Application of Highly Integrated AFE GX1120 Compatible with ADS1120 in Analog Input (AI) Modules

Analog input module is a product used for collecting analog signals (0-10v, 4-20mA) from industrial field instruments. It is widely used for collecting information from field instruments such as pressure, flow rate, liquid level, temperature, concentration, and valve position. Combined with AO module, DI module, DO module, and ProfiNet network module, a distributed slave station is formed to achieve signal acquisition and control output of instruments, meters, and equipment in industrial automation systems. The excellent electrical characteristics of the highly integrated AFE GX1120 make it an ideal choice for analog input modules.

The analog signal range in general industrial sites varies greatly, which requires AFE to have a wide input range (at least ± 20mV to ± 10V) and high resolution (≥ 16 bits). GX1120 AFE fully meets the requirements, can PIN TO PIN compatible with ADS1120, has high precision and wide dynamic range, strong anti-interference ability, and is adaptable to multiple sensors with flexibility.

The GX1120 has three differential or five single ended inputs, through a flexible input multiplexer (MUX), a low-noise, programmable gain amplifier, bias voltage for each channel, two programmable excitation current sources, a voltage reference, an oscillator, a low side switch, and a precision temperature sensor. GX1120 can convert at a data rate of up to 3710kSPS. At<20SPS, digital filters can provide noise suppression for industrial applications at 50Hz or 60Hz.

The GX1120 internal PGA provides a revenue of up to 128V/V. The PGA makes the GX1120 highly suitable for applications that measure signals from small sensors such as resistance temperature detectors (RTDs), thermocouples, thermistors, and resistance bridge sensors. And it is packaged in lead-free QFN-16 or TSSOP-16, suitable for a temperature range of -40 ° C to+125 ° C. Its characteristics are as follows

Low current consumption: as low as 75 μ A (typical value) in duty cycle mode

Wide power range: 2.7V to 5.25V

• Programmable gain: 1V/V to 128V/V

• Programmable data rate: up to 3.7kSPS

50Hz or 60Hz suppression with a single cycle set digital filter at ≤ 20SPS

Three differential or five single ended inputs

Internal bias voltage generator

Dual matching programmable current source: 10 μ A to 1.5mA

Internal 2.048VR frequency: 8ppm/° C (typical value) drift