ANALOG DEVICES AD7781BRZ Analogue to Digital Converter, 20 bit, 16.7 SPS, Single Ended, 2 Wire, Serial, Single, 2.7 V

AD7781BRZ is a 20-bit, pin-programmable, low power sigma-delta ADC. It is a complete, low power front-end solution for bridge sensor products, including weigh scales, strain gages, and pressure sensors. It contains a precision, low power, 20-bit sigma-delta (?-?) ADC, an on-chip, low noise programmable gain amplifier (PGA), and an on-chip oscillator. Consuming only 330?A, the AD7781 is particularly suitable for portable or battery-operated products where very low power is required. It also has a power-down mode that allows the user to switch off the power to the bridge sensor and power down the AD7781 when not converting, thus increasing the battery life of the product. For ease of use, all the features of the device are controlled by dedicated pins. Each time that a data read occurs, eight status bits are appended to the 20-bit conversion. It is used in applications such as weigh scales, pressure measurement, industrial process control, portable instrumentation.

• Pin-programmable in-amp gain, pin-programmable power-down and reset
• Status function, internal clock oscillator, internal bridge power-down switch
• Simultaneous 50Hz/60Hz rejection, power supply range from 2.7V to 5.25V
• 2-wire serial interface (read-only device), SPI compatible, schmitt trigger on SCLK
• Integral nonlinearity is ±6ppm FSR typical at (AVDD = 2.7V to 5.25V, VREF = AVDD)
• Gain drift vs. temperature is ±2ppm/°C typical at (AVDD = 2.7V to 5.25V, VREF = AVDD)
• Common-mode rejection ratio is 110dB typical at (AVDD = 2.7V to 5.25V, VREF = AVDD)
• Offset error is ±6?V typical at (gain = 128 with FILTER = 1, AVDD = 2.7V to 5.25V, VREF = AVDD)
• Power supply rejection ratio is 100dB typical at (Gain = 128, FILTER = 1, AIN = 7.81mV)
• Operating temperature range from -40°C to +105°C, 14-lead SOIC-N package

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party