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Texas Instruments AFE4404 Ultra-Small Integrated AFE

Texas Instruments AFE4404 Ultra-Small Integrated AFE is an analog front-end (AFE) for optical bio-sensing applications, such as heart-rate monitoring (HRM) and saturation of peripheral capillary oxygen (SpO2). The device supports three switching light-emitting diodes (LEDs) and a single photodiode. The current from the photodiode is converted into voltage by the trans-impedance amplifier (TIA). It is then digitized using an analog-to-digital converter (ADC). The ADC code can be read out using an I2C interface. The AFE also has a fully integrated LED driver with a 6-bit current control. Texas Instruments AFE4404 Ultra-Small Integrated AFE has a high dynamic range transmit and receive circuitry that helps with the sensing of very small signal levels.

Features

  • Receiver
    • 24-bit representation of the current input from a photodiode in twos complement format
    • Individual DC offset subtraction DAC at TIA input for each LED and ambient phase
    • Digital ambient subtraction at ADC output
    • 10kΩ to 2MΩ programmable trans-impedance gain
    • Dynamic power-saving mode to reduce current to less than 200µA
    • 10SPS to 1000SPS pulse frequency
    • Flexible pulse sequencing and timing control
    • Flexible Clock Options
      • 4MHz to 60MHz input clock external clocking
      • 4MHz oscillator internal clocking
    • I2C interface
    • -20°C to +70°C operating temperature range
    • 2.6mm × 1.6mm DSBGA package, 0.5mm pitch
    • Supplies
      • Rx: 2V to 3.6V
      • Tx: 3V to 5.25V
      • IO: 1.8V to 3.6V
  • Transmitter
    • Supports common anode LED configuration
    • 100dB dynamic range
    • 6-bit programmable LED current to 50mA (extendable to 100mA)
    • Programmable LED on-time
    • Simultaneous support of 3 LEDs for optimized SPO2, HRM, or multi-wavelength HRM

Applications

  • Optical Heart-Rate Monitoring (HRM)
  • Heart-Rate Variability (HRV)
  • Pulse oximetry (SpO2 measurement)
  • VO2 max
  • Calorie expenditure

Additional Resources

Simplified Block Diagram

Texas Instruments AFE4404 Ultra-Small Integrated AFE

Related Development Tool

Texas Instruments Heart Rate Monitoring & Pulse Oximetry Eval Kit

Contains everything you need to evaluate TI AFE4404 devices.

Learn Moreà propos de Texas Instruments Heart Rate Monitoring & Pulse Oximetry Eval Kit View Productslié à Texas Instruments Heart Rate Monitoring & Pulse Oximetry Eval Kit
Publié le: 2015-07-10 | Mis à jour le: 2023-11-01