AFE4404 Datasheet | Texas Instruments

Features - 1 Transmitter: - Supports mon Anode LED Configuration - Dynamic Range: 100 d B - 6-Bit Programmable LED Current to 50 m A (Extendable to 100 m A) - Programmable LED On-Time - Simultaneous Support of 3 LEDs for Optimized Sp O2, HRM, or Multi-Wavelength HRM - Receiver: - 24-Bit Representation of the Current Input from a Photodiode in Twos plement Format - Individual DC Offset Subtraction DAC at TIA Input for Each LED and Ambient Phase - Digital Ambient Subtraction at ADC Output - Programmable Transimpedance Gain: 10 kΩ to 2 MΩ - Dynamic Range: 100 d B - Average Current Less Than 200 μA for PPG Signal Acquisition - Pulse Frequency: 10 SPS to 1000 SPS - Flexible Pulse Sequencing and Timing Control - Flexible Clock Options: - External Clocking: 4-MHz to 60-MHz Input Clock - Internal Clocking: 4-MHz Oscillator - I2C Interface - Operating Temperature Range: - 20°C to 70°C - 2.6-mm × 1.6-mm DSBGA Package, 0.5-mm Pitch - Supplies: Rx: 2 V to 3.6 V, Tx: 3 V to 5.25 V, IO: 1.8 V to 3.6 V 2 Applications - Optical Heart-Rate Monitoring (HRM) - Heart-Rate Variability (HRV) - Pulse Oximetry (Sp O2 Measurement) - VO2 Max - Calorie Expenditure 3 Description The AFE4404 is an analog front-end (AFE) for optical bio-sensing applications, such as heart-rate monitoring (HRM) and saturation of peripheral capillary oxygen (Sp O2). The device supports three switching light-emitting diodes (LEDs) and a single photodiode. 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 can be read out using an I2C interface. The AFE also has a fullyintegrated LED driver with a 6-bit current control. The device has a high dynamic range transmit and receive circuitry that helps with the sensing of very small signal levels. Device Information(1) PART NUMBER PACKAGE DSBGA (15) BODY SIZE (NOM) 2.60 mm × 1.60 mm(2) (1) For all available packages, see the orderable addendum at the...