Renesas ISL6505CRZ

Overview

ISL6505CRZ from Intersil is a multiple linear power controller with ACPI control interface, designed for motherboard-level power management in microprocessor systems. It integrates four regulated outputs - 3.3VDUAL/3.3VSB (3.3V), 5VDUAL (5V), 1.2VVID, and programmable VOUT1 (1.2–1.5V) - with digital S3/S5 sleep-state control, undervoltage monitoring, and thermal shutdown. It operates across 0°C to 70°C and supports ATX-compliant PC power sequencing.

For engineers reviewing the ISL6505CRZ datasheet, ISL6505CRZ pinout, ISL6505CRZ application, or ISL6505CRZ equivalent, this device serves as a critical ACPI-compliant power controller for legacy desktop/server motherboards requiring coordinated 3.3V/5V/1.2V rail control, sleep-state transitions (S0–S5), and fault reporting via FAULT pin.

Technical Context

The ISL6505CRZ implements three linear regulators (3.3VDUAL/3.3VSB, 1.2VVID, VOUT1) and one dual-mode switching controller (5VDUAL), all synchronized to ACPI state logic via S3/S5 inputs. Its internal soft-start circuit uses a 10µA current source and external CSS capacitor to ramp output voltages in two controlled phases.

It features independent undervoltage detection on all four outputs plus monitored ATX rails (3V3, 5V), centralized FAULT reporting, and temperature monitoring with 125°C fault threshold and 155°C shutdown. The LAN pin selects VOUT1 persistence (always-on vs. active-only), while EN5 configures 5VDUAL behavior in S5 state.

Key Specifications

Pinout & Package

ISL6505CRZ is housed in a 20-lead, 5×5 mm QFN package (JEDEC MO-220 compliant) with exposed thermal pad tied to GND. Pin numbering follows standard top-view orientation; Pin 1 (FB1) is marked by dot or notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multiple-rail ACPI power controller applications.

Compared with ISL6505CBZ, the ISL6505CRZ offers superior thermal performance and smaller footprint for high-density motherboards, while RT8205AZQW lacks ACPI state control and requires redesign of sleep-state sequencing logic.

Availability

ISL6505CRZ is available at Aetrix Electronics and suitable for desktop motherboard design, server board power management, and legacy PC platform development requiring stable component supply and long-term lifecycle support.

Supply support for ISL6505CRZ 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 and power management ICs for computing, industrial, and communications markets.

The ISL6505 product line was designed specifically for ACPI-compliant PC motherboard power sequencing, integrating linear regulation, switching control, and state-aware monitoring into a single package for x86 platform designers.

FAQ

What is the primary function of the ISL6505CRZ in a PC motherboard?

The ISL6505CRZ serves as a multiple linear power controller with ACPI interface, managing four critical voltage rails - 3.3VDUAL/3.3VSB, 5VDUAL, 1.2VVID, and programmable VOUT1 - while enforcing S0–S5 sleep-state transitions. It replaces discrete regulators and logic in ATX-compliant systems, ensuring coordinated power-up/down sequences and fault reporting via the FAULT pin. Its design directly supports legacy x86 motherboard architectures requiring strict ACPI compliance.

How does the ISL6505CRZ handle undervoltage conditions across its outputs?

The ISL6505CRZ monitors all four regulated outputs (3.3VDUAL, 5VDUAL, 1.2VVID, VOUT1) plus ATX 3V3 and 5V rails for undervoltage events. Each has defined rising/falling thresholds (e.g., 3.3VDUAL UV rising threshold = 2.62V) and hysteresis (e.g., 150 mV). Any detected UV condition pulls the FAULT pin high to 5VSB, signaling system-level fault without latching - except for 1.2VVID, which shuts down internally upon fault. This centralized reporting simplifies host system diagnostics.

Can the ISL6505CRZ be used in new designs, and what is its lifecycle status?

The ISL6505CRZ is an obsolete product with no recommended replacement, as noted in the official datasheet (FN9109 Rev 3.00). However, Aetrix Electronics maintains verified inventory and supports ongoing production for legacy motherboard repair, refurbishment, and long-life industrial deployments. Customers should consult Renesas' technical support for migration paths, but the ISL6505CRZ remains fully functional and electrically identical to original specifications for existing designs.

What is the role of the SS (Soft-Start) pin on the ISL6505CRZ?

The SS pin on the ISL6505CRZ controls both soft-start timing and emergency shutdown. An external capacitor (typically 0.1 µF) forms a ramp with the internal 10 µA current source, enabling two-phase voltage ramp-up: first 3.3VDUAL/VOUT1, then 1.2VVID/5VDUAL. Pulling SS below 0.8V forces immediate shutdown of all outputs and resets the FAULT pin - a hardware-level safety feature usable by system watchdogs or thermal cutoff circuits. This dual function ensures robust start-up and fail-safe operation.

How does the LAN pin affect VOUT1 behavior in different ACPI states?

The LAN pin on the ISL6505CRZ selects VOUT1 operational mode: logic high (or open) enables 10/100 LAN mode, keeping VOUT1 active across all ACPI states (S0–S5); logic low enables Gigabit Ethernet mode, restricting VOUT1 to active states only (S0–S2). This mapping is confirmed in Table 2 of the datasheet and is independent of VOUT1's resistor-programmed voltage (1.2–1.5V). The selection is static - intended to be hardwired, not dynamically toggled - aligning with real-world Ethernet PHY power requirements.