Renesas ISL8120EVAL3Z

Overview

ISL8120EVAL3Z from Renesas Electronics is an evaluation board designed to demonstrate the dual independent output and DDR memory power delivery capabilities of the ISL8120 dual-phase synchronous buck PWM controller IC. It supports 12V input, 500kHz switching frequency, and delivers 1.2V/25A per channel with preset rDS(ON)/DCR current sensing and remote voltage sensing. The board is used for performance validation in high-current CPU/GPU core and DDR memory power applications.

For engineers reviewing the ISL8120EVAL3Z datasheet, ISL8120EVAL3Z pinout, ISL8120EVAL3Z application, or ISL8120EVAL3Z equivalent, this board enables rapid characterization of transient response, efficiency, line/load regulation, start-up sequencing, and VDDQ/VTT tracking behavior - critical for server, workstation, and high-performance embedded power design.

Technical Context

The ISL8120EVAL3Z implements the ISL8120IRZ (32-pin QFN) as its core controller, configured for dual independent 1.2V/25A outputs using external Renesas RJK0305DPB (30A) and RJK0301DPB (60A) LFPAK MOSFETs, 320nH PULSE inductors, and SANYO POSCAP 470µF/2.5V output capacitors. It includes full remote sense capability via TP19/TP26/TP28/TP31 test points and supports both DCR and rDS(ON) current sensing modes via JP7/JP8 jumpers.

Board-level features include programmable UVLO (via R129/R135 = 13.7k/4.42k for 3.38V fall / 4.42V rise), on-board transient load injection (TP22/TP30), clock synchronization (TP27), and DDR-specific configuration where Channel 1 (VDDQ) feeds REFIN to Channel 2 (VTT) for tracking startup. Preset output voltage is set by R116/R119 (100Ω) for 1.2V, per VOUT = 0.6V × (1 + R119/R116).

Key Specifications

Availability

ISL8120EVAL3Z is available at Aetrix Electronics and suitable for high-current CPU/GPU core power validation, DDR memory subsystem evaluation, and multi-rail server PSU development requiring stable component supply and repeatable lab characterization.

Supply support for ISL8120EVAL3Z 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 Corporation is a global semiconductor manufacturer specializing in microcontrollers, analog, power management, and timing solutions for automotive, industrial, and computing markets.

The ISL8120EVAL3Z belongs to Renesas' high-performance power management evaluation platform family, designed specifically to accelerate adoption of multi-phase buck controllers in data center, AI accelerator, and high-end client platform power designs.

FAQ

What is the primary function of the ISL8120EVAL3Z evaluation board?

The ISL8120EVAL3Z evaluation board is a hardware platform built around the ISL8120IRZ dual-phase PWM controller to demonstrate and validate dual independent output operation and DDR memory power delivery (VDDQ/VTT tracking). It provides fully assembled, tested circuitry with test points, jumpers, and presets enabling immediate efficiency, transient, regulation, and sequencing measurements without custom PCB design. The ISL8120EVAL3Z supports 12V input and delivers 1.2V/25A per channel under real-world load conditions.

How is output voltage programmed on the ISL8120EVAL3Z?

Output voltage on the ISL8120EVAL3Z is set by the feedback divider network connected to FB1/FB2 pins of the ISL8120IRZ. With R116 and R119 both at 100Ω, the board delivers 1.2V per channel using the formula VOUT = 0.6V × (1 + R119/R116). To adjust VOUT1 or VOUT2 between 0.6V and 3.0V, users replace either resistor per Equation 1 in AN1528. The ISL8120EVAL3Z does not support dynamic voltage scaling - changes require physical resistor replacement and revalidation.

Can the ISL8120EVAL3Z be used for DDR3 or DDR4 memory power applications?

Yes, the ISL8120EVAL3Z supports DDR3 memory power delivery in VDDQ/VTT tracking mode. By connecting Channel 1's output to the REFIN pin (Pin 7) of Channel 2 and configuring EN/FF timing with RC filters, the board replicates the typical DDR3 startup sequence where VTT follows VDDQ. Test waveforms in Figures 18–19 of AN1528 confirm proper tracking behavior. While optimized for DDR3, the ISL8120EVAL3Z can be adapted for DDR4 with updated resistor dividers and timing adjustments - but no factory validation for DDR4 is provided.

What current sensing methods does the ISL8120EVAL3Z support?

The ISL8120EVAL3Z defaults to DCR current sensing using the inductor's parasitic resistance and an RC filter network. To switch to rDS(ON) sensing - required for outputs above 3V due to common-mode voltage limits - users must remove R102/R96, install 0Ω resistors at R107/R95, and short JP7. This reconfigures the ISL8120IRZ's differential amplifiers to measure high-side MOSFET on-resistance. The ISL8120EVAL3Z includes all necessary footprints and jumpers for either method, verified in Section 4 of AN1528.

Does the ISL8120EVAL3Z include remote voltage sensing capability?

Yes, the ISL8120EVAL3Z includes full remote sense capability for both output channels via dedicated test points: TP19/TP26 (VSEN_REM2−/+), TP28/TP31 (VSEN_REM1−/+). These connect directly to the ISL8120IRZ's VSEN1± and VSEN2± pins. To enable remote sensing, users must increase R109/R120/R155/R161 from 0Ω to 10Ω and scale the corresponding voltage divider resistors (e.g., to 1kΩ) to maintain proper feedback gain - as specified in Section 3 of AN1528. This ensures accurate regulation at the load, compensating for PCB trace IR drop.