Renesas ISL9440EVAL2Z

Overview

ISL9440EVAL2Z from Intersil (now Renesas) is an evaluation board for the ISL9440 triple synchronous buck + linear controller IC, designed to validate multi-rail power delivery in set-top boxes, VoIP gateways, and cable modems. It supports 300kHz PWM operation, 0.8V–5V programmable outputs, 180° out-of-phase switching, integrated early warning, and RST signaling - all implemented on a 5mm×5mm QFN-32 platform.

For engineers reviewing the ISL9440EVAL2Z datasheet, ISL9440EVAL2Z test setup, ISL9440EVAL2Z application circuit, or ISL9440EVAL2Z compatible controllers, this board enables rapid validation of input ripple reduction, rail sequencing, PGOOD/RST timing, and adaptive dead-time gate drive performance under real load conditions with IRF7907 MOSFETs and standard ceramic output capacitors.

Technical Context

The ISL9440EVAL2Z implements the ISL9440 IC's full feature set: three independent 300kHz current-mode synchronous buck controllers with 180°/0°/180° phase alignment, one LDO-based linear regulator (G4), internal 5V VCC_5V LDO, and early-warning monitoring of VIN. It validates critical timing relationships - including PGOOD falling within 100µs of VIN drop below 5.55V and RST asserting 5.5µs later - using discrete feedback dividers, OCSET resistors, and boot capacitor networks.

Board-level design reflects the IC's architecture: PHASE1/2/3 nodes connect directly to inductor-LGATE-UGATE junctions; ISEN1/2/3 sense lower-FET rDS(ON); FB1–FB3 and LDOFB accept resistor dividers; EN1–EN3 support independent rail enable sequencing; and PGND/SGND separation maintains signal integrity during high di/dt transients.

Key Specifications

Availability

ISL9440EVAL2Z is available at Aetrix Electronics and suitable for satellite set-top box development, VoIP gateway qualification, and cable modem power architecture validation requiring stable component supply and pre-validated reference designs.

Supply support for ISL9440EVAL2Z 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 (acquired Intersil in 2017) is a global semiconductor leader delivering microcontrollers, analog, power, and SoC solutions for automotive, industrial, and communications infrastructure.

The ISL9440EVAL2Z belongs to Renesas' power management evaluation platform family, engineered specifically to accelerate design-in of multi-output DC-DC controllers for home connectivity and broadband access equipment.

FAQ

What is the primary function of the ISL9440EVAL2Z evaluation board?

The ISL9440EVAL2Z evaluation board is a fully assembled and tested platform for validating the ISL9440 triple synchronous buck + linear controller IC. It demonstrates 300kHz operation, 180° out-of-phase switching across two channels, early-warning detection on VIN, coordinated PGOOD/RST timing, and independent rail enable sequencing - all using production-grade components like IRF7907 MOSFETs and standard ceramic capacitors. The ISL9440EVAL2Z enables immediate lab testing without custom PCB design.

Does the ISL9440EVAL2Z support both ISL9440 and ISL9440A IC variants?

No. The ISL9440EVAL2Z is specifically configured for the ISL9440 IC, which operates at 300kHz and includes early-warning functionality. It is not optimized for the ISL9440A (600kHz, same early-warning) or ISL9441 (300kHz, no early-warning). Component values - including OCSET resistors, feedback dividers, and inductors - are tuned to ISL9440's electrical characteristics and timing requirements as defined in FN6383 Rev 2.00.

How does the ISL9440EVAL2Z demonstrate input ripple reduction?

The ISL9440EVAL2Z implements the ISL9440's 180° out-of-phase switching between Channel 1 and Channel 2, with Channel 3 aligned to Channel 1. This phase relationship ensures instantaneous input current peaks do not overlap, reducing RMS input ripple current by up to 30% compared to in-phase operation. Measured waveforms on the board (e.g., Figure 9 and Figure 13 in FN6383) confirm low-voltage AC-coupled ripple across VOUT rails and reduced transient-induced noise on VIN.

What power supply configurations does the ISL9440EVAL2Z support?

The ISL9440EVAL2Z supports two main input configurations: (1) 5.6V–24V applied to the VIN pin, powering the internal 5V VCC_5V LDO; or (2) 5V±10% applied to the VCC_5V pin, with VIN tied externally - required for 5V-input applications to avoid false early-warning triggers. Both configurations are validated per datasheet Note 5 and Figure 4/5 typical application schematics.

Can the ISL9440EVAL2Z be used to evaluate the linear regulator (G4) output?

Yes. The ISL9440EVAL2Z includes a fully functional linear regulator stage driving G4, configured for +3.3V/500mA output using external PNP transistor Q4 and feedback resistors R10/R11. It validates LDOFB loop stability, dropout behavior under load, and coordination with PWM rails - including PGOOD assertion if VOUT4 falls below 75% of nominal. Performance curves (e.g., Figure 2–7) include LDO regulation and efficiency data captured on this board.