Analog Devices Inc. LT3652EMSE#TRPBF

Overview

LT3652EMSE#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic 2A step-down battery charger IC with integrated 35V/2.5A switch, designed for solar-powered LiFePO₄, Li-ion, and SLA battery systems. It delivers constant-current/constant-voltage charging, supports input voltage regulation for MPPT, features 0.5% float voltage accuracy, 5% charge current accuracy, and operates across 4.95V–32V input with 14.4V programmable float voltage - used in remote solar monitoring stations and 12V–24V automotive auxiliary power systems.

For engineers reviewing the LT3652EMSE#TRPBF datasheet, LT3652EMSE#TRPBF pinout, LT3652EMSE#TRPBF application, or LT3652EMSE#TRPBF equivalent, key selection considerations include its 12-lead MSOP package with exposed thermal pad, C/10 or timer-based termination, NTC temperature monitoring, auto-recharge at 2.5% float voltage drop, and compatibility with peak power tracking in photovoltaic inputs up to 40V open-circuit.

Technical Context

The LT3652EMSE#TRPBF implements average-current-mode control with a fixed 1MHz switching frequency and bootstrapped gate drive for its internal N-channel MOSFET switch. Its input voltage regulation loop dynamically adjusts charge current to maintain VIN_REG ≥ 2.7V - enabling true maximum power point tracking when powered by solar panels.

It integrates dual termination logic: C/10 detection (2.5% accuracy) and a programmable safety timer (±10% accuracy, typical 3-hour full-cycle timeout), plus preconditioning for deeply discharged batteries (15% max current until VBAT reaches 70% of float voltage). The 3.3V VFB reference enables resistor-programmable float voltages up to 14.4V with 0.5% initial accuracy over –40°C to 125°C.

Key Specifications

Pinout & Package

LT3652EMSE#TRPBF uses a 12-lead plastic MSOP package (3mm × 4.9mm) with exposed thermal pad (Pin 13 = GND), rated for –40°C to 125°C junction temperature. The exposed pad must be soldered to PCB ground for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery charger applications.

Compared with LT3652EMSE#TRPBF, the LT3652EDD#TRPBF offers identical functionality in a thermally superior DFN package, while the BQ24616RTWR provides broader chemistry support but requires external components to replicate MPPT and NTC functions - making LT3652EMSE#TRPBF optimal for solar-integrated LiFePO₄ systems needing minimal BOM count.

Availability

LT3652EMSE#TRPBF is available at Aetrix Electronics and suitable for solar-powered remote monitoring stations, LiFePO₄-based automotive auxiliary power systems, and portable handheld instruments requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LT3652EMSE#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 and maintains its high-performance analog IC portfolio, emphasizing precision power management, signal conditioning, and robust industrial-grade reliability.

The LT3652EMSE#TRPBF belongs to Linear's dedicated battery charger product line, engineered specifically for high-input-voltage, multi-chemistry energy harvesting applications - especially solar-powered systems requiring integrated MPPT, thermal safety, and autonomous recharge behavior.

FAQ

What is the maximum input voltage rating for the LT3652EMSE#TRPBF?

The LT3652EMSE#TRPBF has an absolute maximum input voltage rating of 40V on the VIN pin. Its operational input range is specified from 4.95V to 32V. Exceeding 40V may cause permanent damage. For solar applications, this allows direct connection to panels with up to 40V open-circuit voltage while maintaining reliable operation within the 4.95–32V functional window. The LT3652EMSE#TRPBF includes internal overvoltage protection that triggers at 32V (rising) with 3V hysteresis.

How does the LT3652EMSE#TRPBF implement maximum power point tracking (MPPT)?

The LT3652EMSE#TRPBF implements hardware-based MPPT via its VIN_REG pin and internal regulation loop. By connecting a resistor divider from VIN to VIN_REG, the user sets a target input voltage (e.g., panel's V_MPP). The IC continuously reduces charge current to prevent VIN_REG from falling below 2.7V, thereby holding the input source at its peak power point. This analog servo loop requires no MCU or software, enabling >98% MPPT efficiency as confirmed in typical application circuits. The LT3652EMSE#TRPBF does not perform digital hill-climbing or perturb-and-observe algorithms.

Can the LT3652EMSE#TRPBF charge a 24V LiFePO₄ battery pack?

Yes, the LT3652EMSE#TRPBF can charge a 24V LiFePO₄ pack (typically 8S configuration, 28.8V float) because its resistor-programmable float voltage supports up to 14.4V per 2-cell subpack. For a full 8S pack, two LT3652EMSE#TRPBF devices can be used in series-oriented configurations with isolated feedback, or a single LT3652EMSE#TRPBF can manage a 4S subpack (14.4V) within its 14.4V limit. Direct 24V+ float programming is not supported - the LT3652EMSE#TRPBF's VFB reference and internal architecture cap float voltage at 14.4V.

What happens if the NTC thermistor is disconnected from the LT3652EMSE#TRPBF?

If the NTC thermistor is left unconnected, the LT3652EMSE#TRPBF disables the temperature monitoring function entirely. The NTC pin has a 250kΩ disable impedance threshold; with no thermistor, leakage current keeps the pin voltage outside the active 0.29V–1.36V window, and the IC proceeds with normal charging. No fault is asserted, CHRG and FAULT remain functional, and all other features (MPPT, C/10, timer) operate unchanged. The LT3652EMSE#TRPBF datasheet explicitly states this is the recommended method to disable thermal monitoring.

Does the LT3652EMSE#TRPBF require an external blocking diode on the VIN input?

No, the LT3652EMSE#TRPBF does not require an external blocking diode on VIN when charging batteries with float voltages ≤4.2V, due to its internal reverse-current protection (<1µA). For higher-voltage batteries (e.g., 7.2V LiFePO₄ or 14.4V SLA), a Schottky diode is recommended to prevent battery discharge back through the input path during VIN absence. The LT3652EMSE#TRPBF's internal architecture eliminates the diode drop and associated power loss only in low-voltage configurations - it does not provide full bidirectional isolation for all chemistries.