ADS1148 - 16-Bit 2kSPS 8-Ch ADC With PGA, Reference, and IDAC for Precision Sensor Measurement

The ADS1146, ADS1147, and ADS1148 devices are precision, 16-bit analog-to-digital converters (ADCs) that include many integrated features to reduce system cost and component count for sensor measurement applications. The devices feature a low-noise, programmable gain amplifier (PGA), a precision delta-sigma (ΔΣ) ADC with a single-cycle settling digital filter, and an internal oscillator. The ADS1147 and ADS1148 devices also provide a built-in, low-drift voltage reference, and two matched programmable excitation current sources (IDACs).

An input multiplexer supports four differential inputs for the ADS1148, two for the ADS1147, and one for the ADS1146. In addition, the multiplexer integrates sensor burn-out detection, voltage bias for thermocouples, system monitoring, and general purpose digital I/Os (ADS1147 and ADS1148). The PGA provides selectable gains up to 128 V/V. These features provide a complete front-end solution for temperature sensor measurement applications including thermocouples, thermistors, and resistance temperature detectors (RTDs) and other small signal measurements including resistive bridge sensors. The digital filter settles in a single cycle to support fast channel cycling when using the input multiplexer and provides data rates up to 2 kSPS. For data rates of 20 SPS or less, both 50-Hz and 60-Hz interference are rejected by the filter.

• Programmable Data Rates Up to 2 kSPS
• Single-Cycle Settling for All Data Rates
• Simultaneous 50-Hz and 60-Hz Rejection at
  20 SPS
• Analog Multiplexer With 8 (ADS1148) and
  4 (ADS1147) Independently Selectable Inputs
• Programmable Gain: 1 V/V to 128 V/V
• Dual-Matched Programmable Excitation Current Sources
• Low-Drift Internal 2.048-V Reference
• Sensor Burnout Detection
• 4 or 8 General-Purpose I/Os (ADS1147 and ADS1148)
• Internal Temperature Sensor
• Power Supply and V_REF Monitoring (ADS1147 and ADS1148)
• Self and System Calibration
• SPI™-Compatible Serial Interface
• Analog Supply: Unipolar (2.7 V to 5.25 V) or Bipolar (±2.5 V)
• Digital Supply: 2.7 V to 5.25 V