ISL9440BIRZ-T

Overview

The ISL9440BIRZ-T is a quad-output synchronous buck controller from the ISL9440 series, manufactured by Renesas Electronics. It integrates three PWM controllers and one low-dropout linear regulator controller to provide multi-rail power. The device operates with a switching frequency of 300 kHz and supports an input voltage range of 4.5V to 24V. It features independent enable inputs for supply rail sequencing and includes integrated UV/OV/OC/OT protections. The component is housed in a space-conscious 32-VFQFN package with dimensions of 5mm x 5mm.

Feature Summary

• Integrates three PWM controllers and one LDO controller for multi-rail power generation
• Features internal loop compensation to minimize peripheral components
• Includes early warning function to signal data backup during input voltage drops
• Provides independent enable inputs for flexible supply rail sequencing

Applications

• Cable and satellite set-top boxes
• VoIP gateways
• Cable modems
• Home connectivity products
• Industrial control systems

Procurement Notes

Verify the specific suffix 'T' indicates tape and reel packaging configuration. Confirm current availability status as discontinuation notices may apply to this family. Ensure compatibility with existing PCB footprints for the 32-QFN package. Validate that the 300 kHz switching frequency meets system ripple requirements. Check for any recent product change notifications affecting assembly or materials.

Selection Notes

Select this component when a compact solution for four output rails is required. The integrated compensation reduces design complexity compared to discrete solutions. Consider the 300 kHz frequency for balancing efficiency and component size. Verify that the input voltage range covers the system's operational needs. Evaluate the early warning feature if system data protection during brownouts is critical.

Part Context

The ISL9440BIRZ-T belongs to the ISL9440 family of mixed-signal power management ICs. This series is designed for applications requiring multiple regulated voltages from a single controller. The B variant specifically denotes the 300 kHz switching frequency option, distinguishing it from the A variant which operates at 600 kHz. The family shares common architectural features but differs in timing characteristics.

Replacement Considerations

ISL9440AIRZ-T offers a 600 kHz switching frequency alternative within the same package. ISL9441 provides similar functionality but lacks the early warning feature. Verify pin-to-pin compatibility before substitution. Review datasheet differences regarding thermal performance and control loop stability.