ltc4096 Linear Technology Corporation, ltc4096 Datasheet - Page 7

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

PIN FUNCTIONS
TYPICAL PERFORMANCE CHARACTERISTICS
DCIN (Pin 1): Wall Adapter Input Supply Pin. Provides
power to the battery charger. The maximum supply
current is 1.2A. This pin should be bypassed with a 1µF
capacitor.
USBIN (Pin 2): USB Input Supply Pin. Provides power to
the battery charger. The maximum supply current is 1A.
This pin should be bypassed with a 1µF capacitor.
PWR (Pin 3): Power Present Output. When the DCIN or
USBIN pin voltage is suffi cient to begin charging (i.e. when
the DCIN or USBIN supply is greater than the undervoltage
lockout thresholds and at least 100mV or 150mV, re-
spectively, above the battery terminal), the PWR pin is
connected to the appropriate input through an internal
P-channel MOSFET. If suffi cient voltage to charge is not
present on DCIN or USBIN the PWR pin is high impedance.
This output is able to source up to 120mA.
⎯ C ⎯ H ⎯ R ⎯ G (Pin 4): Open-Drain Charge Status Output. When
the LTC4096 is charging, the ⎯ C ⎯ H ⎯ R ⎯ G pin is pulled low by
an internal N-channel MOSFET. When the charge cycle is
completed, ⎯ C ⎯ H ⎯ R ⎯ G becomes high impedance. This output
is capable of sinking up to 10mA, making it suitable for
driving an LED.
60
50
40
30
20
10
0
–50
Shutdown Supply Current vs
Temperature and V
SUSP = V
V
DCIN
–25
= 0V
USBIN
TEMPERATURE (°C)
0
V
USBIN
25
USBIN
= 5.5V
V
50
USBIN
= 4.25V
75
4096 G28
100
SUSP (Pin 5): Charge Enable Input. A logic low on this
pin enables the charger. If left fl oating, an internal 3.4MΩ
pull-down resistor defaults the LTC4096 to charge mode.
Pull this pin high for shutdown.
ITERM (Pin 6): Charge Termination Current Threshold
Program. The termination current threshold, I
set by connecting a resistor, R
is set by the following formula:
When the battery current, I
threshold, charging stops and the ⎯ C ⎯ H ⎯ R ⎯ G output becomes
high impedance.
IUSB (Pin 7): Charge Current Program for USB Power.
The charge current is set by connecting a resistor, R
to ground. When charging in constant-current mode, this
pin servos to 1V. The voltage on this pin can be used to
measure the battery current delivered from the USBIN
input using the following formula:
I
I
BAT
TERMINATE
4.10
4.05
4.00
3.95
3.90
3.85
3.80
3.75
3.70
=
–50
Undervoltage Lockout Voltage
(Falling) vs Temperature
R
V
IUSB
IUSB
T
A
–25
= 25°C, unless otherwise noted.
=
• 1000
R
LTC4096/LTC4096X
USBIN UVLO
TEMPERATURE (°C)
100
ITERM
0
DCIN UVLO
V
25
BAT
50
ITERM
, falls below the termination
75
, to ground. I
4096 G29
100
TERMINATE
TERMINATE
IUSB
4096xf
7
, is
,