Multi-function circuit with multi-function pin and method thereof

Abstract

A multi-function circuit uses a single multi-function pin to perform both light emitting diode (LED) driving and temperature sensing functions through time-division multiplexing. The multi-function circuit includes an LED driving circuit that provides a drive current to an LED during a first time period when the multi-function pin is configured as an output, and a temperature sensing circuit that generates a temperature-dependent voltage during a second time period when the multi-function pin is configured as an input. A voltage clamp circuit limits the maximum voltage at the multi-function pin to protect circuit components during transitions between operating modes. A sample and hold circuit samples and holds the temperature-dependent voltage as a holding voltage, making this information continuously available when the multi-function pin is being used to drive the LED.

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