Renesas ISL6506BIBZ

Overview

ISL6506BIBZ from Intersil is a multiple linear power controller with ACPI control interface, designed for motherboard-level 5VDUAL and 3.3VDUAL rail management in microprocessor systems. It integrates an internal 2A 3.3V LDO, dual switch controllers for 5V/3.3V ATX rail switching, and digital S3/S5 state selection - enabling precise sleep-state power sequencing in S0/S3/S4-S5 ACPI states.

For engineers reviewing the ISL6506BIBZ datasheet, ISL6506BIBZ pinout, ISL6506BIBZ application, or ISL6506BIBZ equivalent, key selection criteria include its 8-lead EPAD SOIC package, ±2% 3.3VDUAL regulation over temperature, 2A internal LDO current limit, S3/S5 digital control interface, and thermal shutdown at 140°C - all critical for legacy ACPI-compliant PC power design validation.

Technical Context

The ISL6506BIBZ implements a hybrid regulation architecture: during S0/S1/S2, it routes ATX 3.3V and 5V directly via external N-MOSFETs controlled by DLA and 5VDLSB pins; during S3, it delivers regulated 3.3VDUAL from 5VSB via internal LDO while switching 5VDUAL from 5VSB using a P-MOSFET. Its POR circuit monitors both 5VSB (4.5V rising threshold) and 12V (9.8V typical rising threshold) to ensure safe S0 entry.

Functional timing includes 60µs S0→S3 transition delay, 8.2ms typical soft-start interval, and undervoltage protection on 3.3VDUAL active only in sleep states with 2.5V trip point. The IC enforces illegal state blocking (e.g., S4/S5 → S3) and uses internal 10µA pull-downs on S3/S5 pins for robust digital interface behavior.

Key Specifications

Pinout & Package

ISL6506BIBZ is housed in an 8-lead Exposed Pad Small Outline Integrated Circuit (EPSOIC) package per drawing M8.15C, with thermal pad (EPAD) tied to GND for enhanced heat dissipation. Package dimensions: 4.80–4.98mm × 3.81–3.99mm × 1.43–1.68mm height, 0.65mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL6506BI, the ISL6506BIBZ offers superior thermal performance via EPAD; compared with RT8059GQW, it delivers native ACPI compliance with zero external logic - making it the only drop-in solution for legacy ATX motherboard upgrades requiring S3/S4/S5 support.

Availability

ISL6506BIBZ is available at Aetrix Electronics and suitable for desktop motherboard power management, legacy ACPI PC platform regulation, and embedded x86 system power sequencing requiring stable component supply across extended temperature ranges and long-lifecycle programs.

Supply support for ISL6506BIBZ 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 Corporation (now part of Renesas Electronics) designs high-performance analog and power management ICs for computing, industrial, and communications markets - with emphasis on energy efficiency and system integration.

The ISL6506BIBZ belongs to Intersil's ACPI Power Controller product line, developed specifically to simplify dual-rail voltage management in ATX-compliant PC platforms while meeting strict ACPI 2.0 timing and regulation requirements.

FAQ

What is the primary function of the ISL6506BIBZ in an ATX motherboard design?

The ISL6506BIBZ serves as a dual-rail ACPI power controller that manages both the 5VDUAL and 3.3VDUAL voltage planes. In active states (S0/S1/S2), it switches ATX 5V and 3.3V directly to outputs using external MOSFETs; in S3 sleep, it regulates 3.3VDUAL from 5VSB via its internal 2A LDO and connects 5VDUAL to 5VSB using a P-MOSFET. This eliminates discrete sequencing logic and reduces BOM count while ensuring strict ACPI compliance - a core function confirmed in FN7814 Rev 2.00 Section 1 and Block Diagram.

Does the ISL6506BIBZ support S4/S5 sleep states, and how does it behave in those modes?

Yes, the ISL6506BIBZ fully supports S4/S5 sleep states. In S4/S5 (S5=0, S3=0), the 5VDUAL output is shut down completely, while the 3.3VDUAL rail remains active and regulated by the internal LDO from 5VSB. The device enters this state automatically when both S3 and S5 pins are driven low, and it enforces a hard block against illegal transitions such as returning directly to S3 from S4/S5. This behavior is defined in Table 1 and Functional Description on Page 4 of FN7814 Rev 2.00.

What is the role of the DLA pin on the ISL6506BIBZ, and what external component is required?

The DLA pin is an open-drain output used to drive the gates of external N-MOSFETs (Q1 and Q3) that connect ATX 3.3V and 5V to the 3.3VDUAL and 5VDUAL outputs in active states. A 1kΩ pull-up resistor must be connected from DLA to the ATX 12V rail - this resistor sets the POR threshold for the 12V monitor and enables proper MOSFET enhancement. Using any other value alters the POR level, as explicitly stated in the Functional Pin Description on Page 4 of FN7814 Rev 2.00.

How does the ISL6506BIBZ handle overcurrent conditions on its internal 3.3VDUAL LDO?

When overcurrent is detected on the internal 3.3VDUAL LDO, the ISL6506BIBZ reduces the gate voltage to the internal NMOS pass element, causing the output voltage to drop. If the voltage falls to the undervoltage trip point (2.5V), the undervoltage protection triggers and shuts down the LDO. After one soft-start interval, it retries up to three times; a fourth undervoltage event disables the LDO permanently until a POR reset occurs. This sequence is documented in the "Internal Linear Regulator Overcurrent Protection" section on Page 5 of FN7814 Rev 2.00.

Is the ISL6506BIBZ RoHS compliant, and what packaging details confirm this?

Yes, the ISL6506BIBZ is RoHS compliant and Pb-free. The Ordering Information table on Page 1 of FN7814 Rev 2.00 explicitly lists "Pb-free (RoHS Compliant)" under PACKAGE, and Note 2 confirms it employs 100% matte tin plate (e3 termination finish) compatible with both SnPb and Pb-free soldering. The package is designated "8 Ld EPSOIC" with drawing number M8.15C - consistent with Intersil's Pb-free plastic packaging standards described in TB347 and TB363.