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Description

The ADS1258 is a 16-channel (multiplexed), low-noise, 24-bit, delta-sigma analog-to-digital converter (ADC) that provides single-cycle settled data at channel scan rates from 1.8k to 23.7k samples per second (SPS). A flexible input multiplexer accepts combinations of eight differential or 16 single-ended inputs with a full-scale differential range of 5V or true bipolar range of ±2.5V when operating with a 5V reference. The fourth-order delta-sigma modulator is followed by a fifth-order sinc digital filter optimized for low-noise performance.

The differential output of the multiplexer is accessible to allow signal conditioning prior to the input of the ADC. Internal system monitor registers provide supply voltage, temperature, reference voltage, gain, and offset data.

An onboard PLL generates the system clock from a 32.768kHz crystal, or can be overridden by an external clock source. A buffered system clock output (15.7MHz) is provided to drive a microcontroller or additional converters.

Serial digital communication is handled via an SPI(tm)-compatible interface. A simple command word structure controls channel configuration, data rates, digital I/O, monitor functions, etc.

Programmable sensor bias current sources can be used to bias sensors or verify sensor integrity.

The ADS1258 operates from a unipolar +5V or bipolar ±2.5V analog supply and a digital supply compatible with interfaces ranging from 2.7V to 5.25V. The ADS1258 is available in a QFN-48 package.

Key Features

• 24 Bits, No Missing Codes
• Fixed-Channel or Automatic Channel Scan
• Fixed-Channel Data Rate: 125kSPS
• Auto-Scan Data Rate: 23.7kSPS
• Single-Conversion Settled Data
• 16 Single-Ended or 8 Differential Inputs
• Unipolar (+5V) or Bipolar (±2.5V) Operation
• Low Noise: 2.8µVRMS at 1.8kSPS
• 0.0003% Integral Nonlinearity
• DC Stability (typical):
  0.02µV/°C Offset Drift, 0.4ppm/°C Gain Drift
• Open-Sensor Detection
• Conversion Control (Pin and Commands
• Multiplexer Output for External Signal Conditioning
• On-Chip Temperature, Reference, Offset, Gain, and Supply Voltage Readback
• 42mW Power Dissipation
• Standby, Sleep, and Power-Down Modes
• 8 General-Purpose Inputs/Outputs (GPIO)
• 32.768kHz Crystal Oscillator or External Clock

Information: SPI is a trademark of Motorola, Inc.
All trademarks are the property of their respective owners.

Related Links

Texas Instrument Product Page

Data Sheet (PDF 893 kB)