GXSC AFE Replaces AD4115 in Analog Input (AI) Modules

Analog input modules are products designed for analog signal acquisition from industrial field instruments and are widely used for collecting data from field instruments such as pressure, flow, level, temperature, concentration, and valve position sensors. When combined with AO modules, DI modules, DO modules, and Profinet network modules, they form a distributed slave system to enable signal acquisition and control output for instruments, meters, and equipment in industrial automation systems.

Industrial field environments are complex, characterized by strong electromagnetic interference, significant temperature fluctuations, and diverse signal types. For data acquisition, GXSC’s 24-bit, 125 kSPS, 8/16-channel, highly integrated AFE can be employed to perform the core tasks of analog signal acquisition, conditioning, and analog-to-digital conversion. Working in concert with sensors, MCUs (microcontroller units), isolation circuits, and communication interfaces to form a complete AI module acquisition chain, enabling precise acquisition and digital transmission of analog signals from industrial field environments.

The GXSC AFE is designed around a Σ-Δ ADC core. Its integrative acquisition characteristics provide better noise suppression capabilities compared to SAR-type ADCs, while also enabling power-line noise suppression. Additionally, the device employs a true differential input structure. In industrial environments, this differential input structure provides superior suppression of ground common-mode interference and other noise disturbances. The device’s front end integrates a high-voltage resistor network, supporting ±10V acquisition with a single 5V power supply and providing up to ±40V input protection. It also supports a greater number of channels (8 differential or 16 single-ended) and features open-circuit zeroing.

The application features of the GXSC AFE are as follows:

• Effective resolution: 17.9bits@62.5kSPS

• Total uncalibrated error: 0.07%

• Offset as low as: 0.5mV

• High AC PSRR: 50dB @ 50Hz–100kHz

• High integration: Integrated internal reference (temperature drift: 6ppm/°C (Typ.)), precision voltage divider resistors, and an integrated 2°C high-precision temperature sensor

• Supports simultaneous 50/60Hz suppression

• Supports SPI CRC check

• Open-circuit detection: Output returns to zero upon input open-circuit

• Higher ESD/temperature ratings: 2000V/1250V HBM/CDM

• Digital supply voltage: 2.7V–5.5V; Analog supply voltage: 4.5V–5.5V

• Package: 6.0mm × 6.0mm QFN (40-pin)

• Operating temperature range: –40°C to +125°C