DESCRIPTION
Demonstration circuit 2879A is a high efficiency, high
power density hybrid converter. It can deliver 12V/25A
with an input voltage from 36V to 60V (up to 65V during
transients). This demo board features the LTM®4660,
which uses an architecture that merges soft-switching
switched capacitor topology with a traditional step-down
converter to provide superior efficiency compared to the
traditional switching architectures. It offers a high efficiency/
high density and cost effective solution for nonisolated
intermediate bus applications in power distribution,
datacom and telecom.
Due to its current mode control architecture, multiple
LTM4660s can be operated in a parallel, multiphase configuration
with excellent current sharing and low output
voltage ripple to enable much higher power applications.
Other benefits include low EMI emissions due to a softswitched
front end and reduced MOSFET stress.
The LTM4660 design eliminates the inrush current typically
associated with switched capacitor circuits by prebalancing
the capacitors on start-up. The LTM4660 also
monitors system voltage, current and temperature for
faults. It stops switching and pulls the FAULT pin low
when a fault condition occurs. An onboard timer can be
set for appropriate restart/retry times.
Additional features include ±1.5% output voltage accuracy
over temperature, a clock output for multiphase
operation, a power good output signal, short-circuit protection,
monotonic output voltage start-up, optional external
reference, undervoltage lockout and internal charge
balance circuitry.
The LTM4660 data sheet must be used in conjunction
with this demo board manual.