Demonstration circuit 923 features the LT3475 dual step-down 1.5A LED driver in a 16-lead TSSOP thermally enhanced package. The demonstration circuit is designed to drive two 1.5A LEDs on separate channels (one on each channel) from a wide input voltage range. The high switching frequency scheme permits the use of a small inductor and ceramic capacitors to save space and cost. The current mode PWM control scheme provides fast transient response and cycle-by-cycle current limiting. Frequency foldback and thermal shutdown provide additional protection. DC923A is specifically designed for high power LED applications such as automotive and avionic lighting, architectural detail lighting and display backlighting. The LT3475 has a few LED-dimming circuit options. See the datasheet for more detailed information on LED brightness and dimming control using both the PWM pin function and the VADJ pin function. The PWM terminals can be used to dim the LEDs with the addition of PWM MOSFETS and the resistor-short connections from LED- to GND removed. NOTE: The input voltage is limited to 4-30V during startup. During normal (non-startup) operation, the input voltage can be as high as 36V.