STMicroelectronics STEVAL-L6983IV1

Overview

STEVAL-L6983IV1 from STMicroelectronics is an evaluation board based on the L6983I 38 V, 10 W synchronous iso-buck DC-DC converter IC for isolated power supply applications. It implements primary-side regulation with no optocoupler, supports 4–38 V input, delivers up to 10 W isolated unregulated output, and includes embedded transformer, integrated EMI filter, and programmable 200 kHz–1 MHz switching frequency.

For engineers reviewing the STEVAL-L6983IV1 datasheet, STEVAL-L6983IV1 pinout, STEVAL-L6983IV1 application, or STEVAL-L6983IV1 equivalent, this board enables rapid validation of iso-buck topology in industrial metering, motor drive auxiliary supplies, and isolated sensor interface power rails under real PCB layout and thermal conditions.

Technical Context

The board implements a peak current mode controlled iso-buck converter using the L6983I IC, operating in forced PWM with 390 ns blanking time to suppress leakage inductance oscillations. Primary-side regulation eliminates optocoupler dependency while enabling accurate primary output adjustment and robust secondary-side energy transfer via –4.5 A reverse current sink capability during soft-start.

It integrates internal compensation, QFN-16 3×3 mm packaging, and supports external synchronization and spread-spectrum modulation. The post-regulation layout (unpopulated) allows dual-voltage generation (e.g., isolated + LDO-stabilized outputs), and the PGOOD open-collector signal monitors FB voltage for system sequencing.

Key Specifications

Availability

STEVAL-L6983IV1 is available at Aetrix Electronics and suitable for industrial power supply design, smart metering subsystems, motor drive auxiliary bias rails, and isolated analog front-end power delivery requiring stable component supply and fast prototyping turnaround.

Supply support for STEVAL-L6983IV1 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 headquartered in Geneva, designing and manufacturing microcontrollers, power ICs, sensors, and analog devices for industrial, automotive, and consumer applications.

The L6983I product line targets compact, high-reliability isolated DC-DC conversion in space-constrained industrial equipment where optocoupler-free regulation, low EMI, and primary-side control are essential design requirements.

FAQ

What is the purpose of the unpopulated post-regulation section on the STEVAL-L6983IV1 PCB?

The bottom-side post-regulation layout supports adding an external LDO (e.g., LDH40) or shunt regulator (e.g., TL431) to generate a second, tightly regulated output from the main isolated unregulated rail. Components are not mounted by default, allowing users to evaluate regulation trade-offs without soldering constraints.

Does the STEVAL-L6983IV1 require an optocoupler for feedback isolation?

No. The board uses the L6983I's primary-side regulation architecture, which senses reflected output voltage across the transformer turns ratio and eliminates the need for optocouplers or secondary-side sensing circuitry-reducing cost, size, and failure points.

How is synchronization implemented on this evaluation board?

Synchronization is supported via the EN/CLKIN pin (Pin 4 of U1). When driven with an external clock signal, the L6983I locks its switching frequency and phase to that source, enabling noise reduction in multi-rail systems and deterministic EMI behavior during EMC testing.

What protection features are implemented on the STEVAL-L6983IV1?

The board inherits L6983I's full protection suite: pulse-by-pulse current limiting on both high- and low-side switches, thermal shutdown, primary reverse current limit (protecting secondary against short-circuit), and PGOOD monitoring of FB voltage for upstream system sequencing and fault detection.