The LT?3653 is a monolithic current mode PWM step-down
regulator with programmable output current limit. Typically,
it is used with battery charger power path controllers to
pre-regulate the output and optimize the battery charger
effi ciency. Output current limit provides accurate control
over system power dissipation.
The wide operating input voltage range of 7.5V to 30V
suits the LT3653 to a variety of input sources, including
unregulated 12V wall adapters, 24V industrial supplies,
Firewire and automotive power. Input overvoltage protection
allows the LT3653 to handle 60V input transients.
The LT3653 control pin, VC, is available for external battery
tracking control, Bat-Track. The LT3653 will block output
discharge during an open or shorted input.
The HVOK pin indicates that the internal bias supplies
are present and no faults have occurred (i.e., overtemperature
and input overvoltage and undervoltage). The
LT3653 includes a 1.5MHz frequency oscillator, internal
compensation, and an internal boost diode to minimize the
number of external components. The LT3653 is available
in an 8-lead (2mm × 3mm) package with exposed pads
for low thermal resistance.