TI unveils the first integrated analog front end for photometry applications

January 08, 2013 // Paul Buckley

Texas Instruments Incorporated has unveiled the industry’s first family of fully integrated analog front ends (AFEs) for photometry.

The AFE44xx family integrates all the front end components and associated timing control circuitry of a typical photometry solution. Applications include clinical and home health pulse oximeters, photometry-based blood glucose meters, and photoplethysmograph-based (PPG) heart rate monitors.

By incorporating fully programmable transmitter and receiver circuits into one device, the AFE44xx family reduces end equipment manufacturers’ design time, board space and need for in-house analog design expertise compared to discrete solutions. With less than 1-mA supply current, the AFE44xx family consumes less power than discrete solutions, which results in longer battery life. The AFE44xx family enables optimal measurement performance, even in ambient light settings.

With its high level of integration and low power, the AFE44xx family enables smaller, more portable traditional photometry solutions, as well as the new emerging market of wireless and smart connected pulse oximeter accessories. Available in the AFE44xx family are the AFE4490, targeted at clinical applications; and the AFE4400, targeted for home health applications.

The AFE44xx family’s receive path includes a programmable transimpedance amplifier (TIA), ambient cancellation circuitry and analog-to-digital converter (ADC).  The transmit path incorporates the LED driver and programmable 8-bit current source of up to 150 mA. With both transmit and receive paths integrated into a single device, less time and board space is required to design with the device.

The device family consumes less than 1 mA of power, to extend battery life and offers  open/short detection features make it easier for engineers to diagnose system errors during design.

The AFE44xx family provides a flexible integrated timing controller module that reduces the demands and overhead on system software.

Availability and Pricing

Both the AFE4490 and the AFE4400 are available now in a compact 6-mm x 6-mm, 40-pin QFN package.  The AFE4490 is priced at $7.95 and the AFE4400 is priced at $2.95 in quantities of 1,000.

Tools and support

Designers can immediately take advantage of the AFE4490 and AFE4400 evaluation modules (EVMs) which feature DB9 pulse oximeter sensor cable support, include two modes of operation for evaluation and live SPO2 / heart rate, and provide access to all the AFE44xx device registers via an easy-to-use graphical user interface (GUI).  

More information about the AFE44xx family and evaluation modules (EVMs) at www.ti.com/afe4400-pr and www.ti.com/afe4400evm-pr

Technical papers     

• AR RF/Microwave Instrumentation Field Analyzers
• 16-Bit, 100 kSPS Low Power Successive Approximation ADC System
• Replacing the Candle in the Candelabra
• Adaptive Cell Converter Topology Enables Constant Efficiency in PFC Applications

December 15, 2011 | Texas instruments | 222901974

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