COULOMB COUNTER ERROR (%)
LTC4015
Multichemistry Buck Battery Charger
Controller with Digital Telemetry System
FEATURES DESCRIPTION
n
Multichemistry Li-Ion/Polymer, LiFePO , or Lead- The LTC 4015 is a complete synchronous buck controller/
4
Acid Battery Charger with Termination charger with pin-selectable, chemistry specific charging
n
and termination algorithms.
High Efficiency Synchronous Buck Battery Charger
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Digital Telemetry System Monitors V , I ,
BAT BAT
The LTC4015 can charge Li-Ion/Polymer, LiFePO , or lead-
4
R ,NTC Ratio (Battery Temperature), V , I ,
BAT IN IN
acid batteries. Battery charge voltage is pin selectable and
V , Die Temperature
2
SYSTEM
I C adjustable. Input current limit and charge current can
n
Coulomb Counter and Integrated 14-Bit ADC
be accurately programmed with sense resistors and can
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Wide Charging Input Voltage Range: 4.5V to 35V
2
be individually adjusted via the I C serial port. A digital
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Wide Battery Voltage Range: Up to 35V
telemetry system monitors all system power parameters.
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Input Undervoltage Charge Current Limit Loop
Safety timer and current termination algorithms are sup-
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Maximum Power Point Tracking
2
ported for lithium chemistry batteries. The LTC4015 also
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Optional I C Serial Port Control
includes automatic recharge, precharge (Li-Ion) and NTC
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Input Current Limit Prioritizes System Load Output
2
thermistor protection. The LTC4015's I C port allows user
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Input and Output Ideal Diodes Provide Low Loss
customization of charger algorithms, reading of charger
PowerPath Operation
status information, configuration of the maskable and
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Instant-On Operation with Discharged Battery
programmable alerts, plus use and configuration of the
Coulomb counter.
APPLICATIONS
Available in a 38-Lead 5mm 7mm QFN package.
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Portable Medical Instruments/Military Equipment
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
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Industrial Handhelds/Lighting
PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
n property of their respective owners.
Ruggedized Notebook/Tablet Computers
TYPICAL APPLICATION
12V 2-Cell Li-Ion 8A Step-Down Battery Charger Controller
IN Step-Down Charger Efficiency and
R
SNSI
Coulomb Counter Error vs
SYS
Battery Charge Current
100 0.5
95
INFET CLP CLN SYS SYSM5
V OUTFET
IN
90 0.0
INTV
CC
UVCLFB
85
DRV
CC
SMBALERT
80 0.5
BOOST
DV
CC
CONTROLLER
75
SCL
TG
SDA 70 1.0
CELLS0 LTC4015
65
SW
EFFICIENCY
CELLS1
INTV
CC
60 1.5
QC ERROR
CELLS2
BG
55
CHEM0
50 2.0
CSPM5
CHEM1
0.1 1 10
RT
CSP CHARGE CURRENT (A)
4015 TA01b
R
SNSB
V
C
CSN
CCREFP
BATSENS
NTCBIAS
CCREFM
R
NTCBIAS
(PADDLE)
EQ
NTC
SGND GND MPPT 2P5V
CC
4015 TA01a
4015fb
1
For more information www.linear.com/LTC4015
V
IN
12V
2-CELL Li-Ion
LEAD-ACID
BATTERY
EQUALIZE
PACK
CHARGE
T
R
NTC
EFFICIENCY (%)LTC4015
TABLE OF CONTENTS
Features ............................................................................................................................ 1
Applications ....................................................................................................................... 1
Typical Application ............................................................................................................... 1
Description......................................................................................................................... 1
Absolute Maximum Ratings ..................................................................................................... 3
Order Information ................................................................................................................. 3
Data Sheet Conventions ......................................................................................................... 3
Pin Configuration ................................................................................................................. 3
Electrical Characteristics ........................................................................................................ 4
Typical Performance Characteristics .........................................................................................10
Pin Functions .....................................................................................................................13
Block Diagram ....................................................................................................................15
2
I C Timing Diagram .............................................................................................................16
Operation..........................................................................................................................17
Applications Information .......................................................................................................42
Register Description ............................................................................................................49
DETAILED Register Descriptions ..............................................................................................55
Typical Applications .............................................................................................................72
Package Description ............................................................................................................74
Revision History .................................................................................................................75
Typical Application ..............................................................................................................76
Related Parts .....................................................................................................................76
4015fb
2
For more information www.linear.com/LTC4015