AFE4410YZR

The AFE4410YZR stands out as a versatile and sophisticated analog front-end solution tailor-made for optical biosensing applications, predominantly heart rate monitoring (HRM). Its capabilities include the support for up to four switching LEDs and three photodiodes, offering immense flexibility in sensor configurations. The device's efficient signal processing chain involves a transimpedance amplifier (TIA) for converting photodiode output into voltage, followed by an analog-to-digital converter (ADC) for digitization and storage in a 128-sample FIFO block. This FIFO block can be accessed through either I2C or SPI interfaces, ensuring seamless integration with various system architectures. Additionally, the AFE boasts an integrated LED driver with precise 8-bit current control, guaranteeing optimal performance in illumination for accurate biosensing. Its high dynamic range transmit-and-receive circuitry, with a dynamic range of up to 100 dB, enables precise and reliable heart rate measurements. Moreover, the device operates in an ultra-low power mode, activated through the ENABLE_ULP register bit, ensuring exceptional energy efficiency for prolonged battery life in portable applications

Key Features

• Accurate, Continuous Heart-Rate Monitoring:
  • Up to 100-dB Dynamic Range for Accurate Heart-Rate Detection
  • Low Current for Continuous Operation on a Wearable Device With a Typical Value:
    • 30 µA for an LED, 25 µA for the Receiver
• Transmitter:
  • 4 LEDs in Common Anode Configurations
  • 8-Bit Programmable LED Current to 200 mA
  • Mode to Fire Two LEDs in Parallel
  • Programmable LED On-Time
  • Simultaneous Support of 3 LEDs for Optimized SpO₂, HRM, or Multiwavelength HRM
  • Average Current of 30 µA Adequate for a Typical Heart-Rate Monitoring Scenario:
    • 20-mA Setting, 60-µs Pulse Duration,
      25-Hz Sampling Rate
• Receiver:
  • Supports 3 Time-Multiplexed PD Inputs
  • 24-Bit Representation of Current Input From PD in Two’s-Complement Format
  • Individual DC Offset Subtraction DAC
    (Up to ±127-µA Range) at TIA Input for Each LED, Ambient
  • Digital Ambient Subtraction at ADC Output
  • Transimpedance Gain: 10 kΩ to 2 MΩ
  • Noise Filtering With Programmable Bandwidth
  • Receiver Operates at Approximately 1-µA/Hz Sampling Rate (Example, 25 µA at 25 Hz)
  • Hardware Power-Down Mode: Approximately 0-µA Current
• Flexible Pulse Sequencing and Timing Control
• Clocking Via External Clock or Internal Oscillator
• FIFO With 128-Sample Depth:
  • Programmable Partitioning Across Phases
• Pin-Selectable I²C, SPI Interface
• Operating Temperature Range: –20°C to +70°C
• 2.6-mm × 2.1-mm, 0.4-mm Pitch DSBGA Package
• Supplies:
  • Tx: 3 V to 5.25 V
  • Rx: 1.8 V to 1.9 V (LDO Bypass),
    2.0 V to 3.6 V (LDO Enabled)
  • IO: 1.7 V to Rx_SUP