Analog Devices Inc. LTC4061EDD-4.4#PBF

Overview

LTC4061EDD-4.4 from Analog Devices (formerly Linear Technology) is a standalone linear Li-ion battery charger IC designed for single-cell 4.375V batteries, featuring ±0.4% float voltage accuracy, programmable up to 800mA charge current via external resistor, thermistor-based temperature qualification, and integrated thermal regulation. It operates directly from USB 4.5–8V input and supports C/5 current limiting for USB compliance.

For engineers reviewing the LTC4061EDD-4.4 datasheet, LTC4061EDD-4.4 pinout, LTC4061EDD-4.4 application, or LTC4061EDD-4.4 equivalent, key selection considerations include its 10-lead DFN package with exposed pad, dual termination modes (timer- or current-based), SmartStart algorithm for battery life extension, NTC interface logic thresholds, and shutdown quiescent current of 20µA.

Technical Context

The LTC4061EDD-4.4 implements a constant-current/constant-voltage (CC/CV) charging algorithm with internal P-channel MOSFET (RON = 375mΩ), eliminating need for external blocking diode or sense resistor. Its thermal regulation loop maintains die temperature at ~105°C by dynamically reducing charge current under high ambient or power conditions.

Termination is configurable via TIMER pin: capacitor-to-ground enables 3-hour time-based termination (CTIMER = 0.1µF), ground enables current-based termination using IDET pin threshold (e.g., 100mA with RDET = 1kΩ), and VCC enables user-controlled termination. CHRG and ACPR are open-drain status outputs with defined low-voltage specs (≤0.25V @ 5mA).

Key Specifications

Pinout & Package

Package: 10-lead (3mm × 3mm) DFN with 0.75mm profile and exposed thermal pad (Pin 11 = GND, must be soldered to PCB for θJA = 40°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar standalone Li-ion charging applications.

Compared with MAX1555ETA+ and BQ24075RGTR, the LTC4061EDD-4.4 uniquely balances analog simplicity (no I2C), precision (±0.4% VFLOAT), and autonomous safety (NTC, SmartStart, thermal foldback) in a 3×3mm DFN - ideal for space-constrained, MCU-less USB-charged devices.

Availability

LTC4061EDD-4.4 is available at Aetrix Electronics and suitable for USB-powered portable audio, medical wearables, industrial handheld terminals, and IoT asset trackers requiring stable component supply and long-term manufacturability.

Supply support for LTC4061EDD-4.4 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 semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC4061EDD-4.4 belongs to Linear's legacy standalone battery charger family, engineered for simplicity, reliability, and minimal external components in cost-sensitive, space-constrained portable electronics.

FAQ

What is the exact float voltage and accuracy of the LTC4061EDD-4.4?

The LTC4061EDD-4.4 regulates battery voltage to a precise 4.375V with ±0.4% accuracy over –40°C to 85°C. This specification is guaranteed by design and confirmed in the Electrical Characteristics table (VFLOAT = 4.358V to 4.392V at TA = 25°C; 4.35V to 4.4V over full range). The LTC4061EDD-4.4 achieves this using an internal bandgap reference and trimmed feedback network - critical for maximizing Li-ion cycle life and capacity retention.

How is charge current programmed on the LTC4061EDD-4.4?

Charge current is set by connecting a resistor (RPROG) from the PROG pin (Pin 9) to ground. In constant-current mode, the PROG pin holds at 1.0V, so ICHG = 1000 × (1.0V / RPROG). For example, RPROG = 1.25kΩ yields 800mA. The LTC4061EDD-4.4 also allows real-time current monitoring via the same PROG pin voltage - no external sense resistor is needed due to its integrated PMOS architecture.

Does the LTC4061EDD-4.4 support USB-compliant current limiting?

Yes, the LTC4061EDD-4.4 supports USB current limiting via the C/5 pin (Pin 6). When pulled high, it delivers 100% of the PROG-programmed current; when low (or left floating, due to internal 3MΩ pull-down), it limits current to 20% - enabling strict compliance with USB 100mA (low-power) and 500mA (high-power) port specifications. This feature is integral to the LTC4061EDD-4.4's USB-native design.

What happens during thermal overload, and how does the LTC4061EDD-4.4 respond?

When the LTC4061EDD-4.4 die temperature approaches ~105°C, its internal thermal regulation loop automatically reduces charge current to maintain safe junction temperature. This foldback behavior prevents overheating without shutting down - allowing continuous charging under worst-case ambient or PCB layout conditions. The LTC4061EDD-4.4 specifies RON = 375mΩ and θJA = 40°C/W (with exposed pad soldered), making thermal performance predictable and designable.

Can the LTC4061EDD-4.4 automatically restart charging after partial discharge?

Yes, the LTC4061EDD-4.4 implements automatic recharge: when in standby mode and BAT voltage drops below 4.275V (≈85% SOC), it restarts a full charge cycle and resets the internal timer to 50% of the programmed duration. This SmartStart feature is enabled by default and eliminates manual intervention - a core capability of the LTC4061EDD-4.4 that directly extends usable battery life in cyclic-use applications.