MCP73832T-2ACI/OT Microchip Technology Inc., MCP73832T-2ACI/OT Datasheet - Page 13

• Manufacturer Part Number: MCP73832T-2ACI/OT
• Description: TINY INTEGRATED LI-ION/LI-POLY CHARGE MGNT CONTROLLER, 4.2V VREG
• Manufacturer: Microchip Technology Inc.

Specifications of MCP73832T-2ACI/OT

• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

6.0
The MCP73831/2 are designed to operate in conjunc-
tion with a host microcontroller or in a stand-alone
application. The MCP73831/2 provide the preferred
charge algorithm for Lithium-Ion and Lithium-Polymer
FIGURE 6-1:
FIGURE 6-2:
(180 mAh Battery).
6.1
Due to the low efficiency of linear charging, the most
important factors are thermal design and cost, which
are a direct function of the input voltage, output current
and thermal impedance between the battery charger
and the ambient cooling air. The worst-case situation
is when the device has transitioned from the
Preconditioning mode to the Constant-Current mode.
In this situation, the battery charger has to dissipate
the maximum power. A trade-off must be made
between the charge current, cost and thermal
requirements of the charger.
6.1.1
Selection of the external components in Figure 6-1 is
crucial to the integrity and reliability of the charging
system. The following discussion is intended as a
guide for the component selection process.
© 2006 Microchip Technology Inc.
6.0
5.0
4.0
3.0
2.0
1.0
0.0
APPLICATIONS
Application Circuit Design
COMPONENT SELECTION
MCP73831-2AC/IOT
V
R
DD
PROG
REGULATED
WALL CUBE
= 5.2V
= 10 k Ω
Time (minutes)
Typical Application Circuit.
Typical Charge Profile
C
IN
120
100
80
60
40
20
0
R
LED
LED
Li-Ion Battery Charger
4
1
V
STAT
DD
MCP73831
cells constant current followed by constant voltage.
Figure 6-1 depicts a typical stand-alone application
circuit,
accompanying charge profile.
FIGURE 6-3:
Thermal Regulation (1000 mAh Battery).
6.1.1.1
The preferred fast charge current for Lithium-Ion cells
is at the 1C rate, with an absolute maximum current at
the 2C rate. For example, a 500 mAh battery pack has
a preferred fast charge current of 500 mA. Charging at
this rate provides the shortest charge cycle times
without degradation to the battery pack performance
or life.
PROG
6.0
5.0
4.0
3.0
2.0
1.0
0.0
V
V
BAT
SS
while
MCP73831-2AC/IOT
V
R
DD
PROG
3
5
2
= 5.2V
Current Programming Resistor
(R
= 2 k Ω
PROG
Figures 6-2
R
Time (minutes)
C
MCP73831/2
)
PROG
Typical Charge Profile in
OUT
and 6-3
+
-
Single
Li-Ion
Cell
DS21984B-page 13
depict
600
500
400
300
200
100
0
the