SBAS889A January 2020 – April 2021 ADS131M03
PRODUCTION DATA
The ADS131M03 is a low-power, three-channel, simultaneously sampling, 24-bit, delta-sigma (ΔΣ) analog-to-digital converter (ADC) with a low-drift internal reference voltage. The dynamic range, size, feature set, and power consumption are optimized for cost-sensitive applications requiring simultaneous sampling.
The ADS131M03 requires both analog and digital supplies. The analog power supply (AVDD – AGND) can operate between 2.7 V and 3.6 V. An integrated negative charge pump allows absolute input voltages as low as 1.3 V below AGND, which enables measurements of input signals varying around ground with a single-ended power supply. The digital power supply (DVDD – DGND) accepts both 1.8-V and 3.3-V supplies. The device features a programmable gain amplifier (PGA) with gains up to 128. An integrated input precharge buffer enabled at gains greater than 4 ensures high input impedance at high PGA gain settings. The ADC receives its reference voltage from an integrated 1.2-V reference. The device allows differential input voltages as large as the reference. Three power-scaling modes allow designers to trade power consumption for ADC dynamic range.
Each channel on the ADS131M03 contains a digital decimation filter that demodulates the output of the ΔΣ modulators. The filter enables data rates as high as 32 kSPS per channel in high-resolution mode. The relative phase of the samples can be configured between channels, thus enabling an accurate compensation for the sensor phase response. Offset and gain calibration registers can be programmed to automatically adjust output samples for measured offset and gain errors. The Section 8.2 provides a detailed diagram of the ADS131M03.
The device communicates via a serial programming interface (SPI)-compatible interface. Several SPI commands and internal registers control the operation of the ADS131M03. Other devices can be added to the same SPI bus by adding discrete CS control lines. The SYNC/RESET pin can be used to synchronize conversions between multiple ADS131M03 devices as well as to maintain synchronization with external events.