AFE4490RHAT

Analog Front End (AFE) Overview

The AFE4490RHAT is an integrated analog front-end (AFE) designed for pulse oximeter applications, manufactured by Texas Instruments. It features a low-noise receiver channel with a 22-bit ADC, an LED transmission unit, and diagnostic functions for sensor and LED fault detection. The device includes a configurable timing controller and an oscillator powered by an external crystal to provide a low-jitter clock. Communication with external microcontrollers occurs via an SPI interface. It operates within a supply voltage range of 2 V to 3.6 V and is housed in a compact VQFN-40 package.

Analog Front End (AFE) Feature Summary

• Integrated 22-bit ADC with low-noise receiver channel
• Configurable timing controller with external crystal oscillator
• SPI interface for host communication
• Diagnostic capabilities for LED and sensor faults

Analog Front End (AFE) Applications

• Pulse oximeters
• Biometric authentication systems using PPG signals

Analog Front End (AFE) Procurement Notes

Verify the specific suffix RHAT corresponds to the tape-and-reel packaging configuration as indicated by distributor listings. Confirm RoHS compliance status through official documentation before procurement. Ensure the order matches the exact part number to avoid compatibility issues with evaluation boards or reference designs.

Analog Front End (AFE) Selection Notes

Select this component for applications requiring high-resolution optical biosensing with integrated LED driving and reception. The 22-bit resolution and low input noise are critical for accurate SpO2 measurements. Consider the VQFN-40 package size constraints and the requirement for an external crystal for clock generation when designing the PCB layout.

Analog Front End (AFE) Part Context

The AFE4490RHAT belongs to the AFE4490 series from Texas Instruments. It is specifically engineered for medical-grade pulse oximetry, offering a complete solution in a single compact package. The RHAT suffix typically denotes the reel packaging variant used for automated assembly processes.

Analog Front End (AFE) Replacement Considerations

The AFE4400 is a related device but lacks independent gain settings for LED1 and LED2 channels found in the AFE4490. Direct substitution requires verifying if the application utilizes separate gain configurations for different wavelengths.