LTC4100 Linear Technology, LTC4100 Datasheet - Page 12

• Manufacturer Part Number: LTC4100
• Description: Smart Battery Charger Controller
• Manufacturer: Linear Technology

LTC4100
OPERATIO
AC_PRESENT will activate the LTC4100 SMBALERT pull-
down.
Description: The Battery, System Host or other master
device sends the desired charging current (mA) to the
LTC4100 .
Purpose: The LTC4100 uses R
I
determine its charging current supplied to the battery. The
charging current will never exceed the maximum current
permitted by R
truncated to the granularity of the I
current will also be reduced if the battery voltage exceeds
the programmed charging voltage.
Input: The CHARGING_CURRENT is an unsigned 16 bit
integer specifying the requested charging current in mA.
The following table defines the maximum permissible
value of CHARGING_CURRENT that will not set the
CURRENT_OR in the ChargerStatus() function for a given
value of the R
R
Short to GND
10k
33k
Open (or short to V
Description: The Battery, SMBus Host or other master
device sends the desired charging voltage (mV) to the
LTC4100.
Purpose: The LTC4100 uses R
V
determine its charging voltage supplied to the battery. The
charging voltage will never be forced beyond the voltage
permitted by R
truncated to the granularity of the V
voltage will also be reduced if the battery current exceeds
the programmed charging current.
12
ChargingCurrent() ('h14)
DAC
ChargingVoltage() ('h15)
ILIM
DAC
• SMBus Protocol: Write Word.
• SMBus Protocol: Write Word.
, and the value of the ChargingCurrent() function to
, and the value of the ChargingVoltage() function to
1%
1%
ILIM
DD
VLIM
ILIM
) 0x0000 through 0x0FFF 0mA through 4095mA
:
U
0x0000 through 0x03FF 0mA through 1023mA
0x0000 through 0x07FF 0mA through 2047mA
0x0000 through 0x0BFF 0mA through 3071mA
. The ChargingCurrent() value will be
. The ChargingVoltage() value will be
ChargingCurrent()
VLIM
ILIM
, the granularity of the
, the granularity of the
DAC
DAC
. The charging
. The charging
Current
Input: The CHARGING_VOLTAGE is an unsigned 16-bit
integer specifying the requested charging voltage in mV.
The LTC4100 considers any value from 0x0001 through
0x049F the same as writing 0x0000. The following
table defines the maximum permissible value of
CHARGING_VOLTAGE that will not set the VOLTAGE_OR
in the ChargerStatus() function for a given value of R
R
Short to GND
10k
33k
100k
Open (or short to V
Description: The Smart Battery, acting as a bus master
device, sends the AlarmWarning() message to the LTC4100
to notify it that one or more alarm conditions exist. Alarm
indications are encoded as bit fields in the Battery’s Status
register, which is then sent to the LTC4100 by this func-
tion.
Purpose: The LTC4100 will use the information sent by
this function to properly charge the battery. The LTC4100
will only respond to certain alarm bits. Writing to this
function does not necessarily cause an alarm condition
that inhibits battery charging.
Input: Only the OVER_CHARGED_ALARM, TERMINATE
_CHARGE_ALARM,reserved (0x2000), and OVER
_TEMP_ALARM bits are supported by the LTC4100.
Writing a one to any of these specified bits will inhibit
the charging by the LTC4100 and will set the
ALARM_INHIBITED bit in the ChargerStatus() function. The
TERMINATE_DISCHARGE_ALARM, REMAINING_
CAPACITY_ALARM, REMAINING_TIME_ALARM, and the
ERROR bits are ignored by the LTC4100.
Description: The SMBus Host uses this command to
determine the version number of the LTC4100 and set
extended operation modes not defined by the Smart
Battery Charger Specification.
AlarmWarning() ('h16)
LTC0() ('h3C)
VLIM
• SMBus Protocol: Write Word.
1%
1%
1%
DD
)
Maximum ChargingVoltage()
0x54CF (21708mV)
0x6D5F (27999mV)
0x332F (13100mV)
0x43FF (17404mV)
0x225F (8796mV)
sn4100 4100is
VLIM
: