© 2007 Microchip Technology Inc. DS21704B-page 1
MCP73827
Features
• Linear Charge Management Controller for Single
Lithium-Ion Cells
• High Accuracy Preset Voltage Regulation:
+
1% (max)
• Two Preset Voltage Regulation Options:
- 4.1V - MCP73827-4.1
- 4.2V - MCP73827-4.2
• Programmable Charge Current
• Automatic Cell Preconditioning of Deeply
Depleted Cells, Minimizing Heat Dissipation Dur-
ing Initial Charge Cycle
• Charge Status Output for LED Drive or Microcon-
troller Interface
• Charge Current Monitor Output
• Automatic Power-Down when Input Power
Removed
• Temperature Range: -20°C to +85°C
• Packaging: 8-Pin MSOP
Applications
• Single Cell Lithium-Ion Battery Chargers
• Personal Data Assistants
• Cellular Telephones
• Hand Held Instruments
• Cradle Chargers
•Digital Cameras
Typical Application Circuit
Description
The MCP73827 is a linear charge management con-
troller for use in space-limited, cost sensitive applica-
tions. The MCP73827 combines high accuracy
constant voltage, controlled current regulation, cell pre-
conditioning, 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 volt-
age. If the battery voltage is below the internal low-volt-
age 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 estab-
lished 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, I
MON
, 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.
Package Type
12
5
7
8
MCP73827
6
MODE
332
Ω
4
I
MON
3
+
-
GND
V
DRV
V
SNS
V
IN
V
BAT
SHDN
10 µF
100 kΩ
100 mΩ
V
IN
Single
Lithium-Ion
Cell
NDS8434MA2Q705
500 mA Lithium-Ion Battery Charger
5V
10 µF
MSOP
V
DRV
V
SNS
V
IN
V
BAT
SHDN
1
2
3
4
8
7
MCP73827
5
6
MODE
I
MON
GND
Single Cell Lithium-Ion Charge Management Controller
with Mode Indicator and Charge Current Monitor
