Datasheet LT1512 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | SEPIC Constant-Current/Constant-Voltage Battery Charger |
| Pages / Page | 14 / 1 — FeaTures. DescripTion. Charger Input Voltage May Be Higher, Equal to or. … |
| File Format / Size | PDF / 211 Kb |
| Document Language | English |
FeaTures. DescripTion. Charger Input Voltage May Be Higher, Equal to or. Lower Than Battery Voltage
Model Line for this Datasheet
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LT1512 SEPIC Constant-Current/ Constant-Voltage Battery Charger
FeaTures DescripTion
n
Charger Input Voltage May Be Higher, Equal to or
The LT®1512 is a 500kHz current mode switching regulator
Lower Than Battery Voltage
specially configured to create a constant-current/constant- n
Charges Any Number of Cells Up to 30V*
voltage battery charger. In addition to the usual voltage n
1% Voltage Accuracy for Rechargeable Lithium
feedback node, it has a current sense feedback circuit for
Batteries
accurately controlling output current of a flyback or SEPIC n
500kHz Switching Frequency Minimizes
(Single-Ended Primary Inductance Converter) topology
Inductor Size
charger. These topologies allow the current sense circuit n 100mV Current Sense Voltage for High Efficiency to be ground referred and completely separated from the n Battery Can Be Directly Grounded battery itself, simplifying battery switching and system n Charging Current Easily Programmable or Shut Down grounding problems. In addition, these topologies allow charging even when the input voltage is lower than the battery voltage.
applicaTions
Maximum switch current on the LT1512 is 1.5A. This allows n Battery Charging of NiCd, NiMH, Lead-Acid or battery charging currents up to 1A for a single lithium-ion Lithium Rechargeable Cells cell. Accuracy of 1% in constant-voltage mode is perfect n Precision Current Limited Power Supply for lithium battery applications. Charging current can be n Constant-Voltage/Constant-Current Supply easily programmed for all battery types. n Transducer Excitation L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. *Maximum Input Voltage = 40V – VBAT
Typical applicaTion Maximum Charging Current
WALL L1 A* 1.0 ADAPTER • C2** D1 INPUT + C3 2.2µF SINGLE MBRS130LT3 22µF V LITHIUM IN 25V VSW 0.5A 0.8 CELL (4.1V) CHARGE SYNC LT1512 L1 B* R1 AND/OR S/S 0.6 DOUBLE • SHUTDOWN FB LITHIUM SHUTDOWN GND GND S VC IFB + CELL (8.2V) R4 R2 C1 0.4 24Ω 22µF CURRENT (A) 6V BATTERY C5 25V 0.1µF 12V BATTERY R5 0.2 C4 R3 1k 0.22µF 0.2Ω INDUCTOR = 33µH 0 *L1 A, L1 B ARE TWO 33µH WINDINGS ON A 0 5 10 15 20 25 SINGLE INDUCTOR: COILTRONICS CTX33-3 INPUT VOLTAGE (V) **TOKIN CERAMIC 1E225ZY5U-C203-F 1512 F01 1512 TA02 ACTUAL PROGRAMMED CHARGING CURRENT wILL BE INDEPENDENT OF INPUT
Figure 1. SEPIC Charger with 0.5A Output Current
VOLTAGE AND BATTERy VOLTAGE IF IT DOES NOT ExCEED THE VALUES SHOwN. THESE ARE ELECTRICAL LIMITATIONS BASED ON MAxIMUM SwITCH CURRENT. PACKAGE THERMAL LIMITATIONS MAy REDUCE MAxIMUM CHARGING CURRENT. SEE APPLICATIONS INFORMATION. 1512fc For more information www.linear.com/LT1512 1 Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts
FeaTures DescripTion
n
Charger Input Voltage May Be Higher, Equal to or
The LT®1512 is a 500kHz current mode switching regulator
Lower Than Battery Voltage
specially configured to create a constant-current/constant- n
Charges Any Number of Cells Up to 30V*
voltage battery charger. In addition to the usual voltage n
1% Voltage Accuracy for Rechargeable Lithium
feedback node, it has a current sense feedback circuit for
Batteries
accurately controlling output current of a flyback or SEPIC n
500kHz Switching Frequency Minimizes
(Single-Ended Primary Inductance Converter) topology
Inductor Size
charger. These topologies allow the current sense circuit n 100mV Current Sense Voltage for High Efficiency to be ground referred and completely separated from the n Battery Can Be Directly Grounded battery itself, simplifying battery switching and system n Charging Current Easily Programmable or Shut Down grounding problems. In addition, these topologies allow charging even when the input voltage is lower than the battery voltage.
applicaTions
Maximum switch current on the LT1512 is 1.5A. This allows n Battery Charging of NiCd, NiMH, Lead-Acid or battery charging currents up to 1A for a single lithium-ion Lithium Rechargeable Cells cell. Accuracy of 1% in constant-voltage mode is perfect n Precision Current Limited Power Supply for lithium battery applications. Charging current can be n Constant-Voltage/Constant-Current Supply easily programmed for all battery types. n Transducer Excitation L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. *Maximum Input Voltage = 40V – VBAT
Typical applicaTion Maximum Charging Current
WALL L1 A* 1.0 ADAPTER • C2** D1 INPUT + C3 2.2µF SINGLE MBRS130LT3 22µF V LITHIUM IN 25V VSW 0.5A 0.8 CELL (4.1V) CHARGE SYNC LT1512 L1 B* R1 AND/OR S/S 0.6 DOUBLE • SHUTDOWN FB LITHIUM SHUTDOWN GND GND S VC IFB + CELL (8.2V) R4 R2 C1 0.4 24Ω 22µF CURRENT (A) 6V BATTERY C5 25V 0.1µF 12V BATTERY R5 0.2 C4 R3 1k 0.22µF 0.2Ω INDUCTOR = 33µH 0 *L1 A, L1 B ARE TWO 33µH WINDINGS ON A 0 5 10 15 20 25 SINGLE INDUCTOR: COILTRONICS CTX33-3 INPUT VOLTAGE (V) **TOKIN CERAMIC 1E225ZY5U-C203-F 1512 F01 1512 TA02 ACTUAL PROGRAMMED CHARGING CURRENT wILL BE INDEPENDENT OF INPUT
Figure 1. SEPIC Charger with 0.5A Output Current
VOLTAGE AND BATTERy VOLTAGE IF IT DOES NOT ExCEED THE VALUES SHOwN. THESE ARE ELECTRICAL LIMITATIONS BASED ON MAxIMUM SwITCH CURRENT. PACKAGE THERMAL LIMITATIONS MAy REDUCE MAxIMUM CHARGING CURRENT. SEE APPLICATIONS INFORMATION. 1512fc For more information www.linear.com/LT1512 1 Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts
