LT1513/LT1513-2
SEPIC Constant- or
Programmable-Current/
Constant-Voltage Battery Charger
DESCRIPTION
FEATURES
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Charger Input Voltage May Be Higher, Equal to or The LT 1513 is a 500kHz current mode switching regula-
Lower Than Battery Voltage tor specially configured to create a constant- or program-
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Charges Any Number of Cells Up to 20V mable-current/constant-voltage battery charger. In addition
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1% Voltage Accuracy for Rechargeable Lithium to the usual voltage feedback node, it has a current sense
Batteries feedback circuit for accurately controlling output current
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100mV Current Sense Voltage for High Efficiency of a flyback or SEPIC (Single-Ended Primary Inductance
(LT1513) Converter) topology charger. These topologies allow the
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0mV Current Sense Voltage for Easy Current current sense circuit to be ground referred and completely
Programming (LT1513-2) separated from the battery itself, simplifying battery switch-
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Battery Can Be Directly Grounded ing and system grounding problems. In addition, these
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500kHz Switching Frequency Minimizes topologies allow charging even when the input voltage is
Inductor Size lower than the battery voltage. The LT1513 can also drive
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Charging Current Easily Programmable or Shut Down a CCFL Royer converter with high efficiency in floating or
grounded mode.
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APPLICATIONS
Maximum switch current on the LT1513 is 3A. This allows
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battery charging currents up to 2A for a single lithium-ion
Charging of NiCd, NiMH, Lead-Acid or Lithium
cell. Accuracy of 1% in constant-voltage mode is perfect
Rechargeable Cells
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for lithium battery applications. Charging current can be
Precision Current Limited Power Supply
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easily programmed for all battery types.
Constant-Voltage/Constant-Current Supply
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Transducer Excitation
, LTC and LT are registered trademarks of Linear Technology Corporation.
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Universal Input CCFL Driver
TYPICAL APPLICATION
Maximum Charging Current
WALL L1A*
2.4
ADAPTER
C2**
7
C3
INPUT + 4.7m F
2.2
D1
SINGLE Li-Ion CELL
22m F
5
V
IN
(4.1V)
V
25V SW 2.0
1.25A
1.8
CHARGE DOUBLE Li-Ion
L1B*
LT1513
R1
CELL (8.2V)
SYNC 1.6
2
6
AND/OR S/S V
FB
1.4
SHUTDOWN C1
SHUTDOWN GND V I +
C FB
12V
R4 R2
22m F
1.2
4 TAB13 39W
25V
16V
2
R5
1.0
270W
20V
C4 R3
0.8
C5 0.22m F 0.08W
0.1m F BATTERY
0.6
VOLTAGE
LT1513 TA01
0.4
* L1A, L1B ARE TWO 10m H WINDINGS ON A
05 10 15 20 25 30
COMMON CORE: COILTRONICS CTX10-4
INPUT VOLTAGE (V)
** CERAMIC MARCON THCR40EIE475Z OR TOKIN 1E475ZY5U-C304
INDUCTOR = 10m H
MBRD340 OR MBRS340T3. MBRD340 HAS 5A TYPICAL
ACTUAL PROGRAMMED CHARGING CURRENT WILL BE
LEAKAGE, MBRS340T3 50A TYPICAL
INDEPENDENT OF INPUT VOLTAGE IF IT DOES NOT
EXCEED VALUES SHOWN
LT1513 TA02
Figure 1. SEPIC Charger with 1.25A Output Current
sn1513 1513fas
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CURRENT (A)
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ULT1513/LT1513-2
ABSOLUTEXAI U RATI GS
Operating Junction Temperature Range
Supply Voltage ....................................................... 30V
LT1513C ............................................... 0 C to 125 C
Switch Voltage ........................................................ 40V
LT1513I ............................................ 40 C to 125 C
S/S Pin Voltage ....................................................... 30V
Short Circuit ......................................... 0 C to 150 C
FB Pin Voltage (Transient, 10ms) ......................... 10V
Storage Temperature Range ................ 65 C to 150 C
V Pin Current .................................................... 10mA
FB
I Pin Voltage (Transient, 10ms) ......................... 10V Lead Temperature (Soldering, 10 sec)................. 300 C
FB
PACKAGE/ORDER I FOR ATIO
ORDER PART ORDER PART
FRONT VIEW
NUMBER NUMBER
7 V
IN
FRONT VIEW
6 S/S
TAB 5 V V
SW 7
LT1513CR IN LT1513-2CT7
IS 4 GND S/S
6
GND 3 I LT1513-2CR V LT1513-2IT7
FB 5
SW
2 FB GND
4
LT1513IR
1 V I
C 3
FB
FB
2
LT1513-2IR
R PACKAGE
V
1 C
7-LEAD PLASTIC DD
T7 PACKAGE
T = 125 C, q = 30 C/ W
JMAX JA
7-LEAD TO-220
2
WITH PACKAGE SOLDERED TO 0.5INCH COPPER T = 125 C, q = 50 C/ W, q = 4 C/W
JMAX JA JC
AREA OVER BACKSIDE GROUND PLANE OR INTERNAL
POWER PLANE, q CAN VARY FROM 20 C/W TO
JA
> 40 C/W DEPENDING ON MOUNTING TECHNIQUE
Consult factory for Military grade parts.
LECTR AL CHARACTERIST
E IC ICS
V = 5V, V = 0.6V, V = V , I = 0V, V and S/S pins open, unless otherwise noted.
IN C FB REF FB SW
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V FB Reference Voltage Measured at FB Pin 1.233 1.245 1.257 V
REF
V = 0.8V l 1.228 1.245 1.262 V
C
FB Input Current V = V 300 550 nA
FB REF
l 600 nA
FB Reference Voltage Line Regulation 2.7V V 25V, V = 0.8V l 0.01 0.03 %/V
IN C
V I Reference Voltage (LT1513) Measured at I Pin 107 100 93 mV
IREF FB FB
V = 0V, V = 0.8V l 110 100 90 mV
FB C
I Input Current V = V (Note 2) l 10 25 35 m A
FB IFB IREF
I Reference Voltage Line Regulation 2.7V V 25V, V = 0.8V l 0.01 0.05 %/V
FB IN C
I I Voltage Offset (LT1513-2) (Note 3) I = 60m A (Note 4) l 7.5 2.5 12.5 mV
FBVOS FB VFB
I Input Current V = V l 200 10 0 nA
FB IFB IREF
V Source Current V = 10mV, V = 1.2V l 700 300 100 m A
FB IREF FB
g Error Amplifier Transconductance D I = 25m A 1100 1500 1900 m mho
m C
l 700 2300 m mho
Error Amplifier Source Current V = V 150mV, V = 1.5V l 120 200 350 m A
FB REF C
Error Amplifier Sink Current V = V + 150mV, V = 1.5V l 1400 2400 m A
FB REF C
sn1513 1513fas
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