Renesas ISLA118P50IR72EV1Z

Overview

ISLA118P50IR72EV1Z from Intersil is a ZVS full-bridge DC-DC power supply evaluation board featuring the ISL6754 PWM controller, supporting 500W+ off-line applications with synchronous rectifier drive and average current limiting. It implements a current-doubler secondary topology, operates at 228 kHz switching frequency, and delivers up to 12 V / 60 A output with ±0.6 V FB regulation reference.

For engineers reviewing the ISLA118P50IR72EV1Z datasheet, ISLA118P50IR72EV1Z pinout, ISLA118P50IR72EV1Z application, or ISLA118P50IR72EV1Z equivalent, this board enables rapid validation of ZVS resonant full-bridge designs requiring precise voltage/current dual-loop control, opto-isolated feedback, and SR timing optimization in high-efficiency server PSU and telecom rectifier systems.

Technical Context

The ISLA118P50IR72EV1Z integrates the ISL6754 controller with two independent error amplifiers-one for voltage regulation (FB pin, −0.6 V reference) and one for average current limiting (IOUT pin, 3.085 V at 60 A). It uses external op-amp compensation (EL5111) and linear opto-isolation (PS2701) to bridge primary/secondary boundaries while maintaining stable loop dynamics across input range (330–450 V_DC) and load transients.

Design includes slope compensation via CT pin (VCT.s = 0.966 V/μs), pulse-by-pulse current limit (1 V threshold), and negative transient clamping on FB to prevent −0.3 V undershoot during mode transition. The board supports dead-time adjustment (RTD = 6.65 kΩ) and provides dedicated signals for synchronous rectifier gate drive and diode emulation.

Key Specifications

Availability

ISLA118P50IR72EV1Z is available at Aetrix Electronics and suitable for high-efficiency AC-DC power supplies, telecom rectifiers, and server PSUs requiring stable component supply, fast design validation, and production-ready ZVS control architecture.

Supply support for ISLA118P50IR72EV1Z 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

Intersil (now part of Renesas Electronics) is a semiconductor company specializing in high-performance analog and power management ICs for industrial, computing, and communications markets.

The ISLA118P50IR72EV1Z belongs to Intersil's ZVS full-bridge evaluation platform family, designed to accelerate development of high-efficiency, high-power-density DC-DC converters targeting 500W+ offline applications with strict thermal and efficiency requirements.

FAQ

What is the primary function of the ISLA118P50IR72EV1Z evaluation board?

The ISLA118P50IR72EV1Z is a plug-in daughter card that implements a ZVS full-bridge DC-DC power supply controller using the ISL6754 IC. Its primary function is to enable rapid prototyping and validation of high-efficiency, 500W+ off-line power supplies with synchronous rectification, dual-loop (voltage + average current) regulation, and opto-isolated feedback. It is not a standalone power supply but a control card intended for integration with customer-provided power stages.

Does the ISLA118P50IR72EV1Z support both voltage and current regulation modes?

Yes, the ISLA118P50IR72EV1Z supports seamless transition between voltage and current regulation modes via the ISL6754's dual error amplifiers. The voltage amplifier regulates output voltage below 60 A; above that, the average current amplifier takes control using the IOUT pin signal. The OR-ing diode network ensures only one amplifier drives the PWM comparator at any time, enabling independent compensation of each loop.

What is the role of the FB pin on the ISLA118P50IR72EV1Z, and why is a negative clamp required?

The FB pin on the ISLA118P50IR72EV1Z serves as the inverting input of the voltage error amplifier and has a −0.6 V reference. During transition from voltage to current regulation, the voltage amplifier output slews negatively, causing a transient undershoot on FB. Because the absolute minimum rating is −0.3 V, a negative clamp (e.g., Schottky diode to −0.3 V rail) is mandatory to prevent damage or instability-this requirement is explicitly documented in AN1619 for the ISLA118P50IR72EV1Z design.

Can the ISLA118P50IR72EV1Z be used with center-tap rectification topologies?

No-the ISLA118P50IR72EV1Z is specifically designed and validated for current-doubler secondary topology, as confirmed in AN1619 Section "About this Analysis". The application note explicitly states calculations and compensation methods do not apply to center-tap rectification, and users must derive their own design equations if adapting the ISLA118P50IR72EV1Z for CT configurations.

What are the key external components required to operate the ISLA118P50IR72EV1Z?

To operate the ISLA118P50IR72EV1Z, users must provide: (1) a full-bridge power stage with transformer (Nt = 13, Lpri = 3200 μH), (2) current-sensing transformer (Nct = 50), (3) synchronous rectifier MOSFETs with gate drive circuitry, (4) output LC filter (Lind = 3.3 μH, Cout with Resr), and (5) isolated 5 V bias supply for the secondary-side EL5111 op-amp and PS2701 optocoupler. No onboard power conversion components are included.