NXP Semiconductors MC34674CEPR2

Overview

MC34674CEPR2 from Freescale Semiconductor is a fully integrated single-cell Li-Ion/Li-Polymer battery charger optimized for travel charger applications. It delivers 650 mA constant-current charge current with ±0.4% output voltage accuracy at 4.2 V, supports up to 28 V input voltage, and integrates NTC thermistor interface, dual-color LED status indication, and smart battery connection verification. It operates in trickle/CC/CV modes and features internal thermal foldback and input over-voltage protection (11 V threshold).

For engineers reviewing the MC34674CEPR2 datasheet, MC34674CEPR2 pinout, MC34674CEPR2 application, or MC34674CEPR2 equivalent, key selection considerations include its factory-programmed 650 mA CC current, UDFN-8 (2×3 mm²) thermally enhanced package, 8-pin functional pinout with open-drain GRN/RED indicators, and compatibility with current-limited AC/DC adapters via 2.6 V falling POR threshold.

Technical Context

The MC34674CEPR2 implements a dedicated analog charge controller architecture with integrated power MOSFET, VIN-BAT comparator (with 22–60 mV offset), and precision bandgap reference. Its charge algorithm strictly follows JEITA-compliant trickle → constant-current → constant-voltage sequencing, with EOC detection based on 65 mA threshold (10% of 650 mA ICHG) sustained for ≥500 ms.

Thermal regulation activates at 110°C die temperature, reducing charge current via internal foldback; temperature window control is implemented through a ratiometric NTC interface using VREF (1.22 V typical) as bias source, with low/high thresholds defined as fractions (1/3 and 2/3) of VREF. Input over-voltage protection triggers at 11 V (typ.) with 400 mV hysteresis.

Key Specifications

Pinout & Package

MC34674CEPR2 is housed in an 8-lead, 2 mm × 3 mm, 0.5 mm pitch UDFN-EP package with exposed thermal pad (EPAD). The EPAD must be electrically connected to GND and soldered to a large PCB ground plane for effective thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Li-ion linear charger applications.

Compared with MC34674CEPR2, TPS65023BRSBR adds system power rails but increases component count and layout complexity, while BQ24075RGTR offers lower integration for thermal safety and status indication-making MC34674CEPR2 optimal for compact, self-contained travel chargers requiring JEITA compliance out-of-the-box.

Availability

MC34674CEPR2 is available at Aetrix Electronics and suitable for portable medical devices, USB-C travel adapters, industrial handheld terminals, and smart power banks requiring stable component supply, long lifecycle support, and automotive-grade reliability in commercial temperature range (–40°C to +85°C).

Supply support for MC34674CEPR2 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

Freescale Semiconductor (now part of NXP Semiconductors) is a global leader in analog and mixed-signal ICs for power management, automotive, and industrial applications.

The MC34674CEPR2 belongs to Freescale's high-voltage linear battery charger product line, designed specifically for cost-sensitive, space-constrained travel and cradle charger applications requiring robust thermal and over-voltage protection without external discrete components.

FAQ

What is the factory-programmed charge current for MC34674CEPR2?

The MC34674CEPR2 is factory-programmed for a constant-current (CC) charge current of 650 mA, with ±8% tolerance. This value is fixed and cannot be adjusted externally-it is set during manufacturing per Table 1 of the datasheet and corresponds to the "C" variant in the MC34674 family. The IC automatically enters trickle, CC, and CV modes using this preset current.

Does MC34674CEPR2 require external MOSFETs or current-sense resistors?

No, MC34674CEPR2 does not require external MOSFETs or current-sense resistors. It integrates a power MOSFET with maximum RDS(ON) of 450 mΩ and implements current regulation entirely internally. All charge control-including trickle, CC, and CV modes-is managed on-die, reducing BOM count and PCB footprint significantly compared to discrete charger solutions.

How does MC34674CEPR2 implement battery temperature monitoring?

MC34674CEPR2 implements battery temperature monitoring via its dedicated NTC interface: TEMP pin reads voltage from an external NTC thermistor divider biased by the VREF pin (1.22 V typical). Thresholds are ratiometric-low-temp fault triggers when TEMP > 2/3 × VREF, high-temp fault when TEMP < 1/3 × VREF-enabling precise, supply-independent temperature windowing without external ADCs or comparators.

What is the purpose of the GRN and RED pins on MC34674CEPR2?

The GRN and RED pins on MC34674CEPR2 are open-drain LED drivers, each capable of sinking up to 6 mA. GRN indicates charge completion or recharge mode (active-low); RED indicates active charging (trickle or CC/CV). When both are active, they produce yellow illumination for fault conditions (OVP, thermal, NTC, TIMEOUT). No external current-limiting resistors are needed due to internal current regulation.

Can MC34674CEPR2 operate with a current-limited AC/DC adapter?

Yes, MC34674CEPR2 is explicitly designed for use with current-limited AC/DC adapters. Its 2.6 V falling power-on-reset (POR) threshold ensures reliable startup even when input voltage sags under load. Combined with 28 V max input rating and 11 V over-voltage protection, it maintains safe, stable operation across low-cost, unregulated adapter outputs without requiring additional input conditioning circuitry.