ADM00313 Microchip Technology, ADM00313 Datasheet - Page 17

• Manufacturer Part Number: ADM00313
• Description: Power Management IC Development Tools 73830L Li-Ion Battry Charger Eval Brd
• Manufacturer: Microchip Technology

Specifications of ADM00313

• Rohs: yes

6.0
The MCP73830 is designed to operate in conjunction
with a host microcontroller or in stand-alone applica-
tions. The MCP73830/L provides the preferred charge
FIGURE 6-1:
FIGURE 6-2:
(Li-Ion 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 Preconditioning
mode to 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
crucial to the integrity and reliability of the charging
system. The following discussion is intended as a guide
for the component selection process.
 2011 Microchip Technology Inc.
Regulated
wall cube
APPLICATIONS
Application Circuit Design
COMPONENT SELECTION
4.7µF
Typical Application Circuit.
Typical Charge Profile
Lo
Figure 6-1
1 k
Hi
4
2
5
is
V
STAT
CE
DD
MCP73830/L
algorithm for dual Lithium-Ion or Lithium-Polymer cell’s
constant current, followed by constant voltage.
Figure 6-1
circuit, while Figure
charge profile.
6.1.1.1
The preferred fast charge current for Li-Ion/Li-Poly cells
is below the 1C rate, with an absolute maximum current
at the 2C rate. The recommended fast charge
current should be obtained from the battery
manufacturer. For example, a 500 mAh battery pack
with 0.7C preferred fast charge current has a charge
current of 350 mA. Charging at this rate provides the
shortest charge cycle times without degradation to the
battery pack performance or life.
6.1.1.2
The worst-case power dissipation in the battery char-
ger occurs when the input voltage is at the maximum
and the device has transitioned from Preconditioning
mode to constant current mode. In this case, the power
dissipation is:
EQUATION 6-1:
Where:
PowerDissipation
Note:
I
V
V
REGMAX
PTHMIN
DDMAX
PROG
V
V
BAT
SS
depicts a typical stand-alone application
Please consult with your battery supplier,
or refer to the battery data sheet, for the
preferred charge rate.
Charge Current
Thermal Considerations
= the maximum input voltage
= the maximum fast charge current
= the minimum transition threshold
6
1
3
voltage
=
4.7 µF

V
MCP73830/L
6-2
DDMAX
depicts the accompanying
2 k
–
V
PTHMIN
DS25049B-page 17
+
-

1-Cell
Li-Ion
Battery

I
REGMAX