LT3652
Power Tracking 2A Battery
Charger for Solar Power
FEATURES DESCRIPTION
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Input Supply Voltage Regulation Loop for Peak The LT 3652 is a complete monolithic step-down bat-
Power Tracking in (MPPT) Solar Applications tery charger that operates over a 4.95V to 32V input
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Wide Input Voltage Range: 4.95V to 32V (40V Abs Max) voltage range. The LT3652 provides a constant-current/
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Programmable Charge Rate Up to 2A constant-voltage charge characteristic, with maximum
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User Selectable Termination: C/10 or On-Board charge current externally programmable up to 2A. The
Termination Timer charger employs a 3.3V ofl at voltage feedback reference,
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Resistor Programmable Float Voltage Up to 14.4V so any desired battery float voltage up to 14.4V can be
Accommodates Li-Ion/Polymer, LiFePO , SLA programmed with a resistor divider.
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Chemistries
The LT3652 employs an input voltage regulation loop, which
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No V Blocking Diode Required for Battery
IN
reduces charge current if the input voltage falls below a
Voltages 4.2V
programmed level, set with a resistor divider. When the
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1MHz Fixed Frequency
LT3652 is powered by a solar panel, the input regulation
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0.5% Float Voltage Reference Accuracy
loop is used to maintain the panel at peak output power.
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5% Charge Current Accuracy
n The LT3652 can be configured to terminate charging
2.5% C/10 Detection Accuracy
n when charge current falls below 1/10 of the programmed
Binary-Coded Open-Collector Status Pins
n maximum (C/10). Once charging is terminated, the LT3652
Thermally Enhanced 12-Lead 3mm 3mm DFN and
enters a low-current (85A) standby mode. An auto-re-
MSE Packages
charge feature starts a new charging cycle if the battery
APPLICATIONS
voltage falls 2.5% below the programmed float voltage.
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The LT3652 also contains a programmable safety timer,
Solar Powered Applications
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used to terminate charging after a desired time is reached.
Remote Monitoring Stations
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This allows top-off charging at currents less than C/10.
LiFePO (Lithium Phosphate) Applications
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Portable Handheld Instruments 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
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12V to 24V Automotive Systems
property of their respective owners.
Solar Panel Input Voltage
Regulation, Tracks Max Power
TYPICAL APPLICATION
Point to Greater Than 98%
2A Solar Panel Power Manager With 7.2V LiFePO Battery
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22
and 17V Peak Power Tracking
T = 25C
A
CMSH1-40MA
SOLAR PANEL INPUT 20
SYSTEM LOAD
(<40V OC VOLTAGE)
CMSH3-40MA
10F
18
100% TO 98% PEAK POWER
530k
CMSH3-40MA
V SW
IN
LT3652
1F
10H
16
V
IN_REG
BOOST
0.05
98% TO 95% PEAK POWER
100k SHDN
SENSE
14
CHRG
BAT
FAULT
10F
542k
NTC
TIMER
12
V
FB
459k
+
10k 10
B = 3380
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
CHARGER OUTPUT CURRENT (A)
2-CELL LiFePO (2 3.6V) BATTERY PACK
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3652 TA01b
3652 TA01a
3652fe
1
For more information www.linear.com/LT3652
INPUT REGULATION VOLTAGE (V)LT3652
ABSOLUTE MAXIMUM RATINGS
(Note 1)
BAT-SENSE ......................................... 0.5V to +0.5V
Voltages:
NTC, TIMER, ........................................................2.5V
V ........................................................................40V
IN
V ..........................................................................5V
V , SHDN, CHRG, FAULT ............ V + 0.5V, 40V
IN_REG IN FB
Operating Junction Temperature Range
SW ........................................................................40V
(Note 2) ............................................. 40C to 125C
SW-V .................................................................4.5V
IN
Storage Temperature Range ................... 65C to 150C
BOOST ...................................................SW+10V, 50V
BAT, SENSE ...........................................................15V
PIN CONFIGURATION
TOP VIEW
TOP VIEW
1 12 SW
V
IN
V 1 12 SW
IN
2
V 11 BOOST
IN_REG
V 2 11 BOOST
IN_REG
3
SHDN 13 10 SENSE
3
SHDN 13 10 SENSE
GND
4
9 BAT
CHRG 4 GND
CHRG 9 BAT
5 8 NTC
5 8 NTC FAULT
FAULT
TIMER 6 7 V
FB
6 7
TIMER V
FB
MSE PACKAGE
DD PACKAGE
12-LEAD PLASTIC MSOP
12-LEAD (3mm 3mm) PLASTIC DFN
T = 125C, = 43C/W, = 3C/W T = 125C, = 43C/W, = 3C/W
JMAX JA JC JMAX JA JC
EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT3652EDD#PBF LT3652EDD#TRPBF LFHT 12-Lead Plastic DFN 3mm 3mm 40C to 125C
LT3652IDD#PBF LT3652IDD#TRPBF LFHT 12-Lead Plastic DFN 3mm 3mm 40C to 125C
LT3652EMSE#PBF LT3652EMSE#TRPBF 3652 12-Lead Plastic MSOP 40C to 125C
LT3652IMSE#PBF LT3652IMSE#TRPBF 3652 12-Lead Plastic MSOP 40C to 125C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to: