Renesas ISL85415EVAL1Z

Overview

The ISL85415EVAL1Z from Renesas Electronics is an evaluation kit designed to demonstrate the performance of the ISL85415 wide-input-voltage (3V–36V), 500mA synchronous buck regulator in point-of-load applications. It features a fixed 3.3V output (adjustable to 0.6V–15V), 500kHz default switching frequency, and supports both PFM and forced PWM light-load operation.

For engineers reviewing the ISL85415EVAL1Z datasheet, ISL85415EVAL1Z pinout, ISL85415EVAL1Z application, or ISL85415EVAL1Z equivalent, this board enables rapid validation of efficiency, load regulation, startup/shutdown behavior, and SYNC/EN/PG functionality across input voltages up to 36V and output currents up to 500mA.

Technical Context

The ISL85415EVAL1Z implements the ISL85415 IC in a fully assembled, tested configuration with selectable operating modes: PFM for ultra-low quiescent current at light loads, or forced PWM for predictable frequency and reduced output ripple. The board includes on-board jumpers (S1, S2) and resistor options (R6, R10, R12, R15) to configure enable/disable, mode selection, frequency programming (300kHz–2MHz), and soft-start source.

It integrates all critical external components-including 22µH power inductor (DR73-220-R), dual 22µF output capacitors (ECJ-DV50J226M), feedback resistors (R1 = 90.9kΩ, R2 = 20kΩ for 3.3V), and FS/SYNC/EN/PG signal access points-enabling immediate bench evaluation without component sourcing or layout design.

Key Specifications

Availability

ISL85415EVAL1Z is available at Aetrix Electronics and suitable for industrial power supply validation, embedded system PoL prototyping, and automotive subsystem voltage rail testing requiring stable component supply and documented reference performance.

Supply support for ISL85415EVAL1Z 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, infrastructure, and IoT applications.

The ISL85415EVAL1Z belongs to Renesas' high-efficiency DC/DC evaluation kit portfolio, engineered specifically to accelerate adoption of wide-VIN buck regulators in space-constrained, thermally demanding point-of-load designs.

FAQ

What is the purpose of the ISL85415EVAL1Z evaluation kit?

The ISL85415EVAL1Z is a fully assembled demonstration platform for the ISL85415 synchronous buck regulator. It allows engineers to validate key performance metrics-including efficiency, load regulation, transient response, and mode-switching behavior-without designing a custom PCB. The ISL85415EVAL1Z supports input voltages from 3V to 36V and delivers up to 500mA at user-adjustable output voltages from 0.6V to 15V.

Can the output voltage of the ISL85415EVAL1Z be changed from the default 3.3V?

Yes, the ISL85415EVAL1Z output voltage is adjustable from 0.6V to 15V by modifying the feedback resistor divider (R1 and R2). The default 3.3V setting uses R1 = 90.9kΩ and R2 = 20kΩ. For other voltages, Equation 1 in the AN1859 manual must be applied, and component values (including inductor and compensation) may require adjustment per Table 1-especially below 1.8V, where minimum on-time constraints necessitate frequency and compensation changes.

How do I configure the ISL85415EVAL1Z for forced PWM versus PFM operation?

The ISL85415EVAL1Z uses S2 to select between PFM and forced PWM modes: S2 in "PFM" position ties the SYNC pin to GND, enabling discontinuous conduction mode for lowest quiescent current; S2 in "PWM" position connects SYNC to VCC via R6 = 200kΩ, enforcing continuous conduction and fixed-frequency operation. This configuration directly controls the ISL85415's internal mode logic and is verified in Figures 25–27 of AN1859.

Does the ISL85415EVAL1Z support external clock synchronization?

Yes, the ISL85415EVAL1Z provides direct access to the SYNC pin (test point P7) for external clock injection. When driven with a clean TTL/CMOS clock signal within the 300kHz–2MHz range, the ISL85415 synchronizes its switching to that source-eliminating beat frequencies in multi-rail systems. Default configuration uses R6 = 200kΩ to VCC, disabling sync and enabling internal oscillator control.

What test equipment is required to evaluate the ISL85415EVAL1Z?

Per AN1859 Rev 4.00, recommended equipment includes a 0–50V/2A DC power supply, electronic load capable of sinking ≥1.5A, 100MHz quad-trace oscilloscope, digital multimeters, and signal generator. Critical measurements-such as efficiency curves (Figures 5–10), load transients (Figures 25–26), and startup/shutdown waveforms (Figures 17–19)-require simultaneous probing of VIN, VOUT, LX, IL, EN, and PG signals using the provided test points (J1, J2, P1–P10).