LTC4015_15 Datasheet, PDF (1/76 Pages) Linear Technology – Multichemistry Buck Battery Charger Controller with Digital Telemetry System

LTC4015
Multichemistry Buck Battery
Charger Controller with Digital Telemetry System
Features
n _{Multichemistry Li-Ion/Polymer, LiFePO4, or Lead-}
Acid Battery Charger with Termination
n _{High Efficiency Synchronous Buck Battery Charger}
n _{Digital Telemetry System Monitors VBAT, IBAT,}
R_BAT,NTC Ratio (Battery Temperature), V_IN, I_IN,
V_SYSTEM, Die Temperature
n _{Coulomb Counter and Integrated 14-Bit ADC}
n _{Wide Charging Input Voltage Range: 4.5V to 35V}
n _{Wide Battery Voltage Range: Up to 35V}
n _{Input Undervoltage Charge Current Limit Loop}
n _{Maximum Power Point Tracking}
n _{Optional I}²_{C Serial Port Control}
n _{Input Current Limit Prioritizes System Load Output}
n _{Input and Output Ideal Diodes Provide Low Loss}
PowerPath™ Operation
n _{Instant-On Operation with Discharged Battery}
Applications
n _{Portable Medical Instruments/Military Equipment}
n _{Industrial Handhelds/Lighting}
n _{Ruggedized Notebook/Tablet Computers}
Description
The LTC^®4015 is a complete synchronous buck controller/
charger with pin selectable, chemistry specific charging
and termination algorithms.
The LTC4015 can charge Li-Ion/Polymer, LiFePO₄, or lead-
acid batteries. Battery charge voltage is pin selectable and
I²C adjustable. Input current limit and charge current can
be accurately programmed with sense resistors and can
be individually adjusted via the I²C serial port. A digital
telemetry system monitors all system power parameters.
Safety timer and current termination algorithms are sup-
ported for lithium chemistry batteries. The LTC4015 also
includes automatic recharge, precharge (Li-Ion) and NTC
thermistor protection. The LTC4015's I²C port allows user
customization of charger algorithms, reading of charger
status information, configuration of the maskable and
programmable alerts, plus use and configuration of the
Coulomb counter.
Available in a 38-Lead 5mm × 7mm QFN package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
Typical Application
12V_IN 2-Cell Li-Ion 8A Step-Down Battery Charger Controller
V_IN
R_SNSI
12V
SYS
µCONTROLLER
INTV_CC
LEAD-ACID
EQUALIZE
CHARGE
V_IN ^{INFET CLP}
UVCLFB
SMBALERT
DV_CC
SCL
SDA
CELLS0
CELLS1
CELLS2
CHEM0
CHEM1
RT
V_C
CCREFP
CCREFM
EQ
SGND
CLN SYS SYSM5 _OUTFET
INTV_CC
DRV_CC
BOOST
TG
LTC4015
(PADDLE)
GND
SW
BG
2P5V_CC
CSPM5
CSP
CSN
BATSENS
NTCBIAS
MPPT ^NTC
MPPT
ENABLE
R_SNSB
2-CELL Li-Ion
R_NTCBIAS BATTERY
PACK
T
R_NTC
4015 TA01a
For more information www.linear.com/LTC4015
Step-Down Charger Efficiency and
Coulomb Counter Error vs
Battery Charge Current
100
0.5
95
90
0.0
85
80
75
70
65
60
55
50
0.1
–0.5
–1.0
EFFICIENCY
QC ERROR
–1.5
1
CHARGE CURRENT (A)
–2.0
10
4015 TA01b
4015f
1