Efficient, high-current, linear LED driver reference design for SpO2 and other medical applications
This reference design provides a protected, efficient (headroom-controlled), high-current (up to 1.5 A), linear (accurate and fast) light-emitting diode (LED) driver reference design to enable peripheral capillary oxygen saturation (SpO2) and other medical applications. A typical SpO2 application drives current through LEDs. Most of these drivers are integrated with analog front-end devices and work at the typical value of 100 mA. A higher current drive is necessitated to cover wide range of human and veterinary physiology. This design enables self-calibration and uses a look-up table for headroom control to optimally drive LEDs resulting in minimum power dissipation across the control element. The design operated from an input voltage range of 1.8 V to 4.2V and enables LED currents up to 1.5 A.
- Higher efficiency by providing headroom control to optimally drive LED:
- - Built-in self-calibration and look-up table for headroom control
- Dynamic adjustment of the LED supply voltage, to achieve optimal efficiency at the programmed current levels
- Diagnostics (LED open, LED short, LED disconnect) and protection mechanism for fault by disconnecting the supply using e-fuse
- Wide operating input range from 1.8 V to 5.5 V to support all battery type inputs
- Programmable range selection for LED current (from 100 mA to 1.5 A)
- Compatible with AFE44xx series EVMs (tested with AFE4403 EVM) for driving LEDs
- Tested with MSP430G2553 LaunchPad™ and two on-board LEDs (green and red)
A fully assembled board has been developed for testing and performance validation only, and is not available for sale.
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Reference design overview and verified performance test data
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Design file that contains information on physical board layer of design PCB
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Includes TI products in the design and potential alternatives.
CSD13202Q2 — 12-V, N channel NexFET™ power MOSFET, single SON 2 mm x 2 mm, 9.3 mOhmData sheet: PDF | HTML
|*||Design guide||Efficient, high current, linear LED driver reference design for SpO2||Mar. 08, 2019|
|More literature||TIDA-010043 Firmware||Mar. 08, 2019|
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