Renesas ISL65426IRZA-T

Overview

ISL65426IRZA-T from Renesas (formerly Intersil) is a monolithic dual synchronous buck regulator with integrated MOSFETs, delivering up to 6A total output current across two independently controlled channels. It operates from 3V–5.5V input, supports 1V–4.0V adjustable or VID-programmable outputs, and switches at a fixed 1MHz frequency with 180° out-of-phase PWMs to reduce input ripple. It powers FPGA core/I/O rails in compact embedded systems.

For engineers reviewing the ISL65426IRZA-T datasheet, ISL65426IRZA-T pinout, ISL65426IRZA-T application, or ISL65426IRZA-T equivalent, key selection considerations include its user-partitionable 6×1A power blocks, independent soft-start sequencing via EN1/EN2/EN, ±1% reference accuracy, thermal/overcurrent/undervoltage protection, and QFN-50 (5×10 mm) package compatibility with all-ceramic designs.

Technical Context

The ISL65426IRZA-T implements current-mode control with integrated compensation and a fixed 1MHz oscillator (±20% tolerance), enabling stable all-ceramic solutions and excellent transient response. Its unique architecture partitions six 1A power blocks-two master (LX1/LX2 assigned per channel) and four floating (LX3–LX6)-into four validated configurations (e.g., 3A:3A, 4A:2A) verified internally before soft-start.

Each channel features independent feedback (FB1/FB2), programmable voltage selection via 2-bit VID inputs (V1SET1/V1SET2/V2SET1/V2SET2), and dedicated power-good outputs (PG1/PG2) with 115% rising threshold and 85% falling threshold relative to 0.6V reference. Protection includes cycle-by-cycle overcurrent detection, undervoltage lockout (75% VREF trip), and thermal shutdown at 150°C.

Key Specifications

Pinout & Package

ISL65426IRZA-T is housed in a 50-lead, 5mm × 10mm, 0.5mm pitch thin QFN package (L50.5x10) with exposed thermal pad (EPAD) connected to PGND for optimal thermal performance. The package is RoHS-compliant and Pb-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output synchronous buck regulator applications.

Compared with RTQ2132B-QA and TPS546D24, the ISL65426IRZA-T uniquely combines user-configurable 6×1A power blocks, 180° phase-sync, and VID-programmable dual outputs in a single QFN package - making it optimal for cost-sensitive, space-constrained FPGA and CPLD power where flexible current allocation and simple sequencing are essential.

Availability

ISL65426IRZA-T is available at Aetrix Electronics and suitable for FPGA power delivery, point-of-load regulation, and multi-rail embedded systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL65426IRZA-T 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 and maintains full technical and supply chain continuity for legacy Intersil power management products.

The ISL65426IRZA-T belongs to Renesas' high-integration, monolithic DC/DC regulator family designed specifically for powering low-voltage, high-current digital ICs-including FPGAs, CPLDs, and DSPs-with minimal external components and robust protection.

FAQ

What is the maximum total output current supported by the ISL65426IRZA-T?

The ISL65426IRZA-T supports up to 6A total output current, distributed across its two channels in four validated configurations: 3A:3A, 4A:2A, 5A:1A, or 2A:4A. Each of its six internal 1A power blocks is assigned to a channel based on ISET1/ISET2 logic states, and the configuration is verified before soft-start to prevent misoperation. The ISL65426IRZA-T delivers this current while maintaining efficiency up to 95% under typical conditions (e.g., 5V input, 2.5V output).

How does the ISL65426IRZA-T achieve input ripple reduction?

The ISL65426IRZA-T reduces input ripple by operating its two PWM channels 180° out-of-phase, causing their input current waveforms to partially cancel. This lowers RMS input current and minimizes voltage ripple on the shared input capacitor - enabling smaller, lower-ESR ceramic input capacitors. The effect is confirmed in the datasheet's typical performance curves and is intrinsic to the device's fixed-frequency current-mode architecture.

Can the ISL65426IRZA-T generate non-standard output voltages like 1.35V or 2.85V?

Yes, the ISL65426IRZA-T supports non-standard output voltages via external resistor dividers on FB1/FB2. When both VxSETx pins for a channel are pulled to GND, the internal reference defaults to 0.6V, allowing output adjustment from 1V to 4.0V (or up to 80% of input voltage). For example, a 1.35V output is achieved using R1 = 12.4kΩ and R2 = 10kΩ. This method is documented in Figure 36 and Equation 1 of the ISL65426IRZA-T datasheet.

What thermal management provisions does the ISL65426IRZA-T include?

The ISL65426IRZA-T integrates a thermal monitor that triggers shutdown at 150°C junction temperature and includes an exposed thermal pad (EPAD) tied to PGND for direct PCB heat sinking. Its θJA is 23°C/W and θJC is 2.5°C/W in the 50-lead QFN package. Layout best practices - such as connecting the EPAD to a large copper pour and using multiple thermal vias - are essential to maintain safe operation under full 6A load.

Does the ISL65426IRZA-T support power sequencing between its two outputs?

Yes, the ISL65426IRZA-T supports precise power sequencing via three independent enable inputs: EN1 and EN2 control each channel individually, while EN provides system-level sequencing for multi-input bias supply designs. By controlling the timing of these signals, designers can implement staggered startup (e.g., core before I/O) or simultaneous activation. The device also features independent power-good outputs (PG1/PG2) to feed back status to system controllers.