DESCRIPTION

The 74LV4799 is a low-voltage Si-gate CMOS control IC for battery management. It consists of:

? 17-stage divider

? 10-stage up/down counter

? Control logic

? Integrated precision oscillator (using external timing components)

? Automatic power-ON reset

? Scan test facilities

? Battery charging/full indication output (LED)

? Battery-low indication output (MOLLI)

? Open-drain-N outputs for driving the load transistor

FEATURES

? Wide supply voltage range of 0.9 V to 6 V allows 1 to 4-cell

applications

? 10 V allowed on special inputs

? Supports virtually all battery chargers, including switched-mode

power supplies

? On-chip timer calculates the actual capacity of the battery by

measuring the charger time, discharge time and self-discharge time

? Automatic switch-over to trickle charge after completion of the

charge time

? Can be adjusted for use with different types of batteries:

– Charge time: 4 to 16 hours

– Discharge time: 15 minutes to 4.7 hours

– Self-discharge time: 50 to 100 days

? Battery status indication included:

– LED output for charging/full indication

– MOLLI output for battery-low indication

? LED mode select allows two different methods of indication

? Automatic power-ON reset

? Low-power consumption

? Requires only a few peripheral components

? Very accurate on-chip oscillator

? Scan test facilities included

? ICC category: non-standard.

APPLICATIONS

? Time-controlled NiCd and NiMH low-current chargers

? Domestic appliances such as rechargeable battery shavers,

electric toothbrushes etc.

? Portable equipment such as notebook PCs, laptop PCs, camera

flash units etc.

? Personal communications like cordless telephones, personal

mobile radios, pagers, etc.