BATTERY CHARGER, LI-ION/LIFEPO4, 125DEGC

BATTERY CHARGERS ROHS COMPLIANT: YES

BATTERY FUEL GAUGES ROHS COMPLIANT: YES

BATTERY CHARGERS ROHS COMPLIANT: YES

BATTERY CHARGERS ROHS COMPLIANT: YES

BATTERY CHARGERS ROHS COMPLIANT: YES

BATTERY CHARGERS ROHS COMPLIANT: YES

BATTERY CHARGERS ROHS COMPLIANT: YES

The MAX745 provides all functions necessary for charging lithium-ion (Li+) battery packs. It provides a regulated charging current of up to 4A without getting hot, and a regulated voltage with only ±0.75% total error at the battery terminals. It uses low-cost, 1% resistors to set the output voltage, and a low-cost N-channel MOSFET as the power switch.The MAX745 regulates the voltage set point and charging current using two loops that work together to transition smoothly between voltage and current regulation. The per-cell battery voltage regulation limit is set between 4V and 4.4V using standard 1% resistors, and then the number of cells is set from 1 to 4 by pin-strapping. Total output voltage error is less than ±0.75%.For a similar device with an SMBus™ microcontroller interface and the ability to charge NiCd and NiMH cells, refer to the MAX1647 and MAX1648. For a low-cost Li+ charger using a linear-regulator control scheme, refer to the MAX846A.ApplicationsCell PhonesDesktop Cradle ChargersHandheld Instruments (PDAs, Palmtops)Li+ Battery PacksNotebook Computers

The MAX846A is a cost-saving multichemistry battery-charger system that comes in a space-saving 16-pin QSOP. This integrated system allows different battery chemistries (Li-Ion, NiMH or NiCd cells) to be charged using one circuit.In its simplest application, the MAX846A is a stand-alone, current-limited float voltage source that charges Li-Ion cells. It can also be paired up with a low-cost microcontroller (µC) to build a universal charger capable of charging Li-Ion, NiMH, and NiCd cells.An internal 0.5%-accurate reference allows safe charging of Li-Ion cells that require tight voltage accuracy. The voltage- and current-regulation loops used to control a low-cost external PNP transistor (or P-channel MOSFET) are independent of each other, allowing more flexibility in the charging algorithms.The MAX846A has a built-in 1%, 3.3V, 20mA linear regulator capable of powering the µC and providing a reference for the µC's analog-to-digital converters. An on-board reset notifies the controller upon any unexpected loss of power. The µC can be inexpensive, since its only functions are to monitor the voltage and current and to change the charging algorithms.ApplicationsCell PhonesDesktop Cradle ChargersHandheld Instruments (PDAs, Palmtops)Li+ Battery PacksLi+-Ion/NiMH/NiCd Multichemistry Battery ChargersNotebook Computers