
Philips Electronics
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.