Analog Devices Inc. LTC4061EDD#PBF

Overview

LTC4061EDD#PBF from Analog Devices (formerly Linear Technology) is a standalone linear Li-ion battery charger IC for single-cell 4.2V batteries, featuring ±0.35% float voltage accuracy, programmable charge current up to 1A via external resistor, NTC thermistor input for temperature-qualified charging, and thermal regulation at 105°C. It operates directly from USB power (4.3V–8V) and supports C/5 current limiting for USB compliance in portable electronics.

For engineers reviewing the LTC4061EDD#PBF datasheet, LTC4061EDD#PBF pinout, LTC4061EDD#PBF application, or LTC4061EDD#PBF equivalent, key selection considerations include its 10-lead DFN package with exposed pad, dual termination modes (time- or current-based), SmartStart™ automatic recharge logic, 20µA shutdown quiescent current, and integrated P-channel MOSFET eliminating external sense resistor and blocking diode.

Technical Context

The LTC4061EDD#PBF implements a constant-current/constant-voltage (CC/CV) charging algorithm with three-phase operation: trickle charge below 2.9V, constant-current mode up to 1A, then constant-voltage regulation at 4.2V ±0.35%. Its internal thermal feedback loop dynamically reduces charge current when die temperature exceeds ~105°C, enabling robust operation under high ambient or high-power conditions without external thermal management.

Termination is configurable via TIMER pin: capacitor-to-ground enables time-based termination (e.g., 3 hours with 0.1µF), ground enables current-based termination using IDET pin threshold, and VCC enables user-controlled termination via EN. NTC monitoring uses dual comparators (0.35×VCC hot / 0.76×VCC cold) with ~2°C hysteresis, freezing timer and pulsing CHRG at 1.5Hz on fault.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4061EDD#PBF, BQ24075RGTR offers higher current but sacrifices NTC safety and SmartStart longevity benefits, while MAX1555EZK+T simplifies design at the cost of configurability and thermal protection - making LTC4061EDD#PBF optimal for thermally demanding, long-life portable applications.

Availability

LTC4061EDD#PBF is available at Aetrix Electronics and suitable for handheld computers, portable MP3 players, and digital cameras requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for LTC4061EDD#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 and maintains its precision analog and power management portfolio with rigorous automotive and industrial qualification standards.

The LTC4061EDD#PBF belongs to Linear's standalone battery charger IC family, engineered for USB-powered portable electronics where safety, thermal resilience, and battery longevity are primary design goals.

FAQ

What is the maximum charge current supported by the LTC4061EDD#PBF?

The LTC4061EDD#PBF supports a maximum charge current of 1A, programmable via an external resistor connected from the PROG pin to ground. The relationship is I_CHG = 1000 × V_PROG/R_PROG, where V_PROG is regulated to 1V in constant-current mode. At R_PROG = 1.25kΩ, the LTC4061EDD#PBF delivers 800mA; at 1kΩ, it reaches 1A. Current accuracy depends on resistor tolerance and temperature drift.

How does the NTC thermistor interface work on the LTC4061EDD#PBF?

The LTC4061EDD#PBF monitors battery temperature via the NTC pin using two internal comparators: one triggers at 0.35×VCC (hot threshold, ~40°C) and another at 0.76×VCC (cold threshold, ~0°C), each with ~2°C hysteresis. When either threshold is crossed, charging suspends, the internal timer freezes, and the CHRG pin pulses at 1.5Hz. A resistor divider (NTC to GND, RNOM = NTC value at 25°C to VCC) is required; grounding NTC disables the feature.

Can the LTC4061EDD#PBF operate from a standard USB port?

Yes, the LTC4061EDD#PBF is explicitly designed for USB power sources, accepting 4.3V–8V input. Its C/5 pin allows dynamic current limiting: logic high enables full PROG-set current (e.g., 500mA), while logic low reduces it to 20% (e.g., 100mA) to comply with USB 2.0 low-power port limits. Undervoltage lockout (3.8V) and ACPR logic output further ensure robust USB interface behavior.

What happens when the LTC4061EDD#PBF detects a defective battery?

When the LTC4061EDD#PBF remains in trickle-charge mode (>25% of programmed timer duration), it enters FAULT state: the CHRG pin pulses at 6Hz (50% duty cycle) to indicate battery replacement is required. This occurs only with time-based termination enabled. To clear the fault, power must be cycled or the EN pin toggled. The LTC4061EDD#PBF does not attempt further charging until reset, protecting system integrity.

Does the LTC4061EDD#PBF require an external blocking diode or current-sense resistor?

No, the LTC4061EDD#PBF integrates a P-channel power MOSFET and uses the PROG pin's 1V reference to derive charge current - eliminating the need for both an external blocking diode and a sense resistor. This reduces component count, PCB area, and power loss. Thermal regulation and SmartStart™ further enhance reliability without additional discrete parts.