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    Maxim Integrated > Development Platforms and Kits > Reference Designs >
    • Ratiometric measurement or measurement compared to a precision voltage reference
    • User-programmable offset and gain calibration for sensor (load cell)
    • User-programmable offset and gain calibration for DAC
    • User-programmable voltage output range mapping


    • 24-bit resolution, 64ksps
    • 6nV/√Hz Integrated programmable-gain amplifier (PGA) with gains up to 128


    • 16-bit resolution with no missing codes
    • High accuracy: INL ±2 LSB (max)
    Weigh scales perform the critical function of mass measurement for a wide variety of industrial applications. From ultra-small reactant amounts to large cargo containers, weighing provides key information in an array of processes from chemical reactions to commodity management. The critical component of any modern weigh scale is the analog-to-digital converter.

    The MAXREFDES75# brings a full 24-bit ADC into a high-performance system performing small-signal (down to ±25mV full scale) 24-bit measurements, while generating the high-voltage sensor supply, and producing a 0 to 10V output proportional to the input signal.

    The signal chain begins with the sensor signal feeding directly into the MAX11270. No external op amp is necessary because the PGA is integrated in the MAX11270. Following isolation via the MAX14850, the MAXQ622 reads the input signal, applies zero-offset and weight-factor, and presents the resulting weight. The MAXQ622 calculates a DAC value, based on DAC calibration and output range mapping and writes this to the DAC.