LLTC4100EG View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LLTC4100EG' PDF : 30 Pages View PDF
LTC4100
Operation
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 RVLIM:
RVLIM
Short to GND
Maximum ChargingVoltage()
0x225F (8796mV)
Purpose: This function allows the SMBus Host to deter-
mine if the battery charger is an LTC4100. Identifying the
manufacturer and version of the Smart Battery Charger
permits software to perform tasks specific to a given
charger. The LTC4100 also provides a means of disabling
the LOWI current mode of the IDAC.
• SMBus Protocol: Write Word.
10kΩ ±1%
33kΩ ±1%
100kΩ ±1%
Open (or Short to VDD)
0x332F (13100mV)
0x43FF (17404mV)
0x54CF (21708mV)
0x6D5F (27996mV)
AlarmWarning() (‘h16)
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 Sta-
tus register, which is then sent to the LTC4100 by this
function.
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.
• SMBus Protocol: Write Word.
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.
Input: The NO_LOWI is the only bit recognized by this
function. The default value of NO_LOWI is zero. The
LTC4100 LOWI current mode provides a more accurate
average charge current when the charge current is less
than 1/16 of the full scale IDAC value. When the NO_LOWI
is set, a less accurate IDAC algorithm is used to generate
the charging current, but because the charger is not pulsed
on and off, it may be preferred.
• SMBus Protocol: Read Word.
Output: The NO_LOWI indicates the IDAC mode of opera-
tion. If clear, then the LOWI current mode will be used
when the charging current is less than 1/16 of the full-
scale IDAC value.
The LTC Version Identification will always be 0x202 for
the LTC4100.
Alert Response Address (ARA)
Description: The SMBus system host uses the Alert
Response Address to quickly identify the generator of an
SMBALERT# event.
Purpose: The LTC4100 will respond to an ARA address
0x18 if the SMBALERT signal is actively pulling down the
SMBALERT# bus. The LTC4100 will follow the prioritiza-
tion reporting as defined in the System Management Bus
Specification, Version 1.1, from the SBS Implementers
Forum.
• SMBus Protocol: A 7-bit Addressable Device Responds
to an ARA.
LTC0() (‘h3C)
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 Bat-
tery Charger Specification.
Output: The Device Address will be sent to the SMBus
system host. The LTC4100 Device address is 0x12.
The following events will cause the LTC4100 to pull-down
the SMBALERT# bus through the SMBALERT pin:
• Change of AC_PRESENT in the ChargerStatus()
function.
4100fc
For more information www.linear.com/LTC4100
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