LT1767-1.8

Input Voltage ........................................................  25V
BOOST Pin Above SW ............................................  20V
Max BOOST Pin Voltage .......................................... 35V
SHDN Pin ...............................................................  25V
FB Pin Voltage .........................................................  6V
FB Pin Current .......................................................  1mA
SYNC Pin Current ..................................................  1mA
Operating Junction Temperature Range (Note 2)
LT1767E................................................  40 to 125
Storage Temperature Range..................65 to 150
Lead Temperature (Soldering, 10 sec).................. 300

The LT^®1767 is a 1.25MHz monolithic buck switchingregulator. A high efficiency 1.5A, 0.22W  switch is includedon the die together with all the control circuitry required tocomplete a high frequency, current mode switching regu-lator. Current mode control provides fast transient re-sponse and excellent loop stability.

New design techniques of LT1767 achieve high efficiency at highswitching frequencies over a wide operating range. A low ropout internal regulator maintains consistent perfor-mance over a wide range of inputs from 24V systems to Li-Ion batteries. An operating supply current of 1mA im-proves efficiency, especially at lower output currents.Shutdown reduces quiescent current to 6m A. Maximumswitch current remains constant at all duty cycles. Syn-chronization allows an external logic level signal to in-crease the internal oscillator from 1.4MHz to 2MHz.

The LT1767 is available in an 8-pin MSOP fused leadframepackage and a low thermal resistance exposed pad pack-age. Full cycle-by-cycle short-circuit protection and ther-mal shutdown are provided. High frequency operationallows the reduction of input and output filtering compo-nents and permits the use of chip inductors.