The LTC1734L is a low cost, single cell, constant-current/constant-voltage Li-Ion battery charger controller. When combined with a few external components, the SOT-23 package forms a very small, low cost charger for single cell lithium-ion batteries. The LTC1734L is a lower charge current version of the LTC1734.The LTC1734L provides a fixed float voltage of 4.2V with 1% accuracy (for 4.1V and 4.15V float voltages, contact Analog Devices Marketing). Constant current is programmed using a single external resistor between the PROG pin and ground. Manual shutdown is accomplished by floating the program resistor while removing input power automatically puts the LTC1734L into a sleep mode. Both the shutdown and sleep modes drain near zero current from the battery.Charge current can be monitored via the voltage on the PROG pin allowing a microcontroller or ADC to read the current and determine when to terminate the charge cycle. The output driver is both current limited and thermally protected to prevent the LTC1734L from operating outside of safe limits. No external blocking diode is required.The LTC1734L can also function as a general purpose current source or as a current source for charging nickel-cadmium (NiCd) and nickel-metal-hydride (NiMH) batteries using external termination. Charge Current V float LTC1734 180mA to 700mA 4.1V or 4.2V LTC1734L 50mA to 180mA 4.2V Applications Cellular Telephones Handheld Computers Digital Cameras Charging Docks and Cradles Low Cost and Small Size Chargers Programmable Current Sources

The low-cost MAX1873R/S/T provides all functions needed to simply and efficiently charge 2-, 3-, or 4-series lithium-ion cells at up to 4A or more. It provides a regulated charging current and voltage with less than ±0.75% total voltage error at the battery terminals. An external P-channel MOSFET operates in a step-down DC-DC configuration to efficiently charge batteries in low-cost designs.The MAX1873R/S/T regulates the battery voltage and charging current using two control loops that work together to transition smoothly between voltage and current regulation. An additional control loop limits current drawn from the input source so that AC adapter size and cost can be minimized. An analog voltage output proportional to charging current is also supplied so that an ADC or microcontroller can monitor charging current.The MAX1873 may also be used as an efficient current-limited source to charge NiCd or NiMH batteries in multichemistry charger designs. The MAX1873R/S/T is available in a space-saving 16-pin QSOP package. Use the evaluation kit (MAX1873EVKIT) to help reduce design time.Applications2-, 3-, or 4-Cell Li+ Battery Pack Chargers6-, 9-, or 10-Cell Li+ Battery Pack ChargersDesktop Cradle ChargersHandheld Instruments (PDAs, Palmtops)Notebook ComputersPortable Desktop Assistants (PDAs)Portable Internet Tablets

With switching frequency as high as 500kHz, The LT1510 current mode PWM battery charger is the smallest, simplest, most efficient solution to fast-charge modern rechargeable batteries including lithium-ion (Li-Ion), nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd) that require constant-current and/or constant-voltage charging. The internal switch is capable of delivering 1.5A DC current (2A peak current). The 0.1Ω onboard current sense resistor makes the charging current programming very simple. One resistor (or a programming current from a DAC) is required to set the full charging current (1.5A) to within 5% accuracy. The LT1510 with 0.5% reference voltage accuracy meets the critical constant-voltage charging requirement for lithium cells. The LT1510 can charge batteries ranging from 2V to 20V. Ground sensing of current is not required and the battery’s negative terminal can be tied directly to ground. A saturating switch running at 200kHz (500kHz for LT1510-5) gives high charging efficiency and small inductor size. A blocking diode is not required between the chip and the battery because the chip goes into sleep mode and drains only 3µA when the wall adaptor is unplugged. Soft start and shutdown features are also provided. The LT1510 is available in a 16-pin fused lead power SO package with a thermal resistance of 50°C/W, an 8-pin SO and a 16-pin PDIP. Applications Chargers for NiCd, NiMH and Lithium Batteries Step-Down Switching Regulator with Precision Adjustable Current Limit

The MAX1259 battery manager provides backup-batteryswitching for CMOS RAM, microprocessors, or otherlow-power logic ICs. It automatically switches to thebackup battery when the primary power supply is interrupted.Low-loss switches guarantee an input-to-outputdifferential of only 200mV while supplying 250mA fromthe primary power supply or 15mA from the battery.Battery discharge during shipping does not occur in theMAX1259, since the backup battery can be disconnectedby strobing the RST input.A battery-fail output signal indicates when the backupbattery is below +2V, and a power-fail output signal indicateswhen the primary power supply is low. TheMAX1259 monitors the backup battery, warns ofimpending power failures, and switches the memory tothe battery when failures occur. The MAX1259 is pin-compatiblewith the DS1259, but consumes three timesless supply current. Commercial, extended, and militarytemperature range devices are available.ApplicationsBattery Backup for CMOS RAMComputersControllersUninterruptible Power Supplies

Battery Management

Battery Management Const-V/Const-C Bat Chr

Battery Management USB Compatible Sw Pwr Manager/LiFePO4 Ch

Consumer Battery & Photo Battery 3V Li 750Mah

Battery Management USB Pwr Manager w/ Hi V Sw Chr

Coin Cell Battery 3V 48mAh, 2 Pin Flat Mount