Analog Devices Inc. LTC4012CUF-2#PBF

Overview

LTC4012CUF-2#PBF from Analog Devices (formerly Linear Technology) is a synchronous buck battery charger controller optimized for 4.2V/cell Li-ion/polymer packs (2–4 series cells). It delivers ±0.5% float voltage accuracy, programmable charge current with 4% accuracy, and 550kHz quasi-constant-frequency PWM operation-enabling high-efficiency, low-noise charging in notebook computers and portable instruments.

For engineers reviewing the LTC4012CUF-2#PBF datasheet, LTC4012CUF-2#PBF pinout, LTC4012CUF-2#PBF application, or LTC4012CUF-2#PBF equivalent, key selection considerations include its pin-programmable 4.2V/cell output, INFET-based PowerPath™ ideal diode control, AC adapter input current limiting with ICL status indication, and 20-pin 4mm × 4mm QFN package with exposed thermal pad.

Technical Context

The LTC4012CUF-2#PBF implements current-mode PWM control with internal 1.2085V reference and synchronous rectification via BGATE/TGATE drivers. Its FVS0/FVS1 pins are hardwired to select 4.2V/cell output-distinct from the adjustable LTC4012 or 4.1V/cell LTC4012-1 variant-enabling direct configuration without external resistor dividers.

PowerPath™ control uses INFET to drive an external PMOS between DCIN and CLP, regulating forward drop to ~25mV and blocking reverse current within 6µs when DCIN falls below CLP by >25mV. Input current limiting is set by R_IN across CLP/CLN, with ±3% accuracy and active ICL status flag.

Key Specifications

Pinout & Package

20-pin 4mm × 4mm plastic QFN (UF package) with exposed thermal pad (Pin 21 = GND), requiring soldering to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4012CUF-1#PBF, the LTC4012CUF-2#PBF provides higher per-cell termination voltage for modern high-capacity Li-ion, while versus BQ24725ARHRT it eliminates I²C dependency and reduces external component count for cost-sensitive, analog-controlled designs.

Availability

LTC4012CUF-2#PBF is available at Aetrix Electronics and suitable for notebook computers, portable instruments, and battery backup systems requiring stable component supply, long-term manufacturability, and automotive-grade reliability validation.

Supply support for LTC4012CUF-2#PBF 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

Analog Devices (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management ICs, serving industrial, automotive, communications, and medical markets.

The LTC4012 family was designed as a flexible, high-accuracy battery charger controller platform for multi-cell Li-ion/polymer applications-emphasizing precision voltage regulation, low-noise operation, and robust PowerPath™ management without built-in termination logic.

FAQ

What battery chemistries does the LTC4012CUF-2#PBF support?

The LTC4012CUF-2#PBF supports Li-ion and Li-polymer batteries configured in 2-, 3-, or 4-series cell packs with fixed 4.2V/cell output. It does not include built-in charge termination logic, so external microcontroller supervision is required for full CC/CV cycling, temperature cutoff, or timer-based end-of-charge detection. The LTC4012CUF-2#PBF itself operates independently of chemistry-specific algorithms.

How is the 4.2V/cell output configured on the LTC4012CUF-2#PBF?

The LTC4012CUF-2#PBF uses factory-configured FVS0 and FVS1 pins to fix the output voltage at 4.2V/cell - FVS0 is internally grounded and FVS1 is pulled to INTVDD. No external resistors or configuration pins are needed. This differs from the adjustable LTC4012 (requires VFB/FBDIV divider) and the 4.1V/cell LTC4012CUF-1#PBF (opposite FVS logic).

Does the LTC4012CUF-2#PBF include PowerPath™ control, and how does it work?

Yes, the LTC4012CUF-2#PBF integrates PowerPath™ control via the INFET pin, which drives an external PMOS transistor between DCIN and CLP. It regulates forward voltage to ~25mV during charging and blocks reverse current in <6µs if DCIN drops below CLP by >25mV. This enables automatic switchover between adapter and battery without external circuitry.

What is the purpose of the PROG pin on the LTC4012CUF-2#PBF?

The PROG pin on the LTC4012CUF-2#PBF serves dual functions: (1) it programs maximum charge current via an external resistor to GND, and (2) it outputs a voltage linearly proportional to actual charge current (11.67µA/mV). This enables both precise current setting and real-time analog monitoring without additional sensors or signal conditioning.

Can the LTC4012CUF-2#PBF operate without an external microcontroller?

The LTC4012CUF-2#PBF can perform constant-current/constant-voltage charging autonomously once configured, but it lacks built-in charge termination, temperature monitoring, or safety timers. For safe, compliant Li-ion charging, an external microcontroller is required to interpret CHRG/ICL/ACP status pins and manage full charge algorithms - the LTC4012CUF-2#PBF acts as the precision power stage controller.