DESIGN FEATURES L Highly Integrated USB Power Manager
with Li-Ion Charger and Three
Step-Down Switching Regulators
in 4mm Г— 4mm QFN
by Amit Lele
Introduction
Mobile technology has radically
changed the way we acquire, share
and disseminate information. Modern,
feature-rich handheld and portable
devices require several power management circuits, including a battery
charger, multiple step-down switching
regulators and low power LDOs for
watchdog circuitry. If each of these
functions is served by a separate power
supply IC, each IC (and its external
components) occupies valuable board
space, consumes battery-draining
quiescent current and significantly
increases the overall development and material costs of the device. The
LTC3557 solves this problem by bringing all power management functions
into a single device. It combines a full
featured USB power manager, a Li-ion …