The ADS1225 and ADS1226 are 24-bit delta-sigma analog-to-digital (A/D) converters. They offer excellent performance, ease-of-use, and low power in a small 4mm × 4mm QFN package and are well-suited for demanding high-resolution measurements, especially in portable and other space-saving and power-constrained applications.

The ADS1225 and ADS1226 convert on command using a dedicated START pin. Simply pulse this pin to initiate a conversion. Data is read in a single cycle for retrieval over a 2-wire serial interface that easily connects to popular microcontrollers like the MSP430. After the conversion completes, the ADS1225 and ADS1226 automatically shuts down all circuitry.

Internal features include a two-channel multiplexer (ADS1226), selectable input buffer, temperature sensor, and oscillator. The full-scale range is defined by the external voltage reference with support provided for up to a 5V differential input signal. Two operating modes allow for speed (100SPS data rate, 15µVRMS noise) or resolution (4µVRMS noise, 16SPS data rate).

The ADS1225/6 supports 2.7 to 5.5V analog and digital supplies. Power consumption is 1mW while converting with 3V supplies. The ADS1225 and ADS1226 are fully specified over an extended industrial temperature range of -40°C to +105°C.

• 100SPS Data Rate (High-Speed Mode)
• Single-Cycle Settling
• Easy Conversion Control with START Pin
• Automatic Shutdown
• Low Noise: 4µVRMS Noise (High-Resolution Mode)
• Input Multiplexer with Two Differential Channels (ADS1226)
• Voltage Reference Supports Ratiometric Measurements
• Self-Calibrating
• Simple Read-Only 2-Wire Serial Interface
• Internal High-Impedance Input Buffer
• Internal Temperature Sensor
• Internal Oscillator
• Low-Power: 1mW While Operating, < 1µA During Shutdown
• Analog and Digital Supplies: 2.7V to 5.5V
• APPLICATIONS
  • Hand-Held Instrumentation
  • Portable Medical Equipment
  • Industrial Process Control