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Ultra-Small Integrated AFE for Wearable, Optical Heart-Rate Monitoring and Biosensing


Package | PIN: YZP | 15
Temp: S (-20 to 70)
Carrier: Cut Tape
Qty Price
1-9 $5.05
10-24 $4.55
25-99 $4.25
100-249 $3.81
250-499 $3.55
500-749 $3.09
750-999 $2.68
1000+ $2.62


  • Transmitter:
    • Supports Common Anode LED Configuration
    • Dynamic Range: 100 dB
    • 6-Bit Programmable LED Current to 50 mA (Extendable to 100 mA)
    • Programmable LED On-Time
    • Simultaneous Support of 3 LEDs for Optimized SPO2, HRM, or Multi-Wavelength HRM
  • 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
    • Programmable Transimpedance Gain:
      10 kΩ to 2 MΩ
    • Dynamic Range: 100 dB
    • Average Current Less Than 200 µA for PPG Signal Acquisition
  • Pulse Frequency: 10 SPS to 1000 SPS
  • Flexible Pulse Sequencing and Timing Control
  • Flexible Clock Options:
    • External Clocking:
      4-MHz to 60-MHz Input Clock
    • Internal Clocking: 4-MHz Oscillator
  • I2C Interface
  • Operating Temperature Range: –20°C to 70°C
  • 2.6-mm × 1.6-mm DSBGA Package, 0.5-mm Pitch
  • Supplies: Rx: 2 V to 3.6 V, Tx: 3 V to 5.25 V,
    IO: 1.8 V to 3.6 V

Texas Instruments  AFE4404YZPT

The AFE4404 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 transimpedance amplifier (TIA) and 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. The device has a high dynamic range transmit and receive circuitry that helps with the sensing of very small signal levels.