Renesas ISL6740EVAL3Z

Overview

ISL6740EVAL3Z from Renesas Electronics is an evaluation board implementing a 48V-to-±12V, 3.3V and 1.5V isolated power supply reference design. It uses the ISL6740 double-ended voltage-mode controller in half-bridge topology for primary isolation and the ISL6402 dual PWM controller in synchronous buck topology for secondary regulation. The board delivers 3.3V ±1% @ 4A, 1.5V ±1% @ 7A, and ±12V with typical tolerance of +3.5%/−10% @ 1.5A each, achieving 86.8–90.3% full-load efficiency across 36–72V input.

For engineers reviewing the ISL6740EVAL3Z datasheet, ISL6740EVAL3Z pinout, ISL6740EVAL3Z application, or ISL6740EVAL3Z equivalent, this board serves as a validated hardware platform to evaluate multi-rail isolated DC/DC conversion architecture, validate thermal performance under forced-air cooling (100–500LFM), assess transient response on 1.5V/3.3V rails, and verify ROHS-compliant layout implementation for industrial telecom power systems.

Technical Context

The ISL6740EVAL3Z implements a two-stage architecture: a primary isolated forward/half-bridge stage using the ISL6740 controller driving HIP2101 half-bridge drivers and FDS3672 MOSFETs, followed by secondary non-isolated synchronous buck stages using ISL6402 to generate 3.3V and 1.5V from the +12V rail. Feedback is split-individual voltage loops regulate 1.5V and 3.3V outputs, while ±12V shares a single feedback path, resulting in coupled regulation behavior.

Thermal management is characterized across ambient temperatures (30–80°C) and airflow (100–500LFM), with hottest component temperature tracked at both 36V and 72V input. Ripple and noise are measured at ≤80mVP-P (48V input, all outputs fully loaded), and start-up overshoot on +12V reaches up to 1V depending on input voltage.

Key Specifications

Availability

ISL6740EVAL3Z is available at Aetrix Electronics and suitable for telecom power system validation, industrial embedded power architecture prototyping, and multi-output isolated DC/DC design verification requiring stable component supply and documented thermal/efficiency benchmarks.

Supply support for ISL6740EVAL3Z 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

Renesas Electronics is a global semiconductor manufacturer delivering microcontrollers, analog, power, and SoC solutions for automotive, industrial, and infrastructure applications.

The ISL6740EVAL3Z belongs to Renesas' power management evaluation platform family, designed to accelerate development of high-efficiency, multi-rail isolated power supplies for telecom, server, and industrial equipment.

FAQ

What is the primary function of the ISL6740EVAL3Z?

The ISL6740EVAL3Z is a reference evaluation board-not a component-that demonstrates a complete 48V-input isolated power supply generating ±12V, 3.3V, and 1.5V outputs. It integrates the ISL6740 double-ended controller and ISL6402 dual PWM controller to validate system-level performance, including efficiency, regulation, thermal behavior, and transient response under real-world loading conditions. The ISL6740EVAL3Z enables rapid hardware assessment before custom design spin.

Which controllers are used on the ISL6740EVAL3Z board?

The ISL6740EVAL3Z board uses two key Renesas controllers: the ISL6740IBZ double-ended voltage-mode controller for the primary isolated half-bridge stage, and the ISL6402IVZ dual synchronous buck PWM controller for regulating the 3.3V and 1.5V outputs from the +12V rail. These ICs are explicitly listed in the bill of materials (Table 1) and schematics of the ISL6740EVAL3Z User Guide AN1127 Rev 2.00.

Does the ISL6740EVAL3Z support ROHS compliance?

Yes, the ISL6740EVAL3Z board is explicitly designed and documented as ROHS-compliant per the AN1127 User Guide (Page 3). All components listed in Table 1-including MOSFETs (FDS3672-T, HAT2116H-EL-E), controllers (ISL6740IBZ, ISL6402IVZ), magnetics (Midcom 31660-LF1, Pulse P8205NL), and passives-are marked "ROHS" in the BOM, and the board layout adheres to lead-free assembly standards.

What are the measured efficiency and thermal limits of the ISL6740EVAL3Z?

The ISL6740EVAL3Z achieves 86.8% efficiency at 72V input and 90.3% at 36V input under full proportional load. Thermal characterization shows the hottest component reaches ≤110°C at 80°C ambient with 300LFM airflow (Figure 15), and worst-case temperature rise remains within safe operating margins across 100–500LFM airflow rates per Figures 13 and 14 - confirming suitability for enclosed industrial environments with active cooling.

Can the ISL6740EVAL3Z be used to evaluate LDO implementation?

Yes, the ISL6740EVAL3Z provides dedicated pads to implement an optional LDO, with the ISL6402 configured as its controller per the User Guide (Page 1). This flexibility allows engineers to extend the 3.3V or 1.5V rail with low-noise post-regulation - a capability verified in the schematic (U5 FB1/VOUT1 connections) and explicitly called out in the functional description of the ISL6740EVAL3Z reference design.