LTC4121LTC4121-4.2 Series

40V 400mA Synchronous Step-Down Battery Charger

Manufacturer: Analog Devices Inc./Maxim Integrated

Catalog

40V 400mA Synchronous Step-Down Battery Charger

Part	Charge Current - Max [Max]	Battery Chemistry [custom]	Battery Pack Voltage	Voltage - Supply (Max) [Max]	Operating Temperature [Min]	Operating Temperature [Max]	Package / Case	Supplier Device Package	Mounting Type	Current - Charging	Battery Pack Voltage [Max]	Battery Chemistry
Analog Devices Inc./Maxim Integrated LTC4121IUD-4.2#PBF	400 mA	Lithium Ion/Polymer	4.2 V	40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable
Analog Devices Inc./Maxim Integrated LTC4121EUD-4.2#PBF	400 mA	Lithium Ion/Polymer	4.2 V	40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable
Analog Devices Inc./Maxim Integrated LTC4121IUD-4.2#TRPBF	400 mA	Lithium Ion/Polymer	4.2 V	40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable
Analog Devices Inc./Maxim Integrated LTC4121IUD#PBF	400 mA			40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable	18 V	Multi-Chemistry
Analog Devices Inc./Maxim Integrated LTC4121EUD#PBF	400 mA			40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable	18 V	Multi-Chemistry
Analog Devices Inc./Maxim Integrated LTC4121IUD#TRPBF	400 mA			40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable	18 V	Multi-Chemistry
Analog Devices Inc./Maxim Integrated LTC4121EUD#TRPBF	400 mA			40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable	18 V	Multi-Chemistry
Analog Devices Inc./Maxim Integrated LTC4121EUD-4.2#TRPBF	400 mA	Lithium Ion/Polymer	4.2 V	40 V	-40 C	125 °C	16-WFQFN Exposed Pad	16-QFN (3x3)	Surface Mount	Constant - Programmable

Catalog

40V 400mA Synchronous Step-Down Battery Charger

Description

The LTC4121 is a 400mA constant-current/constantvoltage (CC/CV) synchronous step-down battery charger. In addition to CC/CV operation, the LTC4121 regulates its input voltage to a programmable percentage of the input open-circuit voltage. This technique maintains maximum power transfer with high impedance input sources such as solar panels.An external resistor programs the charge current up to 400mA. The LTC4121-4.2 is suitable for charging Li-Ion/ Polymer batteries, while the programmable float voltage of the LTC4121 is suitable for several battery chemistries.The LTC4121 and LTC4121-4.2 include an accurate RUN pin threshold, low voltage battery preconditioning and bad battery fault detection, timer termination, auto-recharge, and NTC temperature qualified charging. TheFAULTpin provides an indication of bad battery or temperature faults.Once charging is terminated, the LTC4121 signals end-ofcharge via theCHRGpin, and enters a low current SLEEP mode. An auto-restart feature starts a new charging cycle if the battery voltage drops by 2.2%.ApplicationsHandheld InstrumentsSolar Powered DevicesIndustrial/Military Sensors and Devices