Renesas ISL91128IIN-EVKIT1Z

Overview

ISL91128IIN-EVKIT1Z from Renesas is an evaluation board kit for the ISL91128IINZ high-efficiency buck-boost regulator, designed to validate dynamic voltage scaling, I²C-controlled output regulation (1.9V–5.0V), and seamless buck/boost mode transitions in battery-powered systems. It supports 2.5V–4.35V input range, delivers up to 2.4A at 3.3V output, and features 2.5MHz switching frequency with 30µA quiescent current.

For engineers reviewing the ISL91128IIN-EVKIT1Z datasheet, ISL91128IIN-EVKIT1Z application notes, ISL91128IIN-EVKIT1Z test setup, or ISL91128IIN-EVKIT1Z compatibility with ISL91128IINZ, this kit provides validated reference design, component layout, thermal performance data, and I²C register access for rapid prototyping of Li-ion battery-powered mobile and RF power amplifier applications.

Technical Context

The ISL91128IIN-EVKIT1Z implements a complete hardware validation platform for the ISL91128IINZ buck-boost IC, featuring a 1µH inductor, 2×22µF output capacitors, and 2×10µF input capacitors matched to the IC's 2.5MHz switching frequency and 4.5A internal switches. It exposes all critical signals-including SDA, SCL, EN, FB, PVIN, VIN, LX1, LX2, VOUT, PGND, and SGND-for real-time measurement and firmware integration.

This kit enables full characterization of the ISL91128's proprietary buck-boost algorithm, including PFM/PWM transition thresholds (75mA/200mA), soft-start timing (2ms Buck / 3ms Boost), and bypass-mode operation with 6µA quiescent current-under controlled ambient conditions (-40°C to +85°C) and across the full 1.8V–5.5V input range.

Key Specifications

Availability

ISL91128IIN-EVKIT1Z is available at Aetrix Electronics and suitable for smartphone power management validation, tablet brownout-free supply design, and 4G RF power amplifier biasing requiring stable component supply, repeatable lab testing, and production-ready reference schematics.

Supply support for ISL91128IIN-EVKIT1Z 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 mixed-signal solutions for automotive, industrial, and consumer applications.

The ISL91128 product line targets advanced battery-powered devices requiring high-efficiency, dynamically reconfigurable power conversion-specifically addressing voltage droop challenges in next-generation smartphones, tablets, and wireless communication systems.

FAQ

What is the primary purpose of the ISL91128IIN-EVKIT1Z?

The ISL91128IIN-EVKIT1Z is an evaluation board kit designed exclusively to demonstrate and validate the ISL91128IINZ buck-boost regulator. It provides a fully assembled, tested platform with optimized component selection-including 1µH inductor and 2×22µF output capacitors-to verify dynamic voltage scaling, I²C register programming, buck/boost mode transitions, and thermal performance under real-world load and input conditions. The ISL91128IIN-EVKIT1Z does not function as a standalone power supply but serves as a reference for system-level integration of the ISL91128IINZ.

Does the ISL91128IIN-EVKIT1Z support I²C communication out-of-the-box?

Yes, the ISL91128IIN-EVKIT1Z includes on-board pull-up resistors for SDA and SCL lines compatible with standard 3.3V I²C buses, and exposes both pins via test points and headers. Users can immediately issue I²C commands-including output voltage changes (1.9V–5.0V), ultrasonic mode enable/disable, and soft-discharge control-to the ISL91128IINZ using any standard I²C master. The ISL91128IIN-EVKIT1Z documentation confirms full register map access per Tables 3–5 in FN8732 Rev.3.00.

Can the ISL91128IIN-EVKIT1Z be used to evaluate bypass mode operation?

Yes, the ISL91128IIN-EVKIT1Z supports full evaluation of bypass mode, which reduces quiescent current to 6µA by enabling direct conduction through high-side FETs. Bypass mode is activated via I²C register write (Bit 5 of Mode Control register), and the ISL91128IIN-EVKIT1Z's layout preserves signal integrity for accurate measurement of voltage drop, efficiency, and transient response during mode transitions-verified per Figure 10 and Section "Bypass Mode Operation" in the datasheet.

What are the key thermal characteristics validated by the ISL91128IIN-EVKIT1Z?

The ISL91128IIN-EVKIT1Z validates thermal behavior under sustained 2.4A loads, including junction temperature rise (θJA = 72°C/W), thermal shutdown activation at 155°C, and hysteresis recovery at 125°C. Its 20-ball WLCSP footprint and copper-pour ground planes replicate production thermal dissipation, enabling accurate IR imaging and thermal margin analysis-critical for smartphone and tablet designs where spatial constraints limit heatsinking options. The ISL91128IIN-EVKIT1Z allows direct correlation between measured die temperature and efficiency curves in Figures 4–7.

Is the ISL91128IIN-EVKIT1Z compatible with other members of the ISL911xx family?

No-the ISL91128IIN-EVKIT1Z is specifically configured for the ISL91128IINZ, including its 20-ball WLCSP package, I²C interface, and dynamic voltage scaling capability. It is not compatible with the ISL91127 (no I²C, no bypass mode) or ISL91127IR (QFN package). The ordering information and Table 1 in FN8732 explicitly designate ISL91128IIN-EVKIT1Z as the evaluation kit for ISL91128IINZ only, and its schematic, layout, and BOM reflect the unique pinout and feature set of that variant.