GENERAL DESCRIPTION
The LT®8673 is an active rectifier controller for reverse
input protection that includes two independent low IQ
comparators with programmable glitch rejection filters
for cold start pulse detection and two voltage monitoring
protection pins to sense the battery voltage safely using
an external resistive divider and ADC (analog-to-digital
converter). The highly integrated comparators and active
rectifier solution greatly simplify the Bill of Materials
(BOM) and shrinks the printed circuit board (PCB) area.
The controller drives an external N-channel Metal-oxide
semiconductor field-effect transistor (MOSFET) to replace
a power Schottky diode. Its very low quiescent current
and fast transient response meet the tough requirements
in automotive applications where AC input signals of up
to 100kHz are present. These signals are rectified with
minimum power dissipation on the external MOSFET,
simplifying thermal management on the PCB.
With a drop of only 20mV, the LT8673 solution eases the
minimum input voltage requirement during cold crank
and start-stop, allowing simpler and more efficient circuits.
A fast turn-off minimizes reverse current transients
if the input power source fails or is shorted. An available
shutdown mode reduces the quiescent current to 3.8μA.
An integrated auxiliary boost regulator provides the
required boost voltage to turn the external MOSFET fully
on. A FAULT pin signals if the external FET is not ready to
take load current.

FEATURES
 Reverse Input Protection to -40V
 Improved Performance Compared to a Schottky
Diode
 Reduce Power Dissipation by > 90%
 Reduce Drop to 20mV
 Ultrafast Transient Response
Rectifies 6VP-P Up to 50kHz
Rectifies 2VP-P Up to 100kHz
 Wide Operating Voltage Range: 3V to 42V
 Two Integrated Comparators for Cold Crank
Detection
 Programmable Anti-glitch Filters
 Dedicated Enable Pin (ENR)
 Voltage Monitoring Protection Pins
 Low 55μA Quiescent Current in Operation
 Low 3.8μA Shutdown Current
 Accurate 1.2V Enable Pin Threshold
 Small 20-Lead 3mm x 4mm Side-Wettable Quad Flat
No-Lead (QFN) Package
 AEC-Q100 Qualified for Automotive Applications

APPLICATIONS
 Automotive Battery Protection
 Industrial Supplies
 Portable Instrumentation