The PTB48560x is a series of 30-W rated isolated dc/dc converters, designed to operate from a standard -48-V telecom central office (CO) supply. Housed in a 1×2 package, each model has a wide-adjust output voltage that can be set to one of the common intermediate bus voltages of 3.3 V, 5 V, or 12 V.The PTB48560 series incorporates Auto-Track™, a feature that simplifies the power-up sequencing of multiple power modules and operates from the same intermediate bus. During a power-up cycle, modules with this feature have the capability of following a common ramp voltage applied to an input called Track. The PTB48560 series is specifically designed to control the Track voltage of any number of nonisolated downstream modules powered from its output.