Precision PWM dimming LED driver reference design for automotive lighting

The TIDA-01183 TI Design details a solution on how to use pulse width modulation (PWM) to dim an automotive headlight or tail light with a precision of better than 2% duty cycle without the necessity of using a micro controller. This allows the design to be very cost competitive. Devices used in this design are the TPS92691-Q1 multi-topology LED Driver in boost and boost to battery configuration controlling the LEDs.  The TLC555-Q1 LinCMOS timer, together with the OPA2377-Q1 operational amplifier, measure and generate an accurate PWM signal by applying a feedback loop and a precision shunt regulator for setting the duty cycle accurately. The designs input stage is EMI/EMC filtered and can be directly supplied by the cars battery.

Features

• Precisioin PWM dimming
• Efficiency-optimized design
• Operation through cold crank
• Load dump tolerant

Parts Include:
OPA2377-Q1       Automotive-Qualified, Rail-to-Rail In/Out, Low Noise, 5MHz CMOS Operational Amplifier 
TL431A-Q1           Automotive Catalog Adjustable Precision Shunt Regulators 
TLC555-Q1            Automotive LinCMOS TIMER 
TPS92691-Q1       TPS92691 Multi-Topology LED Driver with Rail-to-Rail Current Sense Amplifier 

Learn more by downloading the reference design below