MAX1645EEI Maxim, MAX1645EEI Datasheet - Page 28

• Manufacturer Part Number: MAX1645EEI
• Description: Advanced Chemistry-Independent / Level 2 Battery Chargers with Input Current Limiting
• Manufacturer: Maxim

Advanced Chemistry-Independent, Level 2
Battery Charger with Input Current Limiting
Figure 11. Typical System Using Multiple Smart Batteries
Table 7. Smart Battery Charger Type
by SMBus Mode and Charge Algorithm
Source
Note: Level 1 smart battery chargers were defined in the ver-
sion 0.95a specification. While they can correctly interpret
smart battery end-of-charge messages, minimizing over-
charge, they do not provide truly chemistry-independent
charging. They are no longer defined by the Smart Battery
Charger Specification and are explicitly not compliant with this
and subsequent Smart Battery Charger Specifications.
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Slave only
Slave/Master
SMBus MODE
______________________________________________________________________________________
SYSTEM HOST
(SMBus HOST)
CHARGE ALGORITHM SOURCE
BATTERY
Level 2
Level 3
+12V, -12V
V
CC
BATTERY DATA/STATUS REQUESTS
CRITICAL EVENTS
SYSTEM
POWER
SUPPLY
SMART BATTERY 1
MODIFIED FROM
SMART BATTERY
SELECTOR
BATTERY
Level 3
Level 3
DC (UNREGULATED) / V
BATTERY
The Level 2 or smart battery-controlled smart battery
charger interprets the smart battery’s critical warning
messages and operates as an SMBus slave device to
respond to the smart battery’s ChargingVoltage() and
ChargingCurrent() messages. The charger is obliged to
adjust its output characteristics in direct response to
the ChargingVoltage() and ChargingCurrent() mes-
sages it receives from the battery. In Level 2 charging,
the smart battery is completely responsible for initiating
the communication and providing the charging algo-
rithm to the charger.
The smart battery is in the best position to tell the smart
battery charger how it needs to be charged. The charg-
ing algorithm in the battery may request a static charge
condition or may choose to periodically adjust the
smart battery charger’s output to meet its present
needs. A Level 2 smart battery charger is truly chem-
SMART BATTERY 2
SMBus
NOTE: SB 1 POWERING SYSTEM
SB 2 CHARGING
Level 2 Smart Battery Charger
SAFETY SIGNAL
V
SMBus
CHARGE
(UNREGULATED)
CONVERTER
CHARGER
MAX1645
BATTERY
SMART
AC-DC
AC