LTC1760
11
1760fc
For more information
www.linear.com/LTC1760
LOPWR (Pin 12):
LOPWR Comparator Input from SCN
External Resistor Divider to GND. If the voltage at LOPWR
pin is lower than the LOPWR comparator threshold, then
system power has failed and power is autonomously
switched to a higher voltage source, if available.
DCDIV (Pin 16):
External DC Source Comparator Input
from DCIN External Resistor Divider to GND. If the
voltage at DCDIV pin is above the DCDIV comparator
threshold, then the AC_PRESENT bit is set and the wall
adapter power is considered to be adequate to charge
the batteries. If DCDIV rises more than 1.8V above V
CC
,
then all of the power path switches are latched off until
all power is removed. A capacitor from DCDIV to GND is
recommended to prevent noise-induced false emergency
turn-off conditions from being detected. Refer to “Section
8.3” and “Typical Application”.
DCIN (Pin 41):
Supply. External DC power source. A 0.1µF
bypass capacitor must be connected to this pin as close
as possible. No series resistance is allowed, since the
adapter current limit comparator input is also this pin.
Internal Power Supply Pins
V
DDS
(Pin 20):
Power Supply for SMBus Accelerators.
Also used in conjunction with MODE pin to modify the
LTC1760 operating mode.
GND (Pin 24):
Ground for Low Power Circuitry.
V
CC2
(Pin 25):
Power Supply is used Primarily to Power
Internal Logic Circuitry. Must be connected to V
CC
.
PGND (Pin 38):
High Current Ground Return for BGATE
Driver.
V
CC
(Pin 40):
Internal Regulator Output. Bypass this
output with at least a 2µF to 4.7µF capacitor. Do not use
this regulator output to supply external circuitry except
as shown in the application circuit.
SBS Interface Pins
SCL2 (Pin 17):
SMBus Clock Signal to Smart Battery 2. Do
not connect to an external pull-up. The LTC1760 connects
this pin to an internal pull-up (I
PULLUP
) when required.
SCL (Pin 18):
SMBus Clock Signal to SMBus Host. Also
used to determine flashing rate for stand-alone charge indi-
cators. Requires an external pullup to V
DDS
(normal SMBus
operating mode). Connected to internal SMBus accelerator.
SCL1 (Pin 19):
SMBus Clock Signal to Smart Battery 1. Do
not connect to an external pull-up. The LTC1760 connects
this pin to an internal pull-up (I
PULLUP
) when required.
SDA2 (Pin 21):
SMBus Data Signal to Smart Battery 2. Do
not connect to an external pull-up. The LTC1760 connects
this pin to an internal pull-up (I
PULLUP
) when required.
SDA (Pin 22):
SMBus Data Signal to SMBus Host. Also
used to indicate charging status of Battery 2. Requires
an external pullup to V
DDS
. Connected to internal SMBus
accelerator.
SDA1 (Pin 23):
SMBus Data Signal to Smart Battery 1. Do
not connect to an external pull-up. The LTC1760 connects
this pin to an internal pull-up (I
PULLUP
) when required.
MODE (Pin 26):
Used in conjunction with V
DDS
to allow
SCL, SDA and
SMBALERT
to indicate charging status. May
also be used as a hardware charge inhibit.
TH2B (Pin 27):
Thermistor Force/Sense Connection
to Smart Battery 2 SafetySignal. Connect to Battery 2
thermistor through resistor network shown in “Typical
Application.”
TH2A (Pin 28):
Thermistor Force/Sense Connection
to Smart Battery 2 SafetySignal. Connect to Battery 2
thermistor through resistor network shown in “Typical
Application.”
SMBALERT
(Pin 29):
Active Low Interrupt Pin. Signals
SMBus Host that there has been a change of status in
battery or AC presence. Open drain with weak current
source pull-up to V
CC2
(with Schottky to allow it to be
pulled to 5V externally). Also used to indicate charging
status of Battery 1.
TH1A (Pin 30):
Thermistor Force/Sense Connection
to Smart Battery 1 SafetySignal. Connect to Battery 1
thermistor through resistor network shown in “Typical
Application.”
TH1B (Pin 31):
Thermistor Force/Sense Connection
to Smart Battery 1 SafetySignal. Connect to Battery 1
thermistor through resistor network shown in “Typical
Application.”
PIN FUNCTIONS
