Analog Devices Inc. LT3650EDD-8.2#PBF

Overview

LT3650EDD-8.2#PBF from Analog Devices (formerly Linear Technology) is a monolithic 2-cell Li-Ion/Polymer battery charger IC with integrated 2A switch, operating from 9V to 32V input and delivering 8.2V float voltage. It features programmable charge current up to 2A via external sense resistor, C/10 or timer-based termination (3-hour default), and NTC-based temperature monitoring. It targets high-voltage industrial battery systems requiring autonomous, fault-resilient charging.

For engineers reviewing the LT3650EDD-8.2#PBF datasheet, LT3650EDD-8.2#PBF pinout, LT3650EDD-8.2#PBF application, or LT3650EDD-8.2#PBF equivalent, key selection criteria include its 8.2V float accuracy (±0.5%), 1MHz average-current-mode control, 12-pin DFN package with exposed thermal pad, and dual termination modes for reliable 2-cell Li-ion battery management in automotive and portable industrial equipment.

Technical Context

The LT3650EDD-8.2#PBF implements a fixed-frequency (1MHz) average current mode buck converter architecture with internal 2A power switch and bootstrapped gate drive. Its control loop directly regulates average inductor current via SENSE–BAT differential voltage, while maintaining precise 8.2V float voltage using a trimmed internal reference.

It integrates dual termination logic: C/10 detection (7.5–12.5mV sense threshold) and user-programmable timer (via 0.68µF capacitor for 3-hour full cycle). Preconditioning activates below 5.65V battery voltage, reducing charge current to 15% of programmed maximum, and bad-battery detection triggers if precondition persists beyond 22.5 minutes.

Key Specifications

Pinout & Package

LT3650EDD-8.2#PBF is housed in a 12-lead (3mm × 3mm) plastic DFN package with exposed thermal pad (Pin 13 = GND), optimized for high-power density and thermal performance in space-constrained industrial chargers.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 2-cell Li-ion charger applications.

Compared with LT3650EDD-8.2#PBF, the LT3650EMSE-8.2#PBF offers identical performance in a through-hole-compatible package, while the BQ24610RGER trades monolithic integration for higher current and configurability-making the LT3650EDD-8.2#PBF optimal for thermally constrained, high-reliability 2A 2S applications.

Availability

LT3650EDD-8.2#PBF is available at Aetrix Electronics and suitable for industrial handheld instruments, 12V to 24V automotive systems, and desktop cradle chargers requiring stable component supply, long lifecycle support, and guaranteed lead-free compliance.

Supply support for LT3650EDD-8.2#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, Inc. (ADI) acquired Linear Technology in 2017 and maintains its high-performance analog and power management portfolio with rigorous reliability standards and automotive-grade qualification.

The LT3650 product line delivers monolithic, high-input-voltage Li-ion chargers for industrial and automotive applications where wide VIN range, autonomous fault handling, and minimal external components are critical design requirements.

FAQ

What is the exact float voltage specification for the LT3650EDD-8.2#PBF?

The LT3650EDD-8.2#PBF is factory-trimmed to deliver a nominal 8.2V battery float voltage with ±0.5% accuracy over temperature (–40°C to 85°C). This value is fixed per the "-8.2" suffix and differs from the -8.4 variant; it ensures precise termination for two-series Li-ion cells without external feedback resistors.

How does the LT3650EDD-8.2#PBF handle deeply discharged batteries?

The LT3650EDD-8.2#PBF automatically enters precondition mode when BAT voltage falls below 5.65V, reducing charge current to 15% of the programmed maximum. It monitors battery response and suspends charging with FAULT assertion if voltage fails to rise above this threshold within 22.5 minutes-preventing unsafe charging of damaged cells.

Can the LT3650EDD-8.2#PBF operate without an NTC thermistor?

Yes-the NTC pin on the LT3650EDD-8.2#PBF is optional. Leaving it unconnected disables temperature monitoring; the IC will continue normal charging. If used, a 10kΩ, B = 3380 NTC must be connected from NTC to GND, with the IC sourcing 50µA to enable 0°C to 40°C window detection and automatic charge suspension outside that range.

What is the recommended capacitor value for the TIMER pin on the LT3650EDD-8.2#PBF?

A 0.68µF capacitor from TIMER to GND configures the LT3650EDD-8.2#PBF for a standard 3-hour full-charge cycle timeout and 22.5-minute precondition timeout. The relationship is t_EOC = C_TIMER × 4.4 × 10⁶ seconds; values outside 0.47µF–1µF may compromise timer accuracy or fault detection timing margins.

Does the LT3650EDD-8.2#PBF require external MOSFETs or diodes?

No-the LT3650EDD-8.2#PBF integrates a 2A internal power switch and relies on an external Schottky diode (or synchronous rectifier controller) and inductor for buck conversion. It does not require external high-side or low-side MOSFETs, making it a true monolithic solution with only passive components needed for complete 2-cell charging.