LTC4065EDC Linear Technology, LTC4065EDC Datasheet - Page 12

• Manufacturer Part Number: LTC4065EDC
• Manufacturer: Linear Technology

Specifications of LTC4065EDC

• Battery Type: Li-Ion
• Output Current: 500mA
• Output Voltage: 4.2V
• Operating Supply Voltage (min): 3.75V
• Operating Supply Voltage (max): 5.5V
• Operating Temp Range: -40C to 85C
• Mounting: Surface Mount
• Pin Count: 6
• Operating Temperature Classification: Industrial
• Lead Free Status / Rohs Status: Not Compliant

OPERATIO
LTC4065/LTC4065A
Transconductance amplifier, TA, limits the die tempera-
ture to approximately 115°C when in constant-tempera-
ture mode. Diode D3 ensures that TA does not affect the
charge current when the die temperature is below approxi-
mately 115°C. The PROG pin voltage continues to give an
indication of the charge current.
In typical operation, the charge cycle begins in constant-
current mode with the current delivered to the battery
equal to 1000V/R
12
POWER
U
ON
PROG
. If the power dissipation of the
1/4 CHARGE CYCLE
(1.125 HOURS)
THRESHOLD
IS EN > SHUTDOWN
THRESHOLD?
CHRG HIGH IMPEDANCE
1/10 FULL CHARGE CURRENT
CHRG STRONG PULL-DOWN
IS V
NO CHARGE CURRENT
CHRG PULSES (2Hz)
EN > SHDN
V
TRICKLE CHARGE MODE
CC
BAT
DEFECTIVE BATTERY
BAD BATTERY MODE
OR
SHUTDOWN MODE
< 3V
< 2.9V?
ENABLE
Figure 2. State Diagram of LTC4065 Operation
YES
V
YES
BAT
≤ 2.9V
NO
NO
1/2 CHARGE CYCLE
CHARGE CYCLE
(2.25 HOURS)
(4.5 HOURS)
IF V
V
FULL CHARGE CURRENT
CHRG STRONG PULL-DOWN
IS V
FULL CHARGE CURRENT
CHRG STRONG PULL-DOWN
CC
CC
BAT
> V
FAST CHARGE MODE
RECHARGE MODE
> 3.6V AND
BAT
< 4.1V?
LTC4065/LTC4065A results in the junction temperature
approaching 115°C, the amplifier (TA) will begin decreas-
ing the charge current to limit the die temperature to
approximately 115°C. As the battery voltage rises, the
LTC4065/LTC4065A either return to constant-current mode
or enter constant-voltage mode straight from constant-
temperature mode. Regardless of mode, the voltage at
the PROG pin is proportional to the current delivered to
the battery.
RECHARGE
+ 80mV?
UVLO
2.9V < V
YES
YES
BAT
< 4.1V
NO
NO
CHRG HIGH IMPEDANCE
NO CHARGE CURRENT
CHRG HIGH IMPEDANCE
STANDBY MODE
UVLO MODE
V
BAT
> 4.1V
4065 F02
4065fb