Analog Devices Inc. LTC3525LESC6-3#TRMPBF

Overview

LTC3525LESC6-3#TRMPBF from Analog Devices (formerly Linear Technology) is a micropower synchronous step-up DC/DC converter with output disconnect, designed for ultra-low-voltage start-up (0.7V typical) and fixed 3V output regulation in single-cell alkaline/NiMH battery systems. It integrates 0.5Ω N-channel and 0.85Ω P-channel MOSFETs, delivers up to 160mA at 3V from 1.8V input, and operates with 7µA quiescent current in Burst Mode®.

For engineers reviewing the LTC3525LESC6-3#TRMPBF datasheet, LTC3525LESC6-3#TRMPBF pinout, LTC3525LESC6-3#TRMPBF application, or LTC3525LESC6-3#TRMPBF equivalent, key selection criteria include guaranteed 0.88V start-up voltage, true output disconnect for zero shutdown current, anti-ringing control, thermal shutdown, and SC70-6 package compatibility with space-constrained portable instrumentation.

Technical Context

The LTC3525LESC6-3#TRMPBF uses a hysteretic Burst Mode® architecture with adaptive peak/valley inductor current control: peak current scales from 150mA (light load) to 400mA (heavy load) to optimize efficiency across operating conditions. Its start-up oscillator enables operation from 0.7V input, and internal UVLO ensures reliable turn-on only when VIN exceeds 0.88V.

During normal operation, synchronous rectification is enabled once VOUT exceeds VIN by ≥0.2V; below that threshold, the P-channel device acts as a follower to limit inrush. Output disconnect is implemented via internal switch isolation between VOUT and VIN during shutdown, eliminating reverse current and enabling zero-load leakage.

Key Specifications

Pinout & Package

Package: 6-pin SC70 (1.8mm × 1.3mm × 0.9mm height), JEDEC MO-203 AB, EIAJ SC-70 compliant. Thermal resistance θ_JA = 120°C/W on ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-up converter applications.

Compared with LTC3525LESC6-3#TRMPBF, LTC3429ESC6#TRMPBF trades lower quiescent current for higher output current and fixed-frequency operation, while LTC3400EDD#TRMPBF offers greater peak current and wider input range but lacks output disconnect and occupies more PCB area-making LTC3525LESC6-3#TRMPBF optimal for space- and battery-life–critical single-cell applications.

Availability

LTC3525LESC6-3#TRMPBF is available at Aetrix Electronics and suitable for portable medical devices, battery-powered instrumentation, consumer audio players, and compact imaging systems requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LTC3525LESC6-3#TRMPBF 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 full product support, documentation, and manufacturing continuity for all Linear-branded power management ICs.

The LTC3525L family was designed specifically for micropower, single-cell–fed portable electronics requiring ultra-low start-up voltage, true output disconnect, and minimal external components-targeting glucose meters, handheld test equipment, and compact audio devices.

FAQ

What is the minimum input voltage required for the LTC3525LESC6-3#TRMPBF to start switching?

The LTC3525LESC6-3#TRMPBF guarantees start-up at 0.88V and typically starts at 0.7V under standard conditions. This allows reliable operation from partially discharged single-cell alkaline or NiMH batteries. The start-up oscillator remains active until VOUT exceeds VIN by at least 0.2V and either VIN or VOUT reaches 1.8V, ensuring robust initialization even with high-impedance sources.

Does the LTC3525LESC6-3#TRMPBF provide true output disconnect, and how does it affect system design?

Yes, the LTC3525LESC6-3#TRMPBF provides true output disconnect via an internal switch that isolates VOUT from VIN when SHDN is pulled low. This feature eliminates reverse current flow and inrush surge during power-up, enabling zero shutdown current (<1µA). In system design, it removes the need for external blocking diodes or MOSFETs, simplifying BOM and improving battery shelf life in devices like glucose meters and portable instruments.

What is the maximum continuous output current the LTC3525LESC6-3#TRMPBF can deliver at 3V, and what input voltage is required?

The LTC3525LESC6-3#TRMPBF delivers 160mA continuously at 3V output when supplied from a 1.8V input, as confirmed in the Typical Application schematic and Electrical Characteristics table. At 1V input, it supports 65mA. These values assume recommended 10µF output capacitance and proper thermal layout; derating applies above 85°C ambient due to thermal shutdown activation at 125°C junction temperature.

How does Burst Mode® operation in the LTC3525LESC6-3#TRMPBF improve light-load efficiency?

Burst Mode® operation in the LTC3525LESC6-3#TRMPBF improves light-load efficiency by disabling switching until output voltage drops below regulation threshold, then delivering a short burst of pulses to recharge the output capacitor. This reduces average quiescent current to 7µA and maintains >85% efficiency down to 1mA load-critical for battery-powered devices with long idle periods, such as remote sensors or handheld medical tools using the LTC3525LESC6-3#TRMPBF.

Can the LTC3525LESC6-3#TRMPBF operate with input voltage equal to or higher than its 3V output?

Yes, the LTC3525LESC6-3#TRMPBF supports VIN ≥ VOUT operation (e.g., 3.3V input to 3V output), but in this mode the synchronous rectifier is disabled, resulting in lower efficiency and reduced output current capability. The device maintains regulation using the N-channel switch alone, with power delivered through body-diode conduction of the P-channel MOSFET. For optimal performance, VIN should remain below VOUT unless system architecture specifically requires pass-through operation.