Renesas ISL8126EVAL1Z

Overview

ISL8126EVAL1Z from Renesas Electronics is an evaluation board designed to demonstrate the 2-phase single-output synchronous buck regulator performance of the ISL8126 dual PWM controller IC. It delivers a preset 1.2V/50A output at 350kHz switching frequency, uses two Renesas LFPAK MOSFETs per phase and 320nH PULSE inductors, and supports remote voltage sensing and clock synchronization via JP5.

For engineers reviewing the ISL8126EVAL1Z datasheet, ISL8126EVAL1Z pinout, ISL8126EVAL1Z application, or ISL8126EVAL1Z equivalent, this board enables rapid validation of high-current, low-voltage DC-DC conversion in server VRMs, telecom power modules, and FPGA/GPU core supplies - with built-in test points for PGOOD monitoring (TP4), remote sense (TP8/TP10), and waveform capture (TP12).

Technical Context

The ISL8126EVAL1Z implements a 2-phase interleaved synchronous buck topology using the ISL8126IRZ controller, configured for single-output operation with phase interleaving to reduce input/output ripple and improve thermal distribution. It integrates dual gate drivers, current-sense amplifiers, and programmable UVLO (8V turn-off / 9V restart) via R19 (16.5kΩ) and R1 (1.82kΩ) on the EN/FF pin.

Output regulation is achieved through remote sensing (via TP8/TP10), adjustable VOUT (0.6V–2.0V via R11/R8), and precise current sharing (ISHARE pin). The board supports external clock synchronization (JP5), CLKOUT monitoring (JP3), and load transient testing up to 48A with 3A/µs slew rate using the integrated load-step circuit.

Key Specifications

Availability

ISL8126EVAL1Z is available at Aetrix Electronics and suitable for server VRM validation, telecom rectifier module development, and high-performance FPGA power system prototyping requiring stable component supply and documented reference performance.

Supply support for ISL8126EVAL1Z 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 microcontrollers, analog power, and SoC solutions for automotive, industrial, and data infrastructure applications.

The ISL8126EVAL1Z belongs to Renesas' high-current DC-DC evaluation platform family, engineered specifically to accelerate design-in of multi-phase buck regulators for AI accelerators, 5G baseband units, and enterprise computing power systems.

FAQ

What is the primary function of the ISL8126EVAL1Z evaluation board?

The ISL8126EVAL1Z evaluation board is a fully assembled hardware platform that demonstrates the 2-phase single-output synchronous buck regulator capability of the ISL8126 dual PWM controller. It provides a validated reference design for 1.2V/50A power delivery, including all critical components - MOSFETs, inductors, POSCAP output capacitors, and precision resistive programming - enabling immediate performance measurement and system integration testing without custom PCB development. The ISL8126EVAL1Z is not a standalone IC but a functional evaluation tool.

Can the output voltage of the ISL8126EVAL1Z be adjusted, and if so, how?

Yes, the ISL8126EVAL1Z output voltage can be adjusted from 0.6V to 2.0V by modifying the feedback divider resistors R11 and R8, as defined by Equation 3 in the AN1713 user's manual: R11 = [(V_OUT/V_REF) − 1] × R8, where V_REF = 0.6V. The board ships with R11 = R8 = 200Ω for the default 1.2V setting. Changing these resistors alters the voltage sensed at the FB1 pin of the ISL8126IRZ controller onboard the ISL8126EVAL1Z, directly reprogramming the regulation point.

Does the ISL8126EVAL1Z support remote voltage sensing, and how is it implemented?

Yes, the ISL8126EVAL1Z supports remote voltage sensing via dedicated test points TP8 (VSEN1−) and TP10 (VSEN1+) located near the output lugs J3/J4. These pins connect directly to the ISL8126IRZ's VSEN1+ and VSEN1− inputs, enabling accurate regulation at the load by compensating for PCB trace resistance. To activate remote sensing, R12 and R14 must be changed from 0Ω to higher values (e.g., 10Ω), and the voltage divider resistors (R11/R8) scaled accordingly - a configuration verified on the ISL8126EVAL1Z during characterization.

What test equipment is required to evaluate the ISL8126EVAL1Z performance?

Evaluating the ISL8126EVAL1Z requires a 0–22V/20A DC power supply, two electronic loads capable of sinking up to 30A each, a 100MHz quad-trace oscilloscope with low-noise probes, and digital multimeters. The board includes dedicated test points - TP12 for output waveform capture, TP4 for PGOOD logic level, and TP1/TP3 for ground and PVIN monitoring - enabling direct measurement of efficiency, line/load regulation, ripple, and transient response as documented in Figures 5–12 of AN1713. The ISL8126EVAL1Z is designed for plug-and-play validation with industry-standard lab gear.

How is input undervoltage lockout (UVLO) programmed on the ISL8126EVAL1Z?

UVLO on the ISL8126EVAL1Z is programmed using a resistor divider on the EN/FF1 pin: R19 = 16.5kΩ (upper) and R1 = 1.82kΩ (lower), resulting in a falling threshold of 8V and hysteresis of 1V (restart at 9V). This configuration follows Equations 1 and 2 from AN1713, leveraging the ISL8126's internal 0.8V reference and 30µA hysteresis current. The same divider also sets the amplitude of the internal sawtooth waveform, making UVLO tuning inseparable from PWM ramp calibration on the ISL8126EVAL1Z.