IS31LT3953
DESCRIPTION
The IS31LT3953 is a DC-to-DC switching converter that integrates an N-channel MOSFET to operate in a buck configuration. The device can operate from a wide input voltage between 4.5V and 38V and provides a constant current of up to 3A for driving a single LED or multiple series connected LEDs.
The external resistor, RISET, is used to set a constant LED output current, while allowing the output voltage to be automatically adjusted for a variety of LED configurations.
The IS31LT3953 operates in a fixed frequency mode during switching. There is an external resistor connected between the VCC and TON pins used to configure the on-time (switching frequency). The switching frequency is dithered for spread spectrum operation which will spread the electromagnetic energy into a wider frequency band. This function is helpful for optimizing EMI performance.
A logic input PWM signal applied to the enable (EN) pin will adjust the average LED current. The LED brightness is proportional...
