AFE4405 Description
The AFE4405 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 up to two photodiodes. The current from the photodiode is converted into voltage by the transimpedance amplifier (TIA) and digitized using an analog-to-digital converter (ADC).
AFE4405 Key Features
- 1 Transmitter
- Supports mon Anode LED Configuration
- Dynamic Range: 100 dB
- 8-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
- Supports 2 Time-Multiplexed Photodiode Inputs
- 24-Bit Representation of the Current Input from the Photodiode in Twos plement Format
- Individual DC Offset Subtraction DAC (±15.75-µA Range) at TIA Input for Each LED, Ambient
AFE4405 Applications
- Optical Heart-Rate Monitoring (HRM) for Wearables, Hearables