LTC1729CMS8-4.2 Linear Technology, LTC1729CMS8-4.2 Datasheet - Page 11

• Manufacturer Part Number: LTC1729CMS8-4.2
• Description: IC CTRLR BATT CHRGR LI-ION 8MSOP
• Manufacturer: Linear Technology

Specifications of LTC1729CMS8-4.2

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIO S I FOR ATIO
the NTC pin will float to 5V as soon as the Status pull-down
is open. This will force the state machine into the Hold
mode. The V
This circuit is shown in Figure 8.
In order to restart the charging process for a new battery,
the NTC pin will need to be momentarily brought below
0.2V or the V
The automatic battery detection features are disabled
during the Hold mode.
Using Status as a Charging Indicator
In many applications circuits shown in this data sheet, the
STATUS pin is used to indicate when C/10 has occurred
(charge current has dropped to 10% of the full charge
C
CC
pin is pulled low which turns off the charger.
pin brought below the UVLO threshold.
U
U
SENSE
Figure 9. Modify C/10 Indication to Create Charging Indicator
OVP
BAT
+
–
W
SENSE
RESISTOR
200
CHARGE
CURRENT
Figure 8. Terminate Charging at C/10
U
1 F
SENSE
BAT
1
2
3
4
OVP
BAT
SENSE
GND
LTC1729-4.2
STATUS
current). This C/10 number is not fixed, but is set by an
external resistor connected to the LTC1729 SENSE pin. A
100 A bias current through this resistor develops a volt-
age which is compared with the voltage across the charge
current sense resistor. When these voltages are equal, the
open-drain STATUS pin turns off. Connecting an LED to
the STATUS pin will give a visual indication during the
precondition trickle charge and the portion of the main
charge before C/10 has occurred.
By reducing the LTC1729 SENSE pin resistor to 0 , the
STATUS pin function can be changed to a charging indica-
tor (Figure 9). The LED on the STATUS pin will always go
off after the 3-hour charge cycle is completed, regardless
of the C/10 circuitry.
–
+
I
COMP1
NTC
BIAS
V
V
CC
C
NTHS1206N02 VISHAY/DALE
8
7
6
5
10k NTC THERMISTOR
V
C
100 A
LTC1729
0.1 F
1729 F09
1729 F08
V
CC
LTC1729 Series
11