Features of AFE4403

Fully integrated AFE for pulse oximetry and heart rate monitoring applications:

send:

Integrated dual LED drivers

(H bridge or common anode)

Optional third LED supports optimized SPO2, HRM or multi-wavelength HRM

Up to 110dB 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 References

Receive channel with high dynamic range:

22-bit output in twos complement format

Up to 105dB dynamic range

Low power consumption: <650 μA

Dynamic Power-Down Mode Reduces Current to 300 μA

To accommodate a wide range of signal amplitudes:

Programmable Overall Gain: 10kΩ to 4MΩ

Integrated digital environment estimation and subtraction

Flexible timing via 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 Troubleshooting:

Photodiode and LED open circuit and

Short circuit detection

Consumables:

Rx = 2.0 V to 3.6 V

Tx = 3.0 V to 5.25 V

Packaging: Compact DSBGA-36

(3.07mm x 3.07mm x 0.5mm)

Specified temperature range: –20°C to 70°C

Description of AFE4403

The AFE4403 is a fully integrated analog front end (AFE) ideal for pulse oximetry 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. This device is a very configurable timing controller. This flexibility gives the user complete control over the timing characteristics of the device. To ease the clocking requirements and provide a low-jitter clock to the AFE4403, an oscillator is also integrated that operates from an external crystal. The device uses the SPI™ interface to communicate with an external microcontroller or host processor.

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