AFE4410 Ultra-Small Integrated AFE With FIFO for Wearable Optical Heart-Rate Monitoring and Biosensing |


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

Ultra-Small Integrated AFE With FIFO for Wearable Optical Heart-Rate Monitoring and Biosensing - AFE4410

More Information

Full data sheet and other design resources are available under NDA. Request now


The AFE4410 is an analog front-end for optical biosensing applications, such as heart-rate monitoring (HRM). The device supports up to four switching light-emitting diodes (LEDs) and up to three photodiodes (PDs). 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 is stored in a 128-sample first in, first-out block (FIFO) with programmable depth. The FIFO can be read out using either an I2C interface or a serial peripheral interface (SPI). The AFE also has a fully integrated LED driver with 8-bit current control. The device has high dynamic range transmit-and-receive circuitry offering a dynamic range of up to 100 dB that enables accurate heart-rate sensing. The AFE achieves extremely low current levels by operating an ultralow power (ULP) mode set by using the ENABLE_ULP register bit.


  • 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

All trademarks are the property of their respective owners.

View more

Parametrics Compare all products in Biosensing AFEs

# Input Channels
Resolution (Bits)
Number of LEDs
Operating Temperature Range (C)
Package Group
Package Size: mm2:W x L (PKG)
Approx. Price (US$)
AFE4410 AFE4403 AFE4404 AFE4405 AFE4420 AFE4490 AFE4900
3     1     1     2     4     1     3    
24     22     24     24     24     22     24    
SPI     I2C     I2C
I2C     Serial SPI     SPI
4     3     3     3       2     4    
Optical biosensing     Optical biosensing     Optical biosensing     Optical biosensing     Optical Biosensing     Optical biosensing     Optical biosensing    
-20 to 70     -20 to 70     -20 to 70     -20 to 70     -40 to 85     -40 to 85     -20 to 70    
  DSBGA     DSBGA         VQFN      
  See datasheet (DSBGA)     See datasheet (DSBGA)         40VQFN: 36 mm2: 6 x 6(VQFN)      
2.65 | 1ku     3.25 | 1ku     2.28 | 1ku     2.50 | 1ku     4.10 | 1ku     7.95 | 1ku     2.75 | 1ku