Design of Automotive Ambient Lighting with Color Stability under High and Low Temperatures
This study proposes a car ambient lighting scheme that can withstand high and low temperature shocks while maintaining color stability across the entire operating temperature range. Currently,a microcontroller with a PWM interface is used to drive an external constant current circuit. By adjusting the PWM duty cycle,the average current level of the constant current circuit is set,which in turn controls the brightness of the LED. Since the parameters of the components in the constant current circuit are affected by temperature changes,which in turn affect the LED driving current,and since the luminous flux of the LEDs fluctuates with temperature variations,the brightness and color of the ambient lighting can vary under different temperature conditions. To address this issue,the proposed solution involves careful selection of components for the constant current circuit and the introduction of a current compensation mechanism to ensure that the car ambient lighting maintains consistent brightness and color across the entire operating temperature range.