Ultra-Small Integrated Analog Front End (AFE) for Heart-Rate Monitors and Low-Cost Pulse Oximeters - AFE4403

AFE4403 (ACTIVE)

Ultra-Small Integrated Analog Front End (AFE) for Heart-Rate Monitors and Low-Cost Pulse Oximeters

 

Description

The AFE4403 is a fully-integrated analog front-end (AFE) ideally suited for pulse oximeter applications. The device consists of a low-noise receiver channel with an integrated analog-to-digital converter (ADC), an LED transmit section, and diagnostics for sensor and LED fault detection. The device is a very configurable timing controller. This flexibility enables the user to have complete control of the device timing characteristics. To ease clocking requirements and provide a low-jitter clock to the AFE4403, an oscillator is also integrated that functions from an external crystal. The device communicates to an external microcontroller or host processor using an SPI™ interface.

The device is a complete AFE solution packaged in a single, compact DSBGA-36 (3.07 mm × 3.07 mm × 0.5 mm) and is specified over the operating temperature range of –20°C to 70°C.

Features

  • Fully-Integrated AFE for Pulse Oximeter and Heart Rate Monitoring Applications:
  • Transmit:
    • Integrated Dual LED Driver
      (H-Bridge or Common Anode)
    • Option for a Third LED Support for Optimized SPO2, HRM, or Multi-Wavelength HRM
    • Up to 110-dB Dynamic Range
    • LED Current:
      • Programmable to 100 mA with 8-Bit Current Resolution
    • 30 µA + Average LED Current
    • Programmable LED On-Time
    • Independent LED2 and LED1 Current Reference
  • Receive Channel with High Dynamic Range:
    • 22-Bit Output in Twos Complement Format
    • Up to 105-dB Dynamic Range
    • Low Power: < 650 µA
    • Dynamic Power-Down Mode to Reduce Current to 300 µA
    • Adaptable to a Very Wide Range of Signal Amplitudes:
      • Total Programmable Gain: 10 kΩ to 4 MΩ
    • Integrated Digital Ambient Estimation and Subtraction
  • Flexible Clocking by External Clock or Crystal:
    • Pulse Frequency: 62.5 SPS to 2000 SPS
    • Flexible Pulse sequencing and Timing Control
    • Input Clock Range: 4 MHz (Min) to 60 MHz (Max)
  • Integrated Fault Diagnostics:
    • Photodiode and LED Open and
      Short Detection
  • Supplies:
    • Rx = 2.0 V to 3.6 V
    • Tx = 3.0 V to 5.25 V
  • Package: Compact DSBGA-36
    (3.07 mm × 3.07 mm × 0.5 mm)
  • Specified Temperature Range: –20°C to 70°C

View more

Parametrics Compare all products in Photodiode Sensing

 
# Input Channels
Resolution (Bits)
Interface
Sample Rate (max) (SPS)
Number of LEDs
Package Group
Rating
Operating Temperature Range (C)
Package Size: mm2:W x L (PKG)
Features
AFE4403 AFE4404 AFE4405 AFE4410 AFE4490 AFE4900
1    1    2    3    1    3   
22    24    24    24    22    24   
SPI    I2C    I2C
SPI   
SPI
I2C   
Serial SPI    SPI
I2C   
2KSPS    1KSPS    1KSPS    1KSPS    5KSPS    1KSPS   
3    3    3    4    2    4   
DSBGA    DSBGA        VQFN     
Catalog    Catalog    Catalog    Catalog    Catalog    Catalog   
-20 to 70    -20 to 70    -20 to 70    -20 to 70    -40 to 85    -20 to 70   
See datasheet (DSBGA)    See datasheet (DSBGA)        40VQFN: 36 mm2: 6 x 6(VQFN)     
Optical biosensing    Optical biosensing    Optical biosensing    Optical biosensing    Optical biosensing    Optical biosensing