Texas Instruments LM5117EVAL/NOPB

Overview

LM5117EVAL/NOPB from Texas Instruments is a fully assembled evaluation board for the LM5117 synchronous buck controller IC, implementing emulated current-mode control to deliver 12V at up to 9A output current from a 15V–55V input range. It supports diode emulation, hiccup-mode overload protection, external VCC sourcing, and clock synchronization via SYNC pin.

For engineers reviewing the LM5117EVAL/NOPB datasheet, LM5117EVAL/NOPB pinout, LM5117EVAL/NOPB application, or LM5117EVAL/NOPB equivalent, this board enables rapid validation of high-voltage synchronous buck converter performance-including efficiency, load transient response, soft-start behavior, loop stability, and hiccup-mode fault recovery-under real-world thermal and layout conditions.

Technical Context

The LM5117EVAL/NOPB implements a fixed-frequency (230 kHz nominal), emulated current-mode synchronous buck topology using the LM5117 HTSSOP-20 controller. It integrates gate drivers for high-side and low-side N-channel MOSFETs (PSMN5R5-60YS), supports external clock synchronization via TP3, and provides programmable hiccup-mode restart timing through C20.

Board-level features include remote current monitoring (J5 RCA jack), UVLO-based shutdown (TP5), dual test points (TP6/TP7) for loop transfer function measurement, and configurable external VCC sourcing (D1/R7) to reduce controller power dissipation at high input voltages.

Key Specifications

Availability

LM5117EVAL/NOPB is available at Aetrix Electronics and suitable for industrial power supply validation, telecom rectifier prototyping, and high-voltage DC-DC converter development requiring stable component supply, traceable sourcing, and long-term design-in support.

Supply support for LM5117EVAL/NOPB 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 leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability power conversion solutions.

The LM5117EVAL/NOPB belongs to TI's high-voltage buck controller evaluation platform family, designed specifically to accelerate development of robust, efficient synchronous buck converters for 12V–48V input systems in industrial, telecom, and automotive auxiliary power applications.

FAQ

What is the primary function of the LM5117EVAL/NOPB?

The LM5117EVAL/NOPB is an evaluation board-not a standalone IC-that demonstrates the LM5117 synchronous buck controller in a complete, tested 12V/9A power stage. It enables engineers to validate performance metrics including efficiency, transient response, soft-start behavior, and hiccup-mode protection before committing to custom PCB design. The LM5117EVAL/NOPB includes all necessary passives, MOSFETs, and test points for direct measurement and system integration testing.

Does the LM5117EVAL/NOPB support external clock synchronization?

Yes, the LM5117EVAL/NOPB supports external clock synchronization via TP3 (SYNC test point), allowing alignment of the internal oscillator to an external timing source to reduce EMI through frequency dithering or multi-phase interleaving. This feature is confirmed in Section 3.5.4 of the AN-2103 user guide, which documents synchronized switching waveforms with a 20% duty-cycle external clock applied to TP3 while operating at 48V input and 9A load.

How is overload protection implemented on the LM5117EVAL/NOPB?

The LM5117EVAL/NOPB uses hiccup-mode overload protection, triggered when output current exceeds safe limits. Upon fault detection, the LM5117 disables switching, waits for a programmable restart delay set by capacitor C20, then attempts recovery. Figure 4 in the user guide shows this behavior during an output short, with periodic SW voltage pulses and inductor current bursts spaced ~20ms apart-confirming hiccup operation is active and field-validated on the LM5117EVAL/NOPB.

Can the LM5117EVAL/NOPB be used for loop compensation analysis?

Yes, the LM5117EVAL/NOPB includes dedicated test points TP6 and TP7 to inject and monitor signals for measuring the control-to-output loop transfer function. Section 3.7.1 explicitly references AN-1889 for methodology, confirming that the board is configured with appropriate AC coupling and impedance matching to support accurate Bode plot acquisition-making the LM5117EVAL/NOPB suitable for stability analysis and compensation network optimization.

What thermal management is required for full-load operation of the LM5117EVAL/NOPB?

Prolonged full-load operation (9A at 55V input) requires forced airflow of at least 200 linear feet per minute (LFM) to prevent MOSFET overheating, as specified in Section 3.4 of the user guide. Without adequate cooling, Q1 and Q2 (PSMN5R5-60YS) exceed safe junction temperatures, risking thermal shutdown or reliability degradation. The LM5117EVAL/NOPB layout and component selection assume this airflow level for validated 9A continuous performance.