit 200kSPS synchronous sampling ADC is exceptionally well-suited for the complex electromagnetic environments and high-frequency signal acquisition demands of industrial settings.

The GXSC ADC integrates eight 18-bit fast, low-power successive approximation ADCs, supporting synchronous sampling across all channels. This ensures synchronized acquisition of multiple parameters and guarantees phase consistency between voltage/current signals and signals with different phase sequences. Each channel achieves a conversion rate of up to 200kSPS. Powered solely by a 5V supply, the chip supports true bipolar input signals ranging from ±10V to +5V. Through built-in calibration algorithms, the product not only matches the ADC performance of imported reference products but also achieves a low bipolar zero-level error of +4LSB and channel isolation below -100dB.

The GXSC ADC incorporates an input buffer with 1MΩ input impedance and an anti-aliasing filter for direct analog signal acquisition. It integrates a flexible, configurable high-precision reference voltage generator and buffer, simplifying PCB design for data acquisition systems. The chip supports parallel or serial modes, configurable via different hardware pin connections. This capability creates multiple connection options for interfacing the device with microprocessors or DSPs.

GXSC Domestic Analog-to-Digital Converter Product Advantages:

Pin-to-pin replacement for AD7608 with identical dimensions, pinout, functionality, and timing

Single 5V power supply

Lower bipolar offset error and lower positive/negative full-scale error

Higher channel isolation

ENOB: 14.6 bits (typical)

 SNR: 90.9dB (typical)

SINAD: 89dB (typical)

SFDR: -105dB (typical)

INL: +2.5LSB (typical)

DNL: ±0.75LSB (typical)

Operating Power Consumption: 120mW (internal reference)

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