The MCP73827 is a linear charge management controller
for use in space-limited, cost sensitive applications.
The MCP73827 combines high accuracy
constant voltage, controlled current regulation, cell preconditioning,
and charge status indication in a space
saving 8-pin MSOP package. The MCP73827 provides
a stand-alone charge management solution.
The MCP73827 charges the battery in three phases:
preconditioning, controlled current, and constant voltage.
If the battery voltage is below the internal low-voltage
threshold, the battery is preconditioned with a
foldback current. The preconditioning phase protects
the lithium-ion cell and minimizes heat dissipation.
Following the preconditioning phase, the MCP73827
enters the controlled current phase. The MCP73827
allows for design flexibility with a programmable charge
current set by an external sense resistor. The charge
current is ramped up, based on the cell voltage, from
the foldback current to the peak charge current established
by the sense resistor. This phase is maintained
until the battery reaches the charge-regulation voltage.
Then, the MCP73827 enters the final phase, constant
voltage. The accuracy of the voltage regulation is better
than +1% over the entire operating temperature range
and supply voltage range. The MCP73827-4.1 is preset
to a regulation voltage of 4.1V, while the
MCP73827-4.2 is preset to 4.2V. The charge status
output, MODE, indicates when the charge cycle has
transitioned to constant voltage mode. The charge
cycle can be terminated by a timer that is started when
the MODE pin goes to a logic High or by monitoring the
charge current monitor output, IMON, for a minimum
current.
The MCP73827 operates with an input voltage range
from 4.5V to 5.5V. The MCP73827 is fully specified
over the ambient temperature range of -20°C to +85°C.