STMicroelectronics EVAL5987

Overview

EVAL5987 from STMicroelectronics is an evaluation board for the L5987 3 A step-down switching regulator IC, designed to demonstrate and validate DC-DC conversion in industrial and consumer power supply designs. It supports input voltages from 2.9 V to 18 V, delivers up to 3 A output current, features adjustable 0.6 V–VIN output voltage, 250 kHz–1 MHz programmable switching frequency, and includes thermal/overcurrent protection with VFQFPN-8 and HSOP-8 package compatibility.

For engineers reviewing the EVAL5987 datasheet, EVAL5987 pinout, EVAL5987 application, or EVAL5987 equivalent, this board enables rapid validation of L5987-based buck converter performance-including soft-start behavior, synchronization capability, feedback loop stability with Type II/III compensation, and thermal derating under real load conditions-prior to custom PCB design.

Technical Context

The EVAL5987 implements a complete reference design for the L5987 voltage-mode synchronous buck controller, featuring external MOSFET drive (P-channel high-side), integrated error amplifier, and feedforward-enhanced PWM modulation. It supports both VFQFPN-8 and HSOP-8 variants of the L5987, with layout-optimized power paths and thermal vias aligned to each package's exposed pad requirements.

It enables functional verification of key L5987 features: INH-controlled enable/disable sequencing, SYNCH master/slave synchronization (180° phase shift), FSW resistor-programmable frequency scaling, and FB-based output voltage regulation with external resistor divider. The board includes test points for COMP, FB, FSW, and SYNCH to support loop analysis and timing measurements.

Key Specifications

Availability

EVAL5987 is available at Aetrix Electronics and suitable for industrial PLCs, consumer audio systems, networking DC-DC modules, and FPGA/PLD core power supplies requiring stable component supply, fast prototyping turnaround, and production-ready reference validation.

Supply support for EVAL5987 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

STMicroelectronics is a global semiconductor leader specializing in power management, microcontrollers, and analog ICs, with over 30 years of automotive-grade reliability and industrial application focus.

The EVAL5987 belongs to ST's Power Management Evaluation Kit product line, engineered to accelerate adoption of its high-efficiency DC-DC regulators-specifically targeting engineers designing compact, thermally robust, and EMI-conscious buck converters for space-constrained applications.

FAQ

Does EVAL5987 support both VFQFPN-8 and HSOP-8 versions of the L5987?

Yes. The board includes dual footprint layouts and jumper-selectable thermal pad connections to accommodate either the VFQFPN-8 (R_thJA = 60 °C/W) or HSOP-8 (R_thJA = 40 °C/W) package variants of the L5987, enabling direct thermal performance comparison under identical test conditions.

Can I synchronize two EVAL5987 boards using the SYNCH pin?

Yes. The SYNCH pin is routed to a test point and header, allowing master/slave configuration: connecting SYNCH pins of two boards causes the higher-frequency unit to act as master, synchronizing the other with 180° phase shift-reducing input ripple RMS current as confirmed in L5987 application note Section 5.1.

What compensation network options does EVAL5987 support?

EVAL5987 provides unpopulated footprints and test points for both Type II (for low-ESR ceramic output capacitors) and Type III (for higher-ESR electrolytic/tantalum caps) compensation networks, with direct access to COMP and FB nodes for oscilloscope probing and loop gain measurement per Section 6.4 of the L5987 datasheet.

Is soft-start duration adjustable on EVAL5987?

No-the soft-start time is fixed by the internal staircase ramp (64 × 9.5 mV steps, 32 clock cycles per step) and scales inversely with switching frequency (e.g., ~8.2 ms at 250 kHz, ~2.1 ms at 1 MHz). The board exposes the FSW pin to allow frequency adjustment, thereby indirectly tuning soft-start duration per Equation 2 in the L5987 datasheet.