Analog Devices Inc. LT3510EFE

Overview

LT3510EFE from Analog Devices (formerly Linear Technology) is a monolithic dual current-mode PWM step-down DC/DC converter with two internal 2.5A NPN switches, operating from 3.1V to 25V input and delivering independent 2A outputs at adjustable voltages. It supports antiphase switching at 250kHz–1.5MHz, features 95% max duty cycle for low-dropout operation, and is used in DSP power supplies, PCI cards, and wall transformer regulation.

For engineers reviewing the LT3510EFE datasheet, LT3510EFE pinout, LT3510EFE application, or LT3510EFE equivalent, key selection criteria include independent soft-start/PG pins per channel, 180° phase relationship for ripple reduction, exposed-pad 20-lead TSSOP thermal performance, and tracking/sequencing capability across wide input voltage range.

Technical Context

The LT3510EFE implements dual independent current-mode control loops, each with dedicated error amplifier (275μmho gm), VC output, FB input referenced to 0.8V ±2%, and programmable soft-start via SS/TRACK pins. Each channel maintains precise current sensing through IND/VOUT pins and uses BST-driven NPN switches with boost capacitor recharge management.

It integrates synchronized oscillator architecture supporting resistor-programmed (250kHz–1.5MHz) or external clock synchronization with fixed 180° phase offset between channels. Internal undervoltage lockout on VIN1, thermal shutdown, and enhanced short-circuit protection operate across –40°C to 125°C junction temperature range.

Key Specifications

Pinout & Package

LT3510EFE is housed in a 20-lead plastic TSSOP package with exposed leadframe (Pin 21 = GND), providing low θ_JA = 45°C/W and θ_JC(PAD) = 10°C/W for high-power density designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel buck regulator applications.

Compared with LTC3631EMSE and TPS54290PWPR, the LT3510EFE uniquely combines dual independent 2A outputs, antiphase operation, per-channel soft-start and power-good, and exposed-pad thermal design-making it optimal for space-constrained, multi-rail embedded systems requiring precise sequencing and low thermal resistance.

Availability

LT3510EFE is available at Aetrix Electronics and suitable for DSP power supplies, PCI cards, and wall transformer regulation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT3510EFE 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 power management portfolio with rigorous qualification standards.

The LT3510EFE belongs to Linear's monolithic DC/DC converter family designed for high-efficiency, compact, and thermally robust multi-rail power solutions in industrial, telecom, and computing applications.

FAQ

What is the maximum supported switching frequency for LT3510EFE?

The LT3510EFE supports a maximum switching frequency of 1.5MHz when a 15.4kΩ resistor is connected from RT/SYNC to ground. At this frequency, minimum on-time limits practical operation to ~750kHz for 3.3V output from 25V input due to t_ON(MIN) = 200ns at 85°C. The device maintains 180° phase relationship and slope compensation integrity across the full 250kHz–1.5MHz range.

How does LT3510EFE achieve 95% maximum duty cycle?

The LT3510EFE achieves ~95% maximum duty cycle by allowing the internal NPN switch to remain on for multiple clock cycles until the BST capacitor voltage drops below ~1.7V, at which point a minimum off-time is enforced to recharge the boost capacitor. This dropout enhancement avoids reliance on external components and enables high-VIN-to-low-VOUT conversion such as 12V→1.8V with minimal headroom loss.

Can LT3510EFE outputs be paralleled for higher current?

Yes, the LT3510EFE datasheet explicitly states "Outputs Can be Paralleled" in its FEATURES section. Paralleling requires matching feedback resistors, shared RT/SYNC clock source, and careful layout to balance current. Each channel retains independent current limiting, so paralleled operation delivers up to 4A total with inherent current sharing and fault isolation.

What is the role of the exposed pad (Pin 21) on LT3510EFE?

The exposed pad (Pin 21) on LT3510EFE is the sole GND connection for both power and small-signal paths. It must be soldered to a large PCB copper area to achieve θ_JC(PAD) = 10°C/W and ensure thermal reliability at full 2A load per channel. All small-signal grounds should connect to this pad at a single point to avoid noise coupling from high-current return paths.

Does LT3510EFE support external clock synchronization?

Yes, LT3510EFE supports external clock synchronization via the RT/SYNC pin (Pin 16). A clean CMOS/TTL clock signal (250kHz–1500kHz) applied to this pin synchronizes both channels with 180° phase offset, preserves slope compensation, and eliminates beat frequencies. The internal oscillator automatically resumes resistor-programmed operation if the external clock is removed.