GXSC GX1248 заменяет ADS1248 в системах измерения температуры с термопарой

In the application process of flow instrumentation, fluid temperature is one of the important parameters to be measured and controlled. In temperature measurement, thermocouple is a widely used sensor, thermocouple has the advantages of good linearity, thermal electric potential, high sensitivity, stability and uniformity, strong oxidation resistance, wide temperature range, high temperature measurement accuracy and low price.

This paper focuses on the introduction of a GX1248 for thermocouple temperature measurement system, the choice of the GX1248 to meet the performance of the case, can reduce the number of devices to simplify the circuit design, the GX1248 data rate of up to 2ksps, the power consumption of only 2.56mw. can be a complete replacement for the ADS1248, to help reduce the project design costs.

The GX1248 includes many integrated features with low noise, programmable gain amplifiers, digital filters with single cycle stabilization and an internal oscillator that provides a built-in low-drift voltage reference and two matched programmable excitation current sources (IDACs). The input multiplexer supports four differential inputs. In addition, the multiplexer integrates sensor loss detection, thermocouple voltage biasing, system monitoring, and general-purpose digital V/os. The PGAs offer selectable gains up to 128 V/V.

These features provide a complete front-end solution for temperature sensor measurement applications including thermocouples, thermistors, and RTDs, as well as other small-signal measurement applications including resistance bridge sensors. Product Features:

- Up to 8/4 single-ended/differential channels

- PGA low noise 1~128V/V

- Internal reference: 8ppm/c and 0.05% accuracy

- Simultaneous 50Hz and 60Hz rejection at 5/10/20SPS data rates

- Analog supplies: Unipolar (2.7V to 5.25V) and Bipolar (±2.5V) operation

- Digital supply: 2.7V to 5.25V