Texas Instruments LM5156HEVM-FLY

Overview

LM5156HEVM-FLY from Texas Instruments is an evaluation module designed to demonstrate the LM5156xH non-synchronous flyback controller in a functional flyback power supply configuration. It supports input voltages from 3.5 V to 60 V, delivers primary-side regulated output without optocoupler, and operates up to 2.2 MHz switching frequency for compact magnetics and reduced EMI. The board implements junction-to-top thermal characterization per ψ_JT = 2.0 °C/W.

For engineers reviewing the LM5156HEVM-FLY datasheet, LM5156HEVM-FLY application notes, LM5156HEVM-FLY layout guidelines, or LM5156HEVM-FLY thermal performance data, this module provides validated reference design, WEBENCH®-compatible schematics, and junction-to-top thermal metrics critical for high-temperature industrial and battery-powered flyback systems requiring ≤150°C operation.

Technical Context

The LM5156HEVM-FLY implements the LM5156H controller in a flyback topology with primary-side regulation enabled by integrated error amplifier and accurate ±1% feedback reference. It uses peak-current-mode control with programmable slope compensation, 100-mV ±7% current limit threshold, and 1.5-A MOSFET gate driver to support wide-input, high-efficiency isolated conversion.

Thermal design centers on the HTSSOP-14 package's exposed pad (EP), connected to AGND and large copper plane to achieve ψ_JT = 2.0 °C/W and R_θJA = 54.7 °C/W - enabling reliable operation at 150°C maximum junction temperature under sustained load conditions.

Key Specifications

Availability

LM5156HEVM-FLY is available at Aetrix Electronics and suitable for industrial power supplies, PoE-powered devices, portable speaker amplifiers, and battery-backed flyback converters requiring stable component supply, thermal validation, and reference design fidelity.

Supply support for LM5156HEVM-FLY 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

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in power management ICs and evaluation platforms.

The LM5156xH product line delivers wide-input, high-temperature boost/SEPIC/flyback controllers targeting battery-powered, automotive, and industrial applications where input transients, space constraints, and thermal reliability are critical.

FAQ

What is the primary purpose of the LM5156HEVM-FLY evaluation module?

The LM5156HEVM-FLY is a fully assembled and tested evaluation board that demonstrates the LM5156H controller in a flyback configuration with primary-side regulation. It validates key features including 3.5–60 V input operation, 2.2 MHz switching, junction-to-top thermal characterization (ψ_JT = 2.0 °C/W), and optocoupler-free feedback - enabling rapid prototyping of isolated power supplies for industrial and portable applications.

Does the LM5156HEVM-FLY support boost or SEPIC topologies out of the box?

No. The LM5156HEVM-FLY is specifically configured as a flyback converter with transformer-based isolation and primary-side regulation. While the underlying LM5156H IC supports boost and SEPIC topologies, this evaluation module's layout, component selection, and test points are dedicated to flyback operation - including transformer mounting, snubber network, and feedback divider optimized for isolated output sensing.

How is thermal performance characterized on the LM5156HEVM-FLY?

The LM5156HEVM-FLY provides measured junction-to-top thermal resistance ψ_JT = 2.0 °C/W - a critical parameter for surface-mount thermal modeling when attaching heatsinks or thermal interface materials directly to the package top surface. This value was obtained under standardized JEDEC conditions and complements R_θJA = 54.7 °C/W and R_θJB = 20.7 °C/W for comprehensive thermal analysis of the LM5156HEVM-FLY implementation.

Can the LM5156HEVM-FLY be used to evaluate hiccup mode overload protection?

No. The LM5156HEVM-FLY is built around the LM5156H controller, which has hiccup mode protection disabled. Hiccup mode is only available in the LM51561H variant. To evaluate hiccup behavior, users must substitute the LM51561H IC onto the LM5156HEVM-FLY board - though doing so requires verifying compatibility of all supporting components and firmware settings per the device comparison table in the datasheet.

Is WEBENCH® Power Designer support available for the LM5156HEVM-FLY design?

Yes. The LM5156HEVM-FLY schematic and bill of materials are fully compatible with TI's WEBENCH® Power Designer tool. Users can import the reference design, adjust input/output specifications, simulate performance, and generate optimized component values - including transformer turns ratio, compensation network, and thermal derating curves - directly from the LM5156HEVM-FLY baseline configuration.