Texas Instruments OPA333AIDBVR | Demoboard TIDA-010043

Description

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.

Features

• Higher efficiency by providing headroom control tooptimally 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 currents (from 100 mA to 1.5 A)
• Compatible with AFE44xx series EVMs (tested with AFE4403 EVM) for driving LEDs
• Tested with MSP430G2553 LaunchPad™ and twoon-board LEDs (green and red)

Typical applications

• Temperature Measurements
• Medical Instrumentation
• Handheld Test Equipment

More information

• Datasheet
• IC product information