An 18-channel wireless autonomous datalogger ASIC for strain gauge sensors
This single-chip 18-channel strain-gauge datalogger combines a 10μstrain-accuracy sensor interface with digital offset-compensation, a wireless 132kHz/66kHz transceiver and a 23.4kgates digital unit with programmable data processing. The sensor interface includes a current reference, an 8-bit DAC, together with a digital interface to achieve multigauge nulling, an offset-compensated SC-instrumentation amplifier, a SC S/H and a 9-bit successive approximation ADC. The datalogger's maximum power consumption, including an external 2-Mbit RAM, is 136μW/channel at 3.1V.
Features:
- 40uA ULP current consumption per strain gauge channel
- Dynamic accuracy better than 10ustrain
- Standard deviation of error is 6.5ustrain
- 18 channel readout, bandwidth of 50Hz
- Input referred voltage of 8.84uV
- 0.7u CMOS technology