Renesas ISL81805EVAL1Z

Overview

ISL81805EVAL1Z from Renesas Electronics is a dual-phase evaluation board designed to validate the ISL81805 80V high-voltage synchronous boost controller in high-output-voltage applications. It delivers 48V at up to 5A output with 200kHz switching frequency, integrated UV/OV/OC/OT protection, and programmable soft-start. The board supports DEM/PWM mode selection, input/output average OCP, and pre-bias start-up - enabling rapid prototyping of industrial and telecom power supplies.

For engineers reviewing the ISL81805EVAL1Z datasheet, ISL81805EVAL1Z pinout, ISL81805EVAL1Z application, or ISL81805EVAL1Z equivalent, this evaluation platform provides full access to test points (TP1–TP24), jumper-configurable operation modes (PWM/DEM, CC/HICCUP), and validated thermal performance at 5A continuous load without forced airflow.

Technical Context

The ISL81805EVAL1Z implements a dual-phase, non-synchronous boost topology using the ISL81805 TQFN-32 controller IC. It features independent enable control, external soft-start capacitor (C22), and phase-lock loop (PLL) synchronization capability. Input voltage range is 9V–36V, regulated to 48V output via two parallel boost stages with discrete N-channel MOSFETs (Infineon BSC070N10NS5ATMA1).

Protection functions include input average overcurrent (set to ≥17.6A), output overvoltage (OVP), under-voltage (UVP), thermal shutdown (OTP), and hiccup-mode current limiting. The board uses 10µH power inductors (Wurth 74439370100), 440µF electrolytic + 18.8µF MLCC output capacitance per phase, and 220µF input bulk capacitors with ceramic bypassing.

Key Specifications

Availability

ISL81805EVAL1Z is available at Aetrix Electronics and suitable for industrial power supply validation, telecom rectifier development, and high-voltage DC-DC converter design requiring stable component supply, traceable sourcing, and long-term evaluation board continuity.

Supply support for ISL81805EVAL1Z 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 leader delivering high-performance analog, power, and embedded processing solutions for automotive, industrial, and infrastructure markets.

The ISL81805EVAL1Z belongs to Renesas' high-voltage DC-DC controller evaluation platform family, engineered to accelerate adoption of the ISL81805 dual-phase boost controller in 48V intermediate bus, battery backup, and industrial power systems.

FAQ

What is the primary function of the ISL81805EVAL1Z evaluation board?

The ISL81805EVAL1Z evaluation board is a fully assembled, tested platform for evaluating the ISL81805 80V dual-phase synchronous boost controller. It enables engineers to validate performance metrics-including 48V/5A output regulation, 200kHz switching, DEM/PWM mode behavior, and protection features-without designing custom hardware. The board integrates all necessary power components, test points, and configuration jumpers to streamline lab testing and system integration of the ISL81805 controller IC.

Can the ISL81805EVAL1Z be used to evaluate different output voltages beyond 48V?

Yes, the ISL81805EVAL1Z can be reconfigured for output voltages other than 48V by modifying the feedback resistor divider network (R1 and R12). The ISL81805 controller supports output voltages from 0.8V up to the maximum determined by external component ratings and layout constraints. However, changing the output voltage requires recalculating feedback resistors, verifying MOSFET voltage stress, and validating inductor saturation margins - all documented in the ISL81805EVAL1Z Evaluation Board Manual Section 2.5.3.

How is overcurrent protection implemented on the ISL81805EVAL1Z?

The ISL81805EVAL1Z implements dual-level overcurrent protection: first-level pulse-by-pulse peak current limiting (via sense resistor R14/R22) and second-level hiccup-mode or constant-current OCP (selected via jumper J7). Input average OCP is set to ≥17.6A at room temperature using the RIM resistor network. These protections are enabled by the underlying ISL81805 controller and verified across the full operating range - ensuring robust fault handling during transient overload and short-circuit conditions.

Does the ISL81805EVAL1Z support synchronization with external clock signals?

Yes, the ISL81805EVAL1Z supports external clock synchronization via the PLL input (CLKIN pin on U1). The ISL81805 controller includes a phase-lock loop that allows the board's switching frequency to be locked to an external clock source - enabling noise-sensitive multi-rail systems to avoid beat frequencies and simplify EMI filtering. This functionality is accessible through dedicated test points and is detailed in Section 2.5.16 of the evaluation board manual.

What thermal performance can be expected from the ISL81805EVAL1Z at full 5A load?

The ISL81805EVAL1Z delivers 5A continuously at 48V output without forced airflow under ambient room temperature (25°C) conditions. Thermal performance is sustained by optimized PCB layout - including dedicated power ground planes, short high-current loops, and thermal vias beneath MOSFETs and inductors. At elevated ambient temperatures (>60°C), airflow is recommended to maintain safe junction temperatures for the Infineon BSC070N10NS5ATMA1 FETs and Wurth 74439370100 inductors.