ltc4096 Linear Technology Corporation, ltc4096 Datasheet - Page 11

• Manufacturer Part Number: ltc4096
• Description: Dual Input Standalone Li-ion Battery Chargers
• Manufacturer: Linear Technology Corporation

APPLICATIONS INFORMATION
Manual Shutdown
The SUSP pin has a 3.4MΩ pulldown resistor to GND. A
logic low enables the charger and logic high disables it
(the pulldown defaults the charger to the charging state).
The DCIN input draws 20µA when the charger is in shut-
down. The USBIN input draws 20µA during shutdown if
no power is applied to DCIN, but draws only 10µA when
V
Thermal Limiting
An internal thermal feedback loop reduces the programmed
charge current if the die temperature attempts to rise
DCIN
> V
SUSP
DRIVEN LOW
*NOT PRESENT IN THE "X" VERSION
USBIN
BAT < 2.9V
2.9V < BAT
BAT < 4.15V
.
IN VOLTAGE MODE
I
BAT
< I
CHRG STATE: PULLDOWN
CHRG STATE: PULLDOWN
BAT > 2.9V
TERMINATE
NO CHARGE CURRENT
1/10th FULL CURRENT
I
DCIN
TRICKLE CHARGE*
PWR STATE: DCIN
PWR STATE: DCIN
CHRG STATE: Hi-Z
PWR STATE: DCIN
CHRG STATE: Hi-Z
PWR STATE: DCIN
FULL CURRENT
SHUTDOWN
DROPS TO 20µA
STANDBY
CHARGE
MODE
MODE
MODE
MODE
DCIN POWER APPLIED
Figure 1. LTC4096 State Diagram of a Charge Cycle
DCIN POWER
REMOVED
SUSP
DRIVEN HIGH
DCIN POWER
REMOVED
POWER SELECTION
STARTUP
above a preset value of approximately 115°C. This feature
protects the LTC4096 from excessive temperature and
allows the user to push the limits of the power handling
capability of a given circuit board without risk of damag-
ing the device. The charge current can be set according
to typical (not worst case) ambient temperature with the
assurance that the charger will automatically reduce the
current in worst case conditions. A safety thermal shut
down circuit will turn off the charger if the die temperature
rises above a value of approximately 150°C. DFN power
considerations are discussed further in the Applications
Information section.
SUSP
DRIVEN HIGH
USBIN POWER
REMOVED OR
DCIN POWER
APPLIED
USBIN POWER
REMOVED OR
DCIN POWER
ONLY USB POWER APPLIED
APPLIED
LTC4096/LTC4096X
CHRG STATE: PULLDOWN
CHRG STATE: PULLDOWN
I
1/10th FULL CURRENT
NO CHARGE CURRENT
USBIN
PWR STATE: USBIN
PWR STATE: USBIN
PWR STATE: USBIN
TRICKLE CHARGE*
PWR STATE: USBIN
CHRG STATE: Hi-Z
CHRG STATE: Hi-Z
FULL CURRENT
SHUTDOWN
DROPS TO 20µA
STANDBY
CHARGE
MODE
MODE
MODE
MODE
I
IN VOLTAGE MODE
BAT > 2.9V
BAT
< I
TERMINATE
4096 F01
BAT < 4.15V
SUSP
DRIVEN LOW
BAT < 2.9V
2.9V < BAT
11
4096xf