Buck controller with 100% duty cycle for low-dropout regulation
The LTC1771IS8#PBF is a step-down (buck) switching regulator controller from Analog Devices, designed for applications where the output voltage must be regulated down from a supply rail as low as 2.8V. Its 100% maximum duty cycle means the top-side MOSFET can stay on continuously — useful when the input voltage drops close to the output target, such as in battery-powered systems where the supply decays below the regulation point and the controller passes the input straight through without dropping out.
The controller operates from a Vcc supply of 2.8V to 18V, covering common 3.3V, 5V, and 12V input rails.
Package and sourcing posture
Housed in an 8-lead SOIC package (0.154" width, 3.90 mm), the LTC1771IS8#PBF is supplied in tube format. The supplier device package is 8-SO. Lifecycle status is Active, and the part is ROHS3 compliant.