Renesas ISL6236IRZA-TR5281

Overview

ISL6236IRZA-TR5281 from Intersil is a quad-output, dual-step-down main power supply controller for notebook computers, integrating two constant-on-time PWM controllers (SMPS1: 0.7–5.5V adjustable or fixed 1.5V/5.0V; SMPS2: 0V–2.5V adjustable or fixed 1.05V/3.3V), a 3.3V/5V linear regulator (100mA continuous, 200mA switchover), and dual power-good outputs. It supports ultrasonic skip mode (>25kHz), 100ns load-step response, and operates across 5.5V–25V input with up to 97% efficiency.

For engineers reviewing the ISL6236IRZA-TR5281 datasheet, ISL6236IRZA-TR5281 pinout, ISL6236IRZA-TR5281 application, or ISL6236IRZA-TR5281 equivalent, key selection considerations include its dual independent enable inputs (EN1/EN2), programmable current limit with foldback, selectable PWM/skip/ultrasonic modes, and integrated 3.3V/5V reference outputs (REF, VREF3) for DDR memory and CPU core rail sequencing.

Technical Context

The ISL6236IRZA-TR5281 implements constant-on-time control without external sense resistors, enabling 100ns transient response while maintaining stable switching frequencies (200/300/400/500 kHz selectable via TON pin). Its dual PWM channels operate independently with separate feedback (FB1, REFIN2), enable (EN1, EN2), and power-good (POK1, POK2) signals, supporting precise voltage sequencing in multi-rail systems.

It integrates an internal LDO with bootstrapping capability (BYP pin), dual MOSFET gate drivers (UGATE1/LGATE1 and UGATE2/LGATE2), secondary feedback monitoring (SECFB) for external charge pumps, and digital soft-start (1.7ms) with pre-biased output support - all within a single 32-pin 5×5 QFN package rated for –40°C to +100°C operation.

Key Specifications

Pinout & Package

ISL6236IRZA-TR5281 is housed in a Pb-free, RoHS-compliant 32-lead 5mm × 5mm QFN package (L32.5x5B) with exposed thermal pad. The package supports high-power density designs and efficient heat dissipation (θ_JA = 32°C/W, θ_JC = 3.0°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output notebook power controller applications.

Compared with RT8205AZSP and TPS51220ARUKT, the ISL6236IRZA-TR5281 offers broader output adjustability (0.7V–5.5V on SMPS1), lower quiescent power (5mW), and ultrasonic skip mode - making it optimal for legacy and cost-sensitive notebook platforms where flexibility and audio-noise suppression are prioritized over integration or VR compliance.

Availability

ISL6236IRZA-TR5281 is available at Aetrix Electronics and suitable for notebook computers, DDR memory power supplies, and mobile graphics core applications requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for ISL6236IRZA-TR5281 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

Intersil (now part of Renesas Electronics) is a semiconductor company specializing in high-performance analog and power management ICs for computing, communications, and industrial markets.

The ISL6236 product line was designed specifically for notebook and sub-notebook main power systems, delivering quad-output voltage regulation with integrated sequencing, high efficiency, and ultra-low noise operation.

FAQ

What is the operating temperature range for the ISL6236IRZA-TR5281?

The ISL6236IRZA-TR5281 is rated for operation from –40°C to +100°C ambient temperature, with a maximum junction temperature of +150°C. This extended range supports deployment in thermally demanding notebook chassis environments, including near CPU/GPU hotspots and passive-cooled ultrabooks. Thermal performance is enhanced by the exposed pad in its 5×5 QFN package.

How does the ISL6236IRZA-TR5281 achieve 100ns load-step response?

The ISL6236IRZA-TR5281 achieves 100ns load-step response through its constant-on-time (COT) control architecture, which eliminates loop compensation and directly modulates switch timing based on output voltage deviation. This design bypasses traditional error amplifier delays and enables immediate pulse-width adjustment without external sense resistors - a key advantage for CPU/GPU transient loads.

Can the ISL6236IRZA-TR5281 support DDR3 VTT termination?

Yes, the ISL6236IRZA-TR5281 supports DDR3 VTT termination via its SMPS2 channel, which can be configured for 0.75V output (half of 1.5V VDDQ) using a resistive divider on REFIN2. With ±1.5% output accuracy, 100ns transient response, and ultrasonic skip mode to avoid interference, it meets JEDEC DDR3 VTT regulation and noise requirements.

What is the purpose of the SECFB pin on the ISL6236IRZA-TR5281?

The SECFB pin on the ISL6236IRZA-TR5281 monitors an optional external 14V charge pump. When the divided SECFB voltage drops below 2.0V threshold, LGATE1 pulses for 300ns to refresh the pump without over-discharging. This enables reliable high-side gate drive for SMPS1 in high-input-voltage configurations where bootstrap capacitor recharge is otherwise insufficient.

Does the ISL6236IRZA-TR5281 include built-in power-good signaling?

Yes, the ISL6236IRZA-TR5281 includes two independent open-drain power-good outputs: POK1 for SMPS1 and POK2 for SMPS2. Each asserts low during soft-start, output undervoltage (>9% drop), or shutdown, and goes high-impedance when regulation is stable - enabling direct connection to processor reset inputs or FPGA configuration logic without external pull-ups.