STMicroelectronics EVAL5988D

Overview

EVAL5988D from STMicroelectronics is an evaluation board for the L5988D 4 A synchronous step-down DC-DC regulator IC, designed to demonstrate full operation of the HTSSOP16-packaged controller in real-world power conversion applications. It supports input voltages from 2.9 V to 18 V, delivers up to 4 A continuous output current (5 A pulsed), and enables programmable switching frequency up to 1 MHz with voltage feed-forward control, UVLO selection for 3.3 V/5 V/12 V buses, and pre-bias startup - validated in LCD TV, industrial DC-DC modules, and HC LED driving.

For engineers reviewing the EVAL5988D datasheet, EVAL5988D pinout, EVAL5988D application, or EVAL5988D equivalent, this board provides verified reference design implementation, thermal performance validation on ST's demonstration layout, and configurable protection features including latched/non-latched OVP, dual-switch current limiting, and sink capability control - critical for rapid prototyping of high-efficiency buck converters in consumer, networking, and industrial systems.

Technical Context

The EVAL5988D implements a voltage-mode control architecture using a sawtooth oscillator synchronized via the SYNCH pin, enabling stable regulation across wide VIN–VOUT ratios (e.g., 12 V → 1.2 V) without current-sense dependency. Its internal block integrates a 1.8 V ±2% reference, error amplifier with COMP pin for Type II/III compensation, and multifunction U/O/S pin for simultaneous configuration of UVLO thresholds, OVP latch mode, and sink enable/disable.

It validates the L5988D's BCD6 process advantages: 35 mΩ (NMOS) / 50 mΩ (PMOS) typical RDS(on), 200 ns minimum on-time, zero-load operation, and thermal resistance of 40 °C/W (RthJA) on the HTSSOP16 exposed-pad package - all confirmed through measured junction temperature vs. fSW and efficiency curves at 400 kHz and 600 kHz.

Key Specifications

Availability

EVAL5988D is available at Aetrix Electronics and suitable for LCD TV power supplies, industrial DC-DC modules, networking router power rails, and HC LED driver development requiring stable component supply, fast design iteration, and production-ready thermal validation.

Supply support for EVAL5988D 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 40 years of automotive- and industrial-grade product development experience.

EVAL5988D belongs to ST's dedicated evaluation board portfolio for DC-DC regulators, engineered to accelerate design-in of high-current synchronous buck controllers like the L5988D into cost-sensitive, thermally constrained applications such as consumer displays and factory automation systems.

FAQ

What input and output voltage ranges does the EVAL5988D support?

The EVAL5988D board supports the full L5988D IC operating range: input voltage from 2.9 V to 18 V DC, and output voltage adjustable from 0.6 V up to the input voltage using the FB resistive divider. Measured line regulation is ≤12 mV and load regulation ≤15 mV, confirming stable regulation across these ranges under 4 A load conditions.

Does EVAL5988D include thermal performance data for the L5988D IC?

Yes - the board's documentation includes thermal characterization data: junction temperature vs. switching frequency (Figures 28–30), junction temperature vs. output voltage (Figures 31–33), and thermal impedance measurement of the evaluation board itself (Figure 23). These validate the HTSSOP16 package's 40 °C/W RthJA on ST's reference layout.

Can EVAL5988D demonstrate pre-bias startup and zero-load operation?

Yes - the board implements and verifies both features per L5988D specifications: pre-bias startup is enabled by disabling sink current during soft-start (controlled via U/O/S pin), and zero-load operation is confirmed by stable regulation with no output current, supported by <35 µA standby quiescent current (Iq st-by).

What protection functions are demonstrated on the EVAL5988D board?

The board validates all L5988D protections: UVLO with selectable thresholds for 3.3 V/5 V/12 V buses (via U/O/S pin), latched and non-latched OVP modes (Figures 9–10), constant-current protection active during soft-start and "HICCUP" mode post-soft-start, thermal shutdown (triggered at TJ ≥150 °C), and dual-switch current limiting with tracking adjustment via ILIM-ADJ pin.