LTC4110
1
4110fb
Battery Backup
System Manager
FEATURES
APPLICATIONS
DESCRIPTION
The LTC
®
4110 is a complete single chip, high effi ciency,
fl yback battery charge and discharge manager with auto-
matic switchover between the input supply and the backup
battery or super capacitor. The IC provides four modes of
operation: battery backup, battery charge, battery calibra-
tion and shutdown. Battery backup and battery charge are
automatic standalone modes, while the optional calibration
mode requires a CPU host to communicate over an SMBus.
During calibration the fl yback charger is used in reverse
to discharge the battery with a programmable constant
current into the system load eliminating heat generation.
Three status outputs can be individually reconfi gured over
the SMBus to become GPIOs. User programmable over-
discharge protection is provided. The SHDN pin isolates
the battery to support shipping the product with a charged
battery installed.
Multiple LTC4110s can be combined to form a redundant
battery backup system or increase the number of battery
packs to achieve longer backup run times.
The LTC4110 is available in a low profi le (0.75mm), 38-pin
5mm
×
7mm QFN package. The QFN features an exposed
metal die mount pad for optimum thermal performance.
n
Complete Backup Battery Manager for Li-Ion/
Polymer, Lead Acid, NiMH/NiCd Batteries and
Super Capacitors
n
Charge and Discharge Battery with Voltages Above
and Below the Input Supply Voltage
n
“No Heat” Battery Calibration Discharge Using
System Load
n
Automatic Battery Backup with Input Supply
Removal Using PowerPath™ Control
n
Standalone for Li-Ion/Polymer, SLA, and Supercaps
n
Optional SMBus/I
2
C Support Allows Battery
Capacity Calibration Operation with Host
n
Over- and Under-Battery Voltage Protection
n
Adjustable Battery Float Voltage
n
Precision Charge Voltage ±0.5%
n
Programmable Charge/Calibration Current Up to
3A with ±3% Accuracy
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Optional Temperature Qualifi ed Charging
n
Wide Backup Battery Supply Range: 2.7V to 19V
n
Wide Input Supply Range: 4.5V to 19V
n
38-Lead (5mm
×
7mm) QFN Package
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Backup Battery Systems
n
Server Memory Backup
n
Medical Equipment
n
High Reliability Systems
Battery Backup System Manager
Server Backup System (In Backup Mode)
TYPICAL APPLICATION
L
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. PowerPath
is a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
LTC4110
INID
BATID
DCDIV
DCHFET
CHGFET
UVLO
SET POINT
BACKUP LOAD (DCOUT)
CURRENT FLOW
SYSTEM LOAD
BATTERY
DCIN
0V
ON
ON
OFF
4110 F01
4110 TA01b
LTC4110
BATTERY
BACKUP
SYSTEM
MANAGER
HOST CPU
BATTERY
SYSTEM LOAD
(DC/DC, ETC.)
I
2
C BUS
BACKUP LOAD
(MEMORY, ETC.)
CURRENT FLOW