MILPITAS, CA - July 28, 2010 - Linear Technology Corporation introduces the LTC4098-3.6,an autonomous high efficiency power manager, ideal diode controller and battery charger for1-cell Lithium Iron Phosphate (LiFePO4) batteries used in portable devices such as industrialmeters, media players, digital cameras, PDAs, personal navigators, and especially highpeak-power and safety critical equipment. The LTC4098-3.6's switching topology featuresPowerPathTM control, which seamlessly manages power distribution from multiple sources,including 5V wall adapter, USB and a LiFePO4 battery, while preferentially providing powerto the system load.
For automotive and other high voltage applications, the LTC4098-3.6 caninterface with a Linear Technology external switching regulator to provide a high efficiencyhigh voltage power path. The onboard switching regulator can automatically limit its inputcurrent for USB compatibility. Both the low voltage input and the high voltage interface featureBat-TrackTM optimized charging to provide maximum power to the application and reduced heatin high power density applications with input supplies from 5V to as high as 38V (60V absolutemaximum).
The LTC4098-3.6 provides an overvoltage protection (OVP) circuit up to 66V on thelow voltage input, requiring only an external NFET/resistor combination thereby preventingdamage caused by accidental application of high voltage. The LTC4098-3.6's "instant-on"operation ensures system load power at plug-in, even with a fully discharged battery.
Its onboardideal diode guarantees that ample power is always available to VOUT even if there is insufficientpower at the input. The LTC4098-3.6's ideal diode controller can be used to drive the gate of anoptional PFET, reducing impedance to the battery to 30mOhm or less.The LTC4098-3.6's full-featured single-cell LiFePO4 battery charger has a preset 3.6Vcharge voltage with high accuracy of 0.5%. Charge current of 1.5A is available when wallUSB Compatible High Efficiency Power Manager &page 2Charger for 1-Cell Lithium Iron Phosphate Batteriespowered, but when connected to a USB power supply, the device allows the load current toexceed the current drawn from the USB port, while conforming to USB load specifications.
Forfast charging, the IC's switching input stage converts nearly all of the 2.5W available from USBto system current, enabling up to 700mA from a 500mA limited USB port. Further, the chargerincludes thermal limiting, automatic recharge, stand-alone operation with automatic chargetermination and fixed 1-hour safety timer, bad battery cell detection and a thermistor input for0°C to 60°C temperature-qualified charging. An additional feature of the IC is a suspend LDOthat helps to prevent battery drain when a device is connected to a suspended USB port.
