74LV4799D,118

Overview

The 74LV4799 is a low-voltage Si-gate CMOS control IC designed for battery management in NiCd and NiMH chargers. It operates on a supply voltage range of 0.9 V to 6.0 V, supporting 1 to 4-cell applications. The device integrates a 17-stage divider, a 10-stage up/down counter, control logic, and an accurate on-chip oscillator. Key features include automatic power-on reset, scan test facilities, and outputs for charging/full indication (LED) and battery-low status (MOLLI). It measures charge, discharge, and self-discharge times to calculate actual battery capacity.

Feature Summary

• Wide supply voltage range of 0.9 V to 6.0 V allows operation with 1 to 4-cell batteries.
• On-chip timer calculates battery capacity by measuring charge, discharge, and self-discharge times.
• Automatic switch-over to trickle charge mode upon completion of the charge cycle.
• Includes LED output for charging/full indication and MOLLI output for battery-low status.
• Supports various battery types with adjustable charge time (4-16 hours), discharge time (15 min-4.7 hours), and self-discharge time (50-100 days).

Applications

• Time-controlled NiCd and NiMH low-current chargers
• Domestic appliances such as rechargeable battery shavers and electric toothbrushes
• Portable equipment including notebook PCs, laptop PCs, and camera flash units
• Personal communications devices like cordless telephones and pagers

Procurement Notes

Verify the specific package variant required, as the base part number covers multiple packages including 16-Pin Plastic DIL, SO, SSOP Type II, and TSSOP Type I. Confirm temperature range specifications, as standard versions operate from 0°C to +70°C. Ensure compatibility with existing timing components, as oscillator frequency depends on external resistors and capacitors connected to RC, RD, and RS pins.

Selection Notes

Select based on the required operating temperature range and physical package constraints. The device supports input voltages up to 10 V on specific pins (Vin, PWRS, DIS), which is beneficial for motor-driven charger applications. Consider the LED mode select (SEL) pin configuration to determine the desired blinking frequency behavior for charge and trickle modes. Verify that external component values fall within the recommended ranges to maintain timing accuracy.

Part Context

The 74LV4799 belongs to the 74LV series of low-voltage CMOS logic devices. It is specifically engineered for battery charging management rather than general-purpose logic functions. The device replaces older technologies by offering precise timing capabilities with minimal peripheral components. It is suitable for applications requiring reliable charge termination and battery health monitoring in portable electronics.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.