The MCP73871 device is a fully integrated linear
solution for system load sharing and Li-Ion / Li-Polymer
battery charge management with ac-dc wall adapter
and USB port power sources selection. It’s also
capable of autonomous power source selection
between input or battery. Along with its small physical
size, the low number of required external components
makes the device ideally suited for portable
applications.
The MCP73871 device automatically obtains power for
the system load from a single-cell Li-Ion battery or an
input power source (ac-dc wall adapter or USB port).
The MCP73871 device specifically adheres to the
current drawn limits governed by the USB specification.
With an ac-dc wall adapter providing power to the
system, an external resistor sets the magnitude of 1A
maximum charge current while supports up to 1.8A
total current for system load and battery charge
current.
The MCP73871 device employs a constant current /
constant voltage (CC/CV) charge algorithm with selectable
charge termination point. The constant voltage
regulation is fixed with four available options: 4.10V,
4.20V, 4.35V, or 4.40V to accommodate new, emerging
battery charging requirements. The MCP73871 device
also limits the charge current based on die temperature
during high power or high ambient conditions. This
thermal regulation optimizes the charge cycle time
while maintaining device reliability.
The MCP73871 device includes a low battery indicator,
a power-good indicator and two charge status indicators
that allows for outputs with LEDs or communication
with host microcontrollers. The MCP73871 device
is fully specified over the ambient temperature range of
-40°C to +85°C.