LX2203AILD MICROSEMI [Microsemi Corporation], LX2203AILD Datasheet - Page 8

• Manufacturer Part Number: LX2203AILD
• Description: Li-Ion Battery Charger
• Manufacturer: MICROSEMI [Microsemi Corporation]

Copyright © 2004
Rev. 1.0a, 2005-10-21
Ion (Li-ion) battery using two modes: a constant current
mode, where the charge current is held constant and the
battery terminal voltage rises to 4.2V; this is followed by
constant voltage mode, where the battery voltage is held at
4.2V and the charge current starts to taper off. Once the taper
current reaches the charge termination current level the
charge cycle is ended and the STAT indicator turns off. If
the fully charged battery terminal voltage drops to 4.07V, the
battery charge cycle will be restarted.
voltage is less than 2.65V, the battery charger will reduce the
charge current to 5%. This also protects the appliance from
overheating by trying to drive the full charging current into a
damaged battery.
until the VIN voltage rises above 4.2V. Hysteresis prevents
chattering on and off.
charger becomes excessive, the charge current will be
reduced to prevent the die temperature from getting above
150°C. This does not cause the charge cycle to stop.
will not flow from the battery through the charger.
external blocking diode is required on the input.
removed, the charger enters a sleep mode where a very low
quiescent current prevents drain from the battery.
10µF ceramic capacitors close to the VIN and V
terminals to filter switching transients.
path from the thermal pad on the bottom of the LX2203A
package to the ground plane of the circuit board to maximize
the heat dissipation. To minimize charge time it is best not to
rely on the thermal control feature as this feature will extend
the charging time when activated.
G
P
L
ROTECTION
AYOUT
ENERAL
The LX2203A is designed to charge a single cell Lithium
Conditioning Current Mode – If the battery terminal
Under Voltage Lockout – The charge cycle will not start
Thermal Control loop – If the power dissipation of the
Reverse current blocking – If VIN is grounded, current
Sleep Mode – If the EN pin is logic low or if VIN is
•
•
It is important when laying out the LX2203A to place
It is important to provide a low thermal impedance
TM
G
D
UIDELINES
ESCRIPTION
F
EATURES
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
A P P L I C A T I O N N O T E
Integrated Products Division
®
Microsemi
BAT
No
IC
current) is set by selecting a value for the CTP resistor using
the following formula:
= 150k.
ranging from 20mA to 500mA.
levels for different charge rates. For a “quick charge”, the
termination current can be set to about 50% of the constant
current level; this charges the battery to about 75% capacity.
For a full charge (taking several hours) the termination
current can be set to 5% of the constant current level. The
circuit below allows switching between the two levels:
mode is programmable by controlling the current flowing
from the CCP pin. A graph showing this relationship is
included in this specification. The CCP pin is regulated to
1.25V when the charger is active. Connecting a resistor from
the CTP to ground will produce a CTP current of:
T
C
ERMINATION
ONSTANT
The charge termination current (or minimum taper
For example, for a termination current of 50mA set R
It is possible to change the termination current to different
The charge current during the constant current charge
R
I
(Continued on next page)
CTP
CTP
Figure 5 – 500mA or 50mA termination current
=
=
R
Quick/Slow
1.25
I
7500
TERM
CCP
This formula applies to termination currents
C
Li-Ion Battery Charger
P
HARGE
RODUCTION
C
URRENT
C
URRENT
P
ROGRAMMING
D
ATA
16.5k
P
ROGRAMMING
S
HEET
150k
LX2203A
CTP
CTP
Page 8