Renesas ISL8088EVAL1Z

Overview

ISL8088EVAL1Z from Renesas Electronics is an evaluation board designed to demonstrate the ISL8088 dual-channel synchronous buck regulator, delivering 800mA per channel at preset outputs of 2.5V (VOUT1) and 1.8V (VOUT2), operating from a 2.75V–5.5V input, with 2.25MHz switching frequency and 97% peak efficiency for Point-of-Load power delivery in compact embedded systems.

For engineers reviewing the ISL8088EVAL1Z datasheet, ISL8088EVAL1Z pinout, ISL8088EVAL1Z application, or ISL8088EVAL1Z equivalent, this board enables rapid validation of dual-output low-quiescent-current DC/DC conversion, PFM/PWM mode selection, external synchronization up to 4MHz, and pre-biased start-up behavior under real load conditions.

Technical Context

The ISL8088EVAL1Z implements the ISL8088IRZ - a dual 10-lead DFN (3mm × 3mm) synchronous buck controller - with independent enable inputs (EN1/EN2), dedicated PG output, SYNC pin for mode control or external clock injection, and internal current-mode compensation. Each channel supports 100% duty cycle operation and soft-start/soft-stop sequencing.

It integrates two complete buck converter stages: each with integrated high-side/low-side MOSFETs, 2.2µH power inductors (L1/L2), 10µF output capacitors (C1/C2/C4), and precision feedback resistive dividers (R2/R3 for VOUT1; R5/R6 for VOUT2) set to deliver 2.5V and 1.8V respectively, adjustable down to 0.6V via resistor reconfiguration.

Key Specifications

Availability

ISL8088EVAL1Z is available at Aetrix Electronics and suitable for Point-of-Load power design, dual-rail microcontroller/microprocessor supply, and low-power industrial sensor node development requiring stable component supply and fast evaluation turnaround.

Supply support for ISL8088EVAL1Z 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 IoT applications, with strong heritage in high-efficiency power management.

The ISL8088EVAL1Z belongs to Renesas' legacy Intersil analog power evaluation portfolio, specifically engineered to accelerate adoption of dual-output, low-IQ synchronous buck regulators in space-constrained, battery-sensitive embedded systems.

FAQ

What is the primary purpose of the ISL8088EVAL1Z evaluation board?

The ISL8088EVAL1Z evaluation board is designed exclusively to demonstrate and validate the performance of the ISL8088 dual-channel synchronous buck regulator IC. It provides a fully assembled, tested platform with preset 2.5V and 1.8V outputs, enabling engineers to quickly assess efficiency, transient response, PFM/PWM mode behavior, and synchronization capability without custom PCB design. The ISL8088EVAL1Z includes all necessary passive components, test points, and switch controls for functional verification across its full 2.75V–5.5V input range.

Can the output voltages on the ISL8088EVAL1Z be adjusted, and how?

Yes, both VOUT1 and VOUT2 on the ISL8088EVAL1Z are adjustable from 0.6V to 3.3V using external feedback resistors. The board ships with R2 = 316kΩ and R3 = 100kΩ for 2.5V on Channel 1, and R5 = 200kΩ and R6 = 100kΩ for 1.8V on Channel 2. To change voltage, replace R2 or R5 per Equation 1 in AN1492 Rev 2.00: VOUT = 0.6V × (1 + R2/R3). For 0.6V output, R3 is omitted and R2 shorted. The ISL8088EVAL1Z schematic and BOM confirm these resistor locations and values.

How does the ISL8088EVAL1Z support different operating modes (PFM vs. PWM)?

The ISL8088EVAL1Z supports three operational modes via the SYNC pin and SW1 toggle switch. Connecting SYNC to VIN or logic high enables PFM mode for ultra-low quiescent current (30µA); grounding SYNC forces continuous PWM mode; and applying an external clock signal (≤4MHz, negative-edge triggered) enables synchronization. SW1 (labeled PWM/PFM) provides manual override, with position "1" selecting fixed-frequency PWM and position "3" selecting forced PFM. This flexibility allows direct comparison of light-load efficiency and noise performance using the ISL8088EVAL1Z.

Does the ISL8088EVAL1Z include protection features, and how are they verified?

Yes, the ISL8088EVAL1Z demonstrates key protections inherent to the ISL8088IC: over-temperature shutdown, peak current limiting, and power-good (PG) signaling with 1ms delay. The PG pin is routed to a test point and drives an LED (D2) when both outputs are within ±3% regulation. Thermal protection is validated by monitoring die temperature rise under sustained 800mA load per channel; current limiting is observable via inductor current waveform clipping on an oscilloscope. These behaviors are documented in the ISL8088EVAL1Z user manual AN1492.

What test equipment is required to evaluate the ISL8088EVAL1Z effectively?

To fully evaluate the ISL8088EVAL1Z, Renesas recommends a 0–10V/3A DC power supply (or 5V battery), electronic loads capable of sinking ≥3A total, a 100MHz quad-trace oscilloscope for voltage/current/transient analysis, digital multimeters for DC accuracy checks, and a signal generator for SYNC pin synchronization tests. All critical nodes - VIN, VOUT1/VOUT2, PG, EN1/EN2, SYNC, LX1/LX2 - are accessible via 0.1"-spaced mini test points (KEYSTONE 5000/5001), enabling non-invasive probing without soldering. The ISL8088EVAL1Z layout and test setup are detailed in AN1492 Rev 2.00.