Datasheet

LTC4100
7
4100fc
For more information www.linear.com/LTC4100
Typical perForMance characTerisTics
Charging Current Error Charging Voltage Error
CHARGING CURRENT (A)
0
OUTPUT CURRENT ERROR (A)
0.4
0.2
0.3
0.1
0
–0.1
–0.2
–0.3
–0.4
1
4100 G10
2
43
DCIN = 15V, NoLowI
DCIN = 20V, NoLowI
DCIN = 15V, LowI
DCIN = 20V, LowI
V
DD
= 5V
TEMP = 27°C
V
LOAD
= 12V
CHARGING VOLTAGE (V)
0
OUTPUT VOLTAGE ERROR (V)
0.150
0.100
0.125
0.075
0.050
0
0.025
–0.025
–0.050
–0.075
–0.100
–0.125
–0.150
16
4100 G11
42 6 10 14 18
8
12
2220
DCIN = 15V
V
DD
= 5V
TEMP = 27°C
I
LOAD
= 0.120A
DCIN = 20V
pin FuncTions
TGATE (Pin 1): Drives the Top External P-MOSFET of the
Battery Charger Buck Converter.
PGND (Pin 2): High Current Ground Return for BGATE
Driver.
BGATE (Pin 3): Drives the Bottom External N-MOSFET of
the Battery Charger Buck Converter.
INFET (Pin 4): Drives the Gate of the External Input
P-MOSFET.
DCIN (
Pin 5): External DC Power Source Input. Bypass to
ground with a 0.1µF capacitor.
CHGEN (Pin 6): Digital Bidirectional Pin to Enable Charger
Function. This pin is connected as a wired AND bus.
The following events will cause the POWER_FAIL bit in
the ChargerStatus register to become set:
1. An external device pulling the CHGEN signal to within
0.9V to GND;
2. The AC adapter voltage is not above the battery voltage.
SMBALERT (Pin 7): Active Low Interrupt Output to Host
(referred to as the SMBALERT# signal in the SMBus Revi
-
sion 1.1 specification). Signals host that there has been a
change of status in the charger registers and that the host
should read the LTC4100 status registers to determine if
any action on its part is required. This signal can be con
-
nected to the optional SMBALERT# line of the SMBus.
Open
drain with weak current source pull-up to V
DD
(with
Schottky to allow it to be pulled to 5V externally).
SDA (Pin 8): SMBus Data Signal from Main (host-
controlled) SMBus. External pull-up resistor is required.
SCL (Pin 9): SMBus Clock Signal from Main (host-
controlled) SMBus. External pull-up resistor is required.
ACP (Pin 10): This Output Indicates the Value of the
DCDIV Comparator. It can be used to indicate whether
AC is present or not.
DCDIV (Pin 11): Supply Divider Input. This is a high im
-
pedance comparator
input with a 1.2V threshold (rising
edge) and hysteresis.
GND (Pin 12): Ground for Digital and Analog Circuitry.
I
LIM
(Pin 13): An external resistor is connected between this
pin and GND. The value of the external resistor programs
the range and resolution of the programmed charger cur
-
rent. This is a digital, not an analog, function.