Analog Devices Inc. LT3650IMSE-8.2#TRPBF

Overview

LT3650IMSE-8.2#TRPBF 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, and NTC temperature monitoring - designed for industrial handheld instruments and 12V–24V automotive charging systems.

For engineers reviewing the LT3650IMSE-8.2#TRPBF datasheet, LT3650IMSE-8.2#TRPBF pinout, LT3650IMSE-8.2#TRPBF application, or LT3650IMSE-8.2#TRPBF equivalent, key selection criteria include its 8.2V fixed float voltage, 12-pin MSOP package with exposed thermal pad, ±0.5% float voltage accuracy, auto-recharge at 97.5% V_FLT, and bad-battery detection with precondition timeout.

Technical Context

The LT3650IMSE-8.2#TRPBF implements average current mode control with a fixed 1MHz switching frequency, using an internal bootstrapped gate driver to saturate its integrated 2A N-channel switch. Its VIN-to-SW overvoltage clamp (4.5V) and BOOST rail (0–8.5V referenced to SW) enable high-efficiency step-down regulation across wide input ranges.

Charge management integrates dual termination modes: C/10 detection (7.5–12.5mV sense threshold) and user-programmable timer (3-hour default via 0.68µF capacitor), with automatic preconditioning below 5.65V and auto-restart when BAT drops 2.5% below 8.2V float. Status signaling uses binary-coded open-collector CHRG and FAULT pins with 10mA sink capability.

Key Specifications

Pinout & Package

LT3650IMSE-8.2#TRPBF is housed in a 12-lead plastic MSOP package (3mm × 4.9mm) with exposed thermal pad (Pin 13 = GND), rated for –40°C to +85°C operation. The exposed pad must be soldered to PCB ground for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT3650EMSE-8.2#TRPBF, the LT3650IMSE-8.2#TRPBF guarantees full specification compliance at –40°C, critical for automotive and industrial deployments; versus BQ24610RTWR, it delivers lower system-level complexity through monolithic integration of switch, NTC interface, and binary status signaling.

Availability

LT3650IMSE-8.2#TRPBF is available at Aetrix Electronics and suitable for industrial handheld instruments, 12V–24V automotive charging systems, and desktop cradle chargers requiring stable component supply, long-term lifecycle support, and guaranteed temperature-grade compliance.

Supply support for LT3650IMSE-8.2#TRPBF 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 precision instrumentation, automotive, and industrial markets.

The LT3650IMSE-8.2#TRPBF belongs to Linear's high-voltage monolithic battery charger product line, engineered specifically for robust, low-component-count charging of 2-cell Li-ion batteries from unregulated 12V/24V sources in harsh environments.

FAQ

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

The LT3650IMSE-8.2#TRPBF has a factory-trimmed fixed float voltage of 8.2V, with guaranteed accuracy of ±0.5% (8.16V to 8.24V) over the full –40°C to +85°C temperature range. This value is laser-trimmed during production and cannot be adjusted externally - it is specific to the "-8.2" variant, distinguishing it from the 8.4V LT3650-8.4 family members.

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

Yes, the LT3650IMSE-8.2#TRPBF automatically initiates a new charge cycle when the battery voltage at the BAT pin falls 2.5% below its 8.2V float voltage - i.e., at 7.995V. This behavior is inherent to the IC's design and requires no external circuitry or host intervention, making it ideal for maintenance-free battery-powered systems.

Can the LT3650IMSE-8.2#TRPBF be used with a 10V input supply?

No - the LT3650IMSE-8.2#TRPBF requires a minimum input voltage of 11.5V to start up, even though its operational range extends down to 9V once running. At 10V, the device will not initiate switching; startup is enabled only when VIN ≥ 11.5V or when the BOOST–SW differential exceeds 2V, per the Absolute Maximum Ratings table.

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

Maximum charge current on the LT3650IMSE-8.2#TRPBF is set by an external sense resistor (R_SENSE) between SENSE and BAT pins, where I_MAX = 0.1V / R_SENSE. For example, a 0.05Ω resistor yields 2A. The RNG/SS pin further enables dynamic adjustment (0–1V input) or soft-start via external RC network, without altering R_SENSE.

What thermal management is required for the LT3650IMSE-8.2#TRPBF in continuous 2A operation?

The LT3650IMSE-8.2#TRPBF requires its exposed thermal pad (Pin 13) to be soldered to a minimum 200mm² copper pour on the PCB for effective heat dissipation. With θ_JA = 43°C/W, continuous 2A operation at 24V input may raise junction temperature by ~40°C above ambient - sufficient derating margin exists for 85°C ambient, provided the pad is properly connected.