LTC4063 LINER [Linear Technology], LTC4063 Datasheet - Page 13

• Manufacturer Part Number: LTC4063
• Description: Standalone Linear Li-Ion Charger with Micropower Low Dropout Linear Regulator
• Manufacturer: LINER [Linear Technology]

APPLICATIO S I FOR ATIO
Charge Current Termination
Connecting the TIMER pin to ground selects Charge
Current Termination. With this method, the timer is
disabled and a resistor (R
the IDET pin to ground. I
same equation stated in the previous section (repeated
here for convenience):
The charge cycle terminates when the charge current falls
below I
nal, filtered comparator to monitor the IDET pin. When the
IDET pin falls below 100mV for longer than t
cally 1.5ms), charging is terminated.
When charging, transient loads on the BAT pin can cause
the IDET pin to fall below 100mV for short periods of time
before the DC current has dropped below the I
threshold. The 1.5ms filter time (t
or
I
R
DETECT
DET
DETECT
=
I
=
DETECT
100
10
R
. This condition is detected using an inter-
PROG
R
V
DET
U
•
I
CHG
POWER ON
DETECT
U
Figure 4. State Diagram of a Charge Cycle Using Charge Current Termination
DET
=
) must be connected from
100
R
is programmed using the
DET
V
W
TERM
2.9V < BAT < 4.1V
BAT < 4.1V
BAT > 4.1V
) on the internal
BAT < 2.9V
TERM
U
CHRG STATE: PULL-DOWN
CHRG STATE: PULL-DOWN
CHRG STATE: Hi-Z
DETECT
TRICKLE CHARGE MODE
NO CHARGE CURRENT
(typi-
1/10 FULL CURRENT
STANDBY MODE
CHARGE MODE
FULL CURRENT
BAT > 2.9V
I
IN VOLTAGE MODE
BAT
comparator ensures that transient loads of this nature do
not result in premature charge cycle termination. Once the
average charge current drops below I
terminates the charge cycle.
The CHRG output is in its pull-down state when charging
and in its high impedance state once charging has stopped.
Figure 4 describes the operation of the LTC4063 charger
when charge current termination is used.
User-Selectable Charge Termination
Connecting the TIMER pin to V
Charge Termination, in which all internal termination
features are disabled. The charge cycle continues indefi-
nitely until the charger is shut down through the CHGEN
pin. The IDET pin programs the behavior of the CHRG
output in the same manner as when using Charge Time
Termination. Specifically, when the charge current (I
is greater than I
state. When the charger enters constant-voltage mode
operation and the charge current falls below I
CHRG output becomes high impedance, indicating that
the battery is charged. If the IDET pin is not connected, the
CHRG output remains in its pull-down state until the
charger is shut down.
< I
DETECT
4063 F04
DETECT
UVLO CONDITION
CHGEN = 5V
CHRG STATE: Hi-Z
OR
I
SHUTDOWN MODE
CC
, the CHRG output is in its pull-down
DROPS TO 35µA
CHGEN = 0V
OR UVLO
CONDITION
STOPS
CC
selects User-Selectable
DETECT
LTC4063
, the charger
DETECT
13
, the
BAT
4063fb
)