NXP Semiconductors 74LV4799PW,112

Overview

74LV4799PW,112 from NXP Semiconductors (formerly Philips) is a low-voltage CMOS battery management IC designed specifically for NiCd/NiMH charger control. It integrates a 17-stage divider, 10-stage up/down counter, precision oscillator with external RC timing, automatic power-on reset, and dual enable outputs (EN/EN) for driving external PNP/NPN transistor pairs. Key confirmed parameters include 0.9–6.0 V supply range, ±7% oscillator frequency tolerance, 36 µA typical operating current at 3.3 V, 4–16 hour programmable charge time, and 50–100 day self-discharge timing window - deployed in cordless telephones and electric toothbrushes.

For engineers reviewing the 74LV4799PW,112 datasheet, 74LV4799PW,112 pinout, 74LV4799PW,112 application, or 74LV4799PW,112 equivalent, this page delivers verified functional architecture, exact timing parameter mapping (RC/RD/RS oscillator paths), battery status signaling logic (LED/MOLLI), charge/discharge/self-discharge mode transitions, and real-world peripheral interface requirements - all validated against the 1998 Philips IC24 Data Handbook specification.

Technical Context

The 74LV4799PW,112 implements time-based battery management via a synchronous 17-stage divider and 10-stage up/down counter driven by an on-chip oscillator whose frequency is set by external RC, RD, and RS networks tied to dedicated 3-state outputs. Its control logic interprets PWRS (power sense, 0–100 kHz AC/DC), DIS (discharge enable, active LOW), and SEL (LED mode select) to determine operating mode - charge, trickle charge, discharge, charge/discharge, or self-discharge - each with distinct counter direction and timing constants.

It features dual open-drain enable outputs (EN active HIGH, EN active LOW) for direct drive of bipolar transistor pairs controlling battery charging current, plus MOLLI/SCO (active LOW low-battery alarm with 4×1s pulse output) and LED driver (blink-mode configurable via SEL). Power-on reset is bistable and synchronized to the internal clock, ensuring reliable initialization even below 0.9 V.

Key Specifications

Pinout & Package

74LV4799PW,112 is housed in a 16-pin TSSOP Type I package (SOT403-1), 4.4 mm × 2.5 mm × 1.1 mm body, 0.65 mm pitch, lead-free compatible.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery timer applications.

Compared with MAX713 and UC3906, the 74LV4799PW,112 uniquely combines fully programmable multi-phase timing, ultra-low 36 µA standby current, integrated scan-test diagnostics, and dual-enable bipolar drive - making it the only option supporting certified NiMH maintenance cycles and remaining-energy readout in space-constrained consumer chargers.

Availability

74LV4799PW,112 is available at Aetrix Electronics and suitable for cordless telephone bases, electric toothbrush docks, rechargeable shaver adapters, and notebook PC backup battery maintainers requiring stable component supply across extended production lifecycles.

Supply support for 74LV4799PW,112 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors, originally Philips Semiconductors, is a global leader in high-reliability analog and mixed-signal ICs for power management and battery systems, with deep heritage in consumer electronics timing solutions.

The 74LV4799PW,112 belongs to NXP's legacy LV logic and battery management product line, engineered specifically for cost-sensitive, low-power NiCd/NiMH charger applications where precise time-based termination and minimal external component count are critical design constraints.

FAQ

What is the function of the RC, RD, and RS pins on the 74LV4799PW,112?

The RC, RD, and RS pins on the 74LV4799PW,112 are dedicated 3-state oscillator outputs that source current into external RC timing networks. RC sets the charge-time oscillator frequency (fC = 0.36/(RC × C1)), RD sets the discharge-time frequency (fD = 0.36/(RD × C1)), and RS sets the self-discharge-time frequency (fS = 0.36/(RS × C1)). Each path operates independently, enabling precise, decoupled adjustment of all three battery management phases without component interaction or calibration drift.

How does the 74LV4799PW,112 handle low-voltage startup with a deeply discharged battery?

The 74LV4799PW,112 handles low-voltage startup via its Vin pin (pin 4), which provides bias current to external bipolar transistors even before internal logic becomes operational. This allows initial charging current to flow while VCC rises. Simultaneously, its bistable power-on reset synchronizes to the internal clock, guaranteeing deterministic counter initialization below 0.9 V - a feature validated in motor-loaded environments where supply dips occur during switch-on.

Can the 74LV4799PW,112 be used for lithium-ion battery charging?

No, the 74LV4799PW,112 is not suitable for lithium-ion battery charging. Its architecture is explicitly designed for NiCd/NiMH chemistries, relying on fixed time-based termination and trickle charge compensation - methods incompatible with Li-ion's strict voltage- and temperature-dependent charging profiles. Using the 74LV4799PW,112 with Li-ion cells risks overvoltage, thermal runaway, or permanent capacity loss due to absence of CC/CV regulation or cell voltage monitoring.

What is the purpose of the SCAN and SCI pins on the 74LV4799PW,112?

The SCAN (pin 14) and SCI (pin 15) pins enable IEEE 1149.1-compatible serial scan testing of the 74LV4799PW,112's internal divider and counter logic. When SCAN is HIGH, the on-chip oscillator is bypassed, and test patterns are shifted in via SCI. The MOLLI/SCO pin (pin 6) then functions as serial scan-out, allowing full counter state readback - a capability repurposed for remaining battery energy estimation by reading the 10-bit counter value during brief test-mode interruptions.

How does the MOLLI output indicate low battery condition on the 74LV4799PW,112?

The MOLLI output (pin 6) on the 74LV4799PW,112 signals low battery condition by generating four precisely timed 1-second pulses (50% duty cycle) when the DIS input transitions from LOW to HIGH after the counter reaches zero in discharge mode. This pulse train activates external buzzers or LEDs. Crucially, the MOLLI function is interrupted immediately if PWRS becomes active - preventing false alarms during simultaneous charge/discharge operation.