Analog Devices Inc. LT3650IMSE-8.2#PBF

Overview

LT3650IMSE-8.2#PBF from Analog Devices (formerly Linear Technology) is a monolithic 2-cell Li-Ion/Polymer battery charger IC with 8.2V float voltage, 9V–32V input range, 2A max charge current, ±0.5% float voltage accuracy, and integrated C/10 or timer-based termination. It operates in average current mode control at 1MHz and supports preconditioning, NTC temperature monitoring, and auto-recharge for industrial handheld instruments and 12V–24V automotive systems.

For engineers reviewing the LT3650IMSE-8.2#PBF datasheet, LT3650IMSE-8.2#PBF pinout, LT3650IMSE-8.2#PBF application, or LT3650IMSE-8.2#PBF equivalent, key selection considerations include its 12-pin MSOP package, 8.2V fixed float voltage, programmable input current limit via CLP pin, dynamic charge rate adjustment via RNG/SS, and binary-coded open-collector status outputs (CHRG/FAULT).

Technical Context

The LT3650IMSE-8.2#PBF implements a fixed-frequency (1MHz) average current mode step-down architecture with an internal 2A switch driven by a bootstrapped BOOST rail. Its control loop directly regulates average inductor current using SENSE–BAT differential voltage feedback and integrates voltage error (V-EA) and current error (C-EA) amplifiers to maintain precise CC/CV charging profiles.

It features dual termination schemes: C/10 detection (7.5–12.5mV sense threshold) or user-programmable timer (3-hour default via 0.68µF capacitor on TIMER pin), with bad-battery detection triggered if preconditioning exceeds 22.5 minutes. The IC enters 85µA standby when charging terminates and auto-restarts when BAT voltage drops 2.5% below 8.2V float.

Key Specifications

Pinout & Package

LT3650IMSE-8.2#PBF is housed in a 12-lead plastic MSOP package (3mm × 3mm, 0.75mm height) with exposed thermal pad (Pin 13 = GND). Pin assignments are validated per Linear Technology's official Datasheet Rev. D (36508284fd).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC4000-8.2#PBF and BQ24610RGER, the LT3650IMSE-8.2#PBF delivers a fully integrated, thermally optimized solution for mid-power 2-cell charging-eliminating external switch losses, reducing component count, and embedding safety-critical functions like preconditioning and NTC monitoring without added circuitry.

Availability

LT3650IMSE-8.2#PBF is available at Aetrix Electronics and suitable for industrial handheld instruments, 12V–24V automotive systems, desktop cradle chargers, and notebook computers requiring stable component supply across extended temperature ranges.

Supply support for LT3650IMSE-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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.

The LT3650 product line was designed specifically for high-input-voltage, monolithic Li-ion battery charging in space-constrained industrial and automotive applications-emphasizing integration, precision, and built-in safety features without external complexity.

FAQ

What is the exact float voltage of the LT3650IMSE-8.2#PBF?

The LT3650IMSE-8.2#PBF has a fixed nominal float voltage of 8.2V, with guaranteed accuracy of ±0.5% (8.16V to 8.28V) over the full –40°C to 85°C operating temperature range. This value is laser-trimmed at wafer test and applies specifically to the -8.2 variant; it is not adjustable and differs from the 8.4V version (LT3650-8.4).

Does the LT3650IMSE-8.2#PBF support automatic recharge after battery voltage drops?

Yes, the LT3650IMSE-8.2#PBF automatically initiates a new charge cycle when the battery voltage at the BAT pin falls 2.5% below the 8.2V float voltage - i.e., at approximately 8.0V. This behavior occurs in standby mode and does not require external intervention or microcontroller polling.

Can the LT3650IMSE-8.2#PBF be used with a 12V input supply?

Yes, the LT3650IMSE-8.2#PBF operates reliably with 12V input, as its specified input range is 9V to 32V. Startup requires VIN ≥11.5V or BOOST–SW >2V; therefore, 12V is fully supported for both startup and continuous operation in applications such as automotive accessories and industrial power supplies.

How is charge current programmed on the LT3650IMSE-8.2#PBF?

Charge current is set by an external sense resistor (R_SENSE) between SENSE and BAT pins, where R_SENSE = 0.1V / I_CHG(MAX). For example, a 50mΩ resistor programs 2A maximum current. The RNG/SS pin further enables dynamic adjustment or soft-start by scaling the effective sense voltage reference.

What package type and temperature grade does the LT3650IMSE-8.2#PBF have?

The LT3650IMSE-8.2#PBF uses a 12-lead plastic MSOP package (3mm × 3mm) and is rated for operation from –40°C to +85°C. The "I" grade denotes industrial temperature qualification, with all electrical specifications guaranteed across this full range per the datasheet.