Analog Devices Inc. LT3752HFE#WPBF

Overview

LT3752HFE#WPBF from Analog Devices is a high-temperature active clamp synchronous forward controller IC with integrated housekeeping DC/DC controller, supporting 6.5V–100V input, programmable 100kHz–500kHz switching frequency, volt-second clamp for >50% duty cycle, and AOUT/SOUT/OUT gate drivers for primary switch, active clamp MOSFET, and synchronous rectifier - used in isolated 48V telecom and automotive power supplies.

For engineers reviewing the LT3752HFE#WPBF datasheet, LT3752HFE#WPBF pinout, LT3752HFE#WPBF application, or LT3752HFE#WPBF equivalent, key selection criteria include its –40°C to 150°C junction temperature rating, TSSOP-38 package with high-voltage pin spacing, dual-loop control (forward + housekeeping), active clamp timing programmability (tAO/tOA/tSO/tOS), and AEC-Q100 qualification for automotive systems.

Technical Context

The LT3752HFE#WPBF implements current-mode PWM control for active clamp forward topology with adaptive leading edge blanking and programmable slope compensation on both main and housekeeping loops. Its dual-regulator architecture integrates a 7V INTVCC linear regulator (for forward controller) and a separate 10V housekeeping regulator (LT3752-1 variant uses 10V; LT3752HFE#WPBF is LT3752 variant per order info), enabling independent biasing of primary-side and secondary-side control circuits.

It supports open-loop DVSEC volt-second clamp via UVLO_VSEC pin, programmable soft-start/stop via SS1/SS2 pins, hiccup-mode overcurrent protection on ISENSEP and HISENSE inputs, and external clock synchronization via SYNC pin with 1.2–1.8V high threshold. The device distinguishes LT3752 (low-side active clamp) from LT3752-1 (high-side active clamp) - LT3752HFE#WPBF is the LT3752 variant.

Key Specifications

Pinout & Package

The LT3752HFE#WPBF is housed in a 38-lead plastic TSSOP package (FE38 variation) with missing pins for high-voltage creepage and clearance. Exposed pad (Pin 39) is internally connected to PGND and GND and must be soldered to PCB for thermal and electrical integrity. θJA = 25°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar active clamp forward controller applications.

Compared with LT3752IFE#WPBF and LT3752EFE#WPBF, the LT3752HFE#WPBF delivers verified 150°C junction operation and AEC-Q100 compliance - critical for automotive power conversion where thermal margin and qualification traceability are mandatory.

Availability

LT3752HFE#WPBF is available at Aetrix Electronics and suitable for automotive battery converters, 48V telecom isolated PSUs, and industrial HV power supplies requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LT3752HFE#WPBF 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 is a global semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision, power, and connectivity applications.

The LT3752 product line is designed for high-efficiency isolated DC-DC conversion using active clamp forward topology - targeting automotive, telecom, and industrial systems demanding robustness, programmability, and thermal resilience.

FAQ

What is the maximum operating junction temperature for the LT3752HFE#WPBF?

The LT3752HFE#WPBF is guaranteed to operate reliably from –40°C to 150°C junction temperature, with full performance specifications validated across this range. This rating is confirmed in the Absolute Maximum Ratings table and supported by thermal characterization data in the datasheet Rev. C, making it suitable for under-hood automotive and high-ambient industrial deployments where the LT3752HFE#WPBF must sustain continuous operation at elevated temperatures.

Does the LT3752HFE#WPBF support both active clamp and synchronous rectification control?

Yes, the LT3752HFE#WPBF provides three independent gate drivers - OUT for the main primary-side switch, AOUT for the active clamp MOSFET, and SOUT for the secondary-side synchronous rectifier. Each driver features sub-25ns rise/fall times and programmable timing delays (tAO, tOA, tSO, tOS) to optimize zero-voltage switching and prevent shoot-through - a core capability confirmed in the Applications Information section of the LT3752/LT3752-1 datasheet Rev. C.

How does the volt-second clamp (DVSEC) function on the LT3752HFE#WPBF?

The LT3752HFE#WPBF implements DVSEC clamp via the UVLO_VSEC pin, which accepts an analog voltage to set the maximum volt-second product applied to the transformer primary. At UVLO_VSEC = 1.25V, 2.50V, or 5.00V, the corresponding max duty cycles are 72.5%, 36.5%, and 18.6% - enabling >50% duty cycle operation for improved transformer utilization. This function is explicitly detailed in the Electrical Characteristics table on page 7 of the LT3752/LT3752-1 Rev. C datasheet.

Is the LT3752HFE#WPBF pin-compatible with other variants like LT3752IFE#WPBF?

Yes, the LT3752HFE#WPBF shares identical pinout, package (38-lead TSSOP), and functional architecture with LT3752IFE#WPBF and LT3752EFE#WPBF - all belong to the same FE package family and variation FE38(31). Differences are limited to temperature grade and qualification status; no PCB layout changes are required when upgrading from IFE or EFE to HFE grade for enhanced thermal performance.

What protection features does the LT3752HFE#WPBF include?

The LT3752HFE#WPBF integrates short-circuit hiccup-mode overcurrent protection on both main (ISENSEP/OC) and housekeeping (HISENSE) loops, programmable UVLO/OVLO with hysteresis on VIN, INTVCC UVLO/OVLO with 0.15V hysteresis, and soft-stop shutdown via SS1. These protections are fully specified in the Electrical Characteristics tables and validated across the –40°C to 150°C junction range - ensuring robust fault handling in mission-critical automotive and industrial power systems.