Analog Devices Inc. LT3650EDD-8.2#TRPBF

Overview

LT3650EDD-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 - used in 12V–24V automotive cradle chargers and industrial handheld instruments.

For engineers reviewing the LT3650EDD-8.2#TRPBF datasheet, LT3650EDD-8.2#TRPBF pinout, LT3650EDD-8.2#TRPBF application, or LT3650EDD-8.2#TRPBF equivalent, key selection considerations include its 8.2V float voltage accuracy (±0.5%), 1MHz fixed-frequency average current mode control, 0.75mm low-profile 3mm × 3mm DFN-12 package, and dual open-collector status outputs (CHRG/FAULT) for system-level battery state signaling.

Technical Context

The LT3650EDD-8.2#TRPBF implements a constant-current/constant-voltage (CC/CV) charging profile using average current mode control with 1MHz fixed-frequency operation. Its internal 2A switch is driven by a bootstrapped BOOST rail referenced to SW, enabling saturation and minimizing forward drop (350mV at 2A).

It integrates preconditioning (trickle-charge below 5.65V), auto-restart at 97.5% float voltage, bad-battery detection (triggered if precondition persists >22.5 min), and dual termination modes: C/10 current detection (±2.5% accuracy) or user-programmable 3-hour safety timer (±10% accuracy) via TIMER pin capacitor.

Key Specifications

Pinout & Package

LT3650EDD-8.2#TRPBF is housed in a 3mm × 3mm, 0.75mm-thick 12-pin plastic DFN package with exposed thermal pad (Pin 13 = GND). The package is RoHS-compliant and designed for high-density PCB layouts requiring efficient thermal dissipation.

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 LT3650EDD-8.2#TRPBF offers identical performance in a smaller, thermally superior DFN package; compared with BQ24610RVGR, it delivers fully autonomous operation with integrated timer, NTC, and binary status outputs - reducing firmware dependency and component count.

Availability

LT3650EDD-8.2#TRPBF is available at Aetrix Electronics and suitable for 12V–24V automotive cradle chargers, industrial handheld instruments, and desktop battery docking stations requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for LT3650EDD-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 industrial, automotive, communications, and medical markets.

The LT3650EDD-8.2#TRPBF belongs to Linear's high-voltage monolithic battery charger product line, engineered specifically for 9V–32V input systems needing compact, self-contained 2-cell Li-ion charging with minimal external components and robust safety features.

FAQ

What is the exact float voltage of the LT3650EDD-8.2#TRPBF?

The LT3650EDD-8.2#TRPBF is factory-trimmed to deliver a nominal 8.2V float voltage with ±0.5% accuracy over temperature (–40°C to 85°C). This value is specified in the Electrical Characteristics table under VBAT(FLT) for LT3650-8.2 and confirmed by the part marking "82" in the device's top-side laser code LDXT. It is not adjustable and applies exclusively to this variant - the LT3650EDD-8.4#TRPBF delivers 8.4V.

Does the LT3650EDD-8.2#TRPBF support automatic recharge, and at what threshold?

Yes, the LT3650EDD-8.2#TRPBF supports automatic recharge when the battery voltage drops 2.5% below its float voltage - i.e., at 97.5% of 8.2V = 7.995V. This behavior is hard-coded and does not require external configuration. Once the BAT pin voltage falls to this level, the IC exits standby mode and initiates a new CC/CV cycle, ensuring the battery remains at optimal state-of-charge without host intervention.

How is charge current programmed on the LT3650EDD-8.2#TRPBF?

Charge current is programmed via an external sense resistor (R_SENSE) between SENSE and BAT pins, where I_MAX = 0.1V / R_SENSE. For 2A full-scale, R_SENSE = 50mΩ. The RNG/SS pin provides dynamic scaling: sourcing 50µA, it sets a voltage (0–1V) that linearly scales I_MAX - e.g., 0.5V on RNG/SS yields 1A maximum. No DAC or digital interface is required.

What is the function of the CLP pin on the LT3650EDD-8.2#TRPBF?

The CLP pin on the LT3650EDD-8.2#TRPBF enables system-level input current limiting. By connecting a sense resistor between CLP and VIN, the IC monitors total input current and dynamically reduces charge current to hold system draw at a fixed threshold - typically 50mV across the resistor. If unused, CLP must be tied to VIN; floating it may cause erratic behavior.

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

Yes, the LT3650EDD-8.2#TRPBF operates normally without an NTC thermistor. The NTC pin is internally biased with 50µA; if left unconnected (floating), the voltage remains below 0.29V and temperature monitoring is disabled. Charging proceeds with full safety timer and C/10 termination, but thermal protection is inactive - acceptable for controlled-environment applications where battery temperature is externally managed.