Renesas ISL6532AIRZ

Overview

ISL6532AIRZ from Intersil is an ACPI-compliant dual-channel DDR/DDR2 memory power controller integrating a 250kHz synchronous buck PWM controller, a 3A sink-source VTT linear regulator with precise VDDQ/2 reference, and a standby LDO for VDDQ in S3 state - all in a single 28-pin QFN package. It delivers ±2% output regulation across line, load, and temperature for VDDQ, VTT, and AGP core (1.5V) rails in ATX-based desktop and graphics memory systems.

For engineers reviewing the ISL6532AIRZ datasheet, ISL6532AIRZ pinout, ISL6532AIRZ application, or ISL6532AIRZ equivalent, this device supports cold-start sequencing, glitch-free S0↔S3 transitions, backfeed blocking via NCH control, integrated overcurrent and thermal protection, and RoHS-compliant Pb-free packaging for industrial-temperature (-40°C to +85°C) deployment.

Technical Context

The ISL6532AIRZ implements voltage-mode PWM control with 250kHz fixed-frequency operation and fast transient response for the main VDDQ buck regulator. Its internal 0.8V precision reference sets VDDQ via external resistor divider on FB, while VTT is generated as a buffered, accurate VDDQ/2 using integrated sink-source circuitry - eliminating need for negative supply.

ACPI state management is hardware-driven: S3# and S5# inputs directly control regulator enable/disable sequencing, soft-start reset timing, and PGOOD assertion. The NCH open-drain output synchronizes backfeed-blocking MOSFET switching during sleep transitions, and VTTSNS provides dedicated feedback for VTT regulation accuracy.

Key Specifications

Pinout & Package

ISL6532AIRZ uses a JEDEC MO-220-compliant 28-lead 6×6 mm QFN package with exposed thermal pad (PKG DWG # L28.6x6). Pin functions are validated per FN9099 Rev 6.00 datasheet, Page 2 (top view).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar DDR memory power controller applications.

Compared with ISL6532ACRZ, the ISL6532AIRZ adds industrial temperature qualification and wider thermal margin; compared with RT8105DGQW, it integrates full VTT regulation and S3 standby capability - reducing external components and simplifying layout for DDR2 systems.

Availability

ISL6532AIRZ is available at Aetrix Electronics and suitable for desktop motherboards, graphics cards, ASIC memory interfaces, and embedded industrial DDR2 systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ISL6532AIRZ 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 precision analog, power management, and interface ICs for computing, industrial, and communications markets.

The ISL6532AIRZ belongs to Intersil's ACPI-compliant memory power controller product line, designed specifically to consolidate DDR/DDR2 memory rail generation, termination, and state-aware power management into a single-package solution for ATX-based platforms.

FAQ

What is the primary function of the ISL6532AIRZ in a DDR memory system?

The ISL6532AIRZ serves as a complete ACPI-compliant power controller for dual-channel DDR/DDR2 memory systems. It integrates three regulated outputs: a synchronous buck PWM controller for VDDQ, a 3A sink-source linear regulator for VTT (at VDDQ/2), and a standby LDO for VDDQ during S3 sleep state. The ISL6532AIRZ manages all state transitions, overcurrent protection, thermal shutdown, and PGOOD signaling without external firmware or logic.

Does the ISL6532AIRZ support both DDR2 and DDR3 memory standards?

The ISL6532AIRZ is explicitly designed for DDR and DDR2 memory systems, as confirmed by its datasheet title ("ACPI Regulator/Controller for Dual Channel DDR Memory Systems") and supported output ranges (adjustable down to 0.8V, covering DDR 2.5V and DDR2 1.8V). It does not support DDR3-specific requirements such as ZQ calibration or 1.5V VDDQ operation - those are addressed by later-generation controllers like the ISL6537 or RT8105.

How does the ISL6532AIRZ implement overcurrent protection without a sense resistor?

The ISL6532AIRZ uses the upper MOSFET's intrinsic rDS(ON) as the current-sensing element. An internal 20µA current source (IOCSET) flows through an external resistor (ROCSET) tied to the upper FET drain, generating a reference voltage. When the voltage drop across the upper FET exceeds this reference, the overcurrent comparator triggers soft-start reset. This method eliminates the need for a discrete sense resistor, preserving efficiency and board space in the ISL6532AIRZ design.

What is the role of the NCH pin on the ISL6532AIRZ, and how must it be connected?

The NCH pin on the ISL6532AIRZ is an open-drain output that controls an external backfeed-blocking MOSFET during sleep state transitions. It must be pulled up to the 12V rail via a ≥2kΩ resistor. When active, NCH pulls low to disable the blocking FET and prevent reverse current flow from VDDQ to the input rail during S3/S4/S5 states. Even if unused, NCH requires this pull-up to ensure proper PWM enable timing - failure to connect it may cause startup failure or erratic regulation behavior in the ISL6532AIRZ.

Can the ISL6532AIRZ operate with a 3.3V standby input instead of 5VSBY?

Yes - the ISL6532AIRZ supports both 5VSBY and 3.3VSBY inputs for its standby LDO. However, the datasheet specifies higher output current capability when powered from 5VSBY (650mA vs. 550mA at 3.3VSBY), and recommends using the 5V rail for S3-state VDDQ supply due to superior load handling. The 5VSBY pin (Pin 2) serves as the main bias supply, while P5VSBY (Pin 11) selects the standby LDO input source - allowing flexible integration in mixed-rail ATX designs using the ISL6532AIRZ.