The LT3992 is a dual current mode PWM step-down DC/DC converter with two built-in 4.6A switches. Independent input voltage, stop, feedback, soft start, UVLO current limiting, and comparison pins for each channel simplify complex power tracking and sequencing requirements.
Typical Application
To optimize efficiency and component size, both converters feature programmable maximum current limits and are synchronized to a common external clock input or a resistance-set fixed 250 KHZ to 2MHz internal oscillator. A frequency divider is provided for channel 1 to further optimize component size. At all frequencies, a 180° phase relationship is maintained between channels, reducing voltage ripple and component size.
Block Diagram
The clock output can be used to synchronize multiple regulators. The minimum input-output voltage ratio is increased by allowing the switch to remain on for multiple clock cycles and to turn off only when the booster capacitor needs to be charged. Independent channel operations can be programmed using SHDN pins. Disabling both converters reduces the total static current＜10µA.
