ltc1760 Linear Technology Corporation, ltc1760 Datasheet - Page 18

• Manufacturer Part Number: ltc1760
• Description: Dual Smart Battery System Manager
• Manufacturer: Linear Technology Corporation

OPERATIO
LTC1760
CALIBRATE_REQUEST Bit
The read only CALIBRATE_REQUEST bit is set whenever
the LTC1760 has determined that one or more of the
connected batteries need a calibration cycle.
Allowed values are:
CHARGING_INHIBIT Bit
The read/write CHARGING_INHIBIT is used by the SMBus
Host to inhibit charging or to determine if charging is
inhibited. This bit is also set if MODE is used to inhibit
charging.
Allowed values are:
CHARGER_POR Bit
The read/write CHARGER_POR bit is used to force a
charger power on reset.
Writing a 1 to this bit will cause a charger power on reset
with the following effects.
Writing a 0 to this bit has no effect.
A read of this bit always returns a 0.
CALIBRATE Bit
The read/write CALIBRATE bit is used either to show the
status of battery calibration cycles in the LTC1760 or to
begin or end a calibration cycle.
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'b1: The LTC1760 has determined that one or both
batteries requires calibration.
'b0: The LTC1760 has determined that no batteries
require calibration.
'b1: The LTC1760 must not allow any battery charging
to occur.
'b0: The LTC1760 may charge batteries as needed,
(Power On Reset Value).
• Charging will be turned off and wake-up charging will
• The three minute wake-up watchdog timer will be
be resumed. This is the same as if the batteries were
removed and then reinserted.
restarted.
U
CALIBRATE_BAT[4:1] Nibble
The read/write CALIBRATE_BAT[4:1] nibble is used by the
SMBus Host to select the battery to be calibrated or to
determine which individual battery is being calibrated.
Allowed read values are:
Allowed write values are:
All other values will simply be ignored. This provides a
mechanism to update the other BatterySystemStateCont()
bits without altering this nibble.
2.3.3 BatterySystemInfo ()('h04)
Description:
The SMBus Host uses this command to determine the
capabilities of the LTC1760.
Purpose:
Allows the SMBus Host to determine the number of
batteries the LTC1760 supports as well as the specifica-
tion revision implemented by the LTC1760.
SMBus Protocol: Read Word
Input/Output: word — Refer to “Section 2.2” for bit
mapping.
BATTERIES_SUPPORTED Nibble
The read only BATTERIES_SUPPORTED nibble is used by
the SMBus Host to determine how many batteries the
LTC1760 can support. The two-battery LTC1760 always
returns 'b0011 for this nibble.
'b0010: Battery 2 is being calibrated . CALIBRATE must
be 1.
'b0001: Battery 1 is being calibrated. CALIBRATE must
be 1.
'b0000: No batteries are being calibrated.
'b0010: Select Battery 2 for calibration.
'b0001: Select Battery 1 for calibration.
'b0000: Allow LTC1760 to choose battery
to be calibrated.
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