Renesas ISL8025AIRTAJZ

Overview

ISL8025AIRTAJZ from Renesas Electronics is a monolithic synchronous buck regulator delivering 5A continuous output current from a 2.7V–5.5V input, featuring 2MHz default switching frequency, 0.6V reference voltage, and integrated 36mΩ P-channel / 13mΩ N-channel MOSFETs. It supports forced continuous or discontinuous conduction mode and is used in point-of-load power for FPGAs and microcontrollers.

For engineers reviewing the ISL8025AIRTAJZ datasheet, ISL8025AIRTAJZ pinout, ISL8025AIRTAJZ application, or ISL8025AIRTAJZ equivalent, key selection criteria include its 2MHz fixed-frequency operation (vs. 1MHz for ISL8025), 0.8% VREF accuracy over temperature/load/line, 100% duty-cycle capability for <180mV dropout at 5A, and thermal shutdown at 150°C with 25°C hysteresis.

Technical Context

The ISL8025AIRTAJZ uses current-mode control architecture to ensure fast transient response and stable loop behavior across 500kHz–4MHz programmable switching frequencies. Its internal compensation path connects COMP to VDD, while external compensation requires dedicated network design across COMP and SGND.

It integrates hiccup-mode overcurrent protection, overvoltage and under-voltage monitoring via FB, negative current limiting (−3A typical), and soft-stop discharge during shutdown. The PG output provides 1ms delay upon regulation and monitors output within ±30mV hysteresis.

Key Specifications

Pinout & Package

ISL8025AIRTAJZ is housed in a RoHS-compliant 16-lead 3mm × 3mm TQFN package with exposed thermal pad, 1mm maximum height, and optimized layout for high-current paths and thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL8025IRTAJZ, the ISL8025AIRTAJZ offers higher default frequency for smaller passives, while TPS54560BQPWPRQ1 trades integration for wider input range-neither is pin-compatible, and both require PCB redesign for substitution.

Availability

ISL8025AIRTAJZ is available at Aetrix Electronics and suitable for DC/DC POL modules, μC/FPGA power supplies, and Li-ion battery-powered devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL8025AIRTAJZ 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 specializing in microcontrollers, analog power management, and timing solutions for industrial, automotive, and computing markets.

The ISL8025A product line delivers highly integrated, high-efficiency synchronous buck regulators targeting space-constrained, high-performance point-of-load applications in portable and infrastructure equipment.

FAQ

What is the default switching frequency of the ISL8025AIRTAJZ?

The ISL8025AIRTAJZ has a factory-set default switching frequency of 2MHz when the FS pin is connected to VIN. This differs from the ISL8025 (1MHz default) and enables smaller external inductors and capacitors. Frequency can be adjusted between 500kHz and 4MHz using an external resistor from FS to SGND, as specified in the FN8357 datasheet.

Does the ISL8025AIRTAJZ support 100% duty-cycle operation?

Yes, the ISL8025AIRTAJZ supports 100% duty-cycle operation, enabling output voltages approaching the input rail with minimal dropout-less than 180mV at 5A load. This feature is critical for maintaining regulation during battery brownout conditions in Li-ion-powered devices and is implemented via internal control logic that disables the low-side FET while keeping the high-side FET fully enhanced.

How does the power-good (PG) function work on the ISL8025AIRTAJZ?

The ISL8025AIRTAJZ PG pin is an open-drain output that asserts high (via external pull-up) only after the output reaches regulation and remains stable for 1ms. It monitors the FB node and triggers a falling edge if VOUT drops below 0.48V or rises above 0.80V. PG leakage is ≤0.1µA, and output low voltage is ≤0.3V at 1mA sink, ensuring clean interface with FPGA or microcontroller reset controllers.

Can the ISL8025AIRTAJZ be synchronized to an external clock?

Yes, the ISL8025AIRTAJZ SYNC pin accepts an external clock signal up to 4MHz with positive-edge triggering, allowing synchronization to system clocks for EMI reduction. When not synchronized, SYNC can be pulled high (PWM mode) or low (PFM mode). An internal 1MΩ pull-down prevents floating states, and SYNC input leakage is ≤5µA at 3.6V, minimizing interference with timing sources.

What thermal performance can be expected from the ISL8025AIRTAJZ in a standard PCB layout?

In a standard 4-layer PCB with the exposed thermal pad soldered to a 1-in² SGND plane using ≥6 thermal vias, the ISL8025AIRTAJZ achieves θ_JA = 47°C/W and θ_JC = 6.5°C/W. At 5A load and 5V input, junction temperature rise is typically <45°C above ambient, well below the 150°C thermal shutdown threshold. Layout adherence to Renesas' recommendations in FN8357 page 20 is essential to maintain this performance.