Renesas ISL6530CR-T

Overview

ISL6530CR-T from Intersil is a dual 5V synchronous buck PWM controller IC designed for DDRAM memory power delivery, generating VDDQ (2.5V ±2%), VREF (½×VDDQ ±1%), and VTT (VREF ±30mV) with integrated overcurrent protection using MOSFET r_DS(ON) sensing. It drives low-cost N-channel MOSFETs in two phase-shifted (90°) 300kHz buck regulators for main memory in Pentium IV, Athlon K8, and PowerPC-based systems.

For engineers reviewing the ISL6530CR-T datasheet, ISL6530CR-T pinout, ISL6530CR-T application, or ISL6530CR-T equivalent, key selection considerations include its dual-output DDR termination architecture, V2_SD sleep-mode window regulator for rapid wake-up, voltage-mode control with 15MHz GBW error amplifiers, and SOIC/QFN package options supporting industrial-temperature DDR memory designs.

Technical Context

The ISL6530CR-T integrates two independent synchronous buck controllers: VDDQ/VREF regulator with 0.8V internal reference and precision resistor-divider-derived VREF output, and VTT regulator referenced directly to VREF. Both use voltage-mode control with 300kHz fixed-frequency triangle-wave oscillators phase-displaced by 90° to reduce input ripple and EMI coupling.

It implements adaptive shoot-through protection-using PHASE1/LGATE1 monitoring for VDDQ and UGATE2/LGATE2 threshold detection for VTT-and supports current sinking on VTT via bidirectional gate drive logic. Overcurrent protection operates in hiccup mode, triggered by r_DS(ON)-based sensing without external sense resistors.

Key Specifications

Pinout & Package

ISL6530CR-T uses a 32-lead, 5mm × 5mm QFN package (PKG DWG # L32.5x5) with exposed thermal pad for enhanced thermal performance (θ_JA = 33°C/W). Pin functions are validated per FN9052 Rev 2.00 datasheet, Page 6.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output DDR memory regulator applications.

Compared with ISL6537IRZ-T and TPS51100PWR, the ISL6530CR-T provides the most direct fit for legacy DDR2 systems needing V2_SD-enabled rapid wake-up, r_DS(ON) current sensing, and minimal external component count - making it ideal for industrial DDR2 memory upgrades and cost-constrained designs.

Availability

ISL6530CR-T is available at Aetrix Electronics and suitable for desktop CPU memory power, graphics card VRAM supply, server memory module regulation, and embedded power management requiring stable component supply and long-lifecycle support.

Supply support for ISL6530CR-T 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) is a U.S.-based analog and power management IC designer known for high-performance DC-DC controllers and precision voltage references.

The ISL6530 product line was developed specifically for DDR SDRAM memory power delivery, addressing the need for tightly tracked VDDQ/VTT/VREF rails with integrated protection and low-latency sleep/wake functionality in early-2000s computing platforms.

FAQ

What is the primary function of the ISL6530CR-T in DDR memory systems?

The ISL6530CR-T serves as a dual synchronous buck PWM controller that generates and regulates three critical DDR memory voltages: VDDQ (2.5V), VREF (½×VDDQ), and VTT (VREF-tracked). It integrates all control, feedback, protection, and gate drive functions into a single 32-lead QFN package, enabling compact, efficient, and JEDEC-compliant DDR2 memory power solutions. The ISL6530CR-T is specifically optimized for platforms including Pentium IV, Athlon K8, and PowerPC-based systems.

Does the ISL6530CR-T support S3 sleep mode, and how does it maintain VTT during sleep?

Yes, the ISL6530CR-T supports S3 sleep mode via the V2_SD input pin. When V2_SD is driven high, the main VTT PWM regulator is disabled and both upper and lower MOSFETs are turned off. A dedicated low-power window regulator then maintains VTT at approximately ½×VDDQ (±7% error under ±10mA load) through the SENSE2 pin. This architecture enables rapid wake-up without requiring VTT soft-start, preserving system responsiveness. The ISL6530CR-T's V2_SD feature is confirmed in FN9052 Rev 2.00, Pages 4 and 7.

How does overcurrent protection work on the ISL6530CR-T, and what components are required?

The ISL6530CR-T implements overcurrent protection for the VDDQ regulator using the r_DS(ON) of the upper MOSFET - eliminating the need for an external current-sense resistor. A resistor (ROCSET) connected from the OCSET/SD pin to the upper MOSFET drain sets the trip threshold according to I_PEAK = (I_OCSET × R_OCSET) / r_DS(ON), where I_OCSET is a 40μA internal current source. Upon overcurrent detection, the ISL6530CR-T enters hiccup-mode soft-start recovery. No additional sensing components are required beyond ROCSET and the MOSFET itself.

What is the difference between the ISL6530CR-T and the ISL6530CB-T package variants?

The ISL6530CR-T uses a 32-lead, 5mm × 5mm QFN package (PKG DWG # L32.5x5) with exposed thermal pad, offering θ_JA = 33°C/W and θ_JC = 4°C/W for improved thermal performance in space-constrained or thermally demanding applications. In contrast, the ISL6530CB-T uses a 24-lead SOIC package (PKG DWG # M24.3) with θ_JA = 65°C/W and no thermal pad. Both share identical electrical specifications and pin functions per channel, but the ISL6530CR-T enables higher power density and better thermal management in modern DDR2 memory modules.

Can the ISL6530CR-T be used for DDR3 memory applications?

No, the ISL6530CR-T is not suitable for DDR3 memory applications. It was designed for DDR2 systems with VDDQ = 2.5V and VTT tolerance of ±30mV. DDR3 requires VDDQ = 1.8V and tighter VTT regulation (±15mV), along with faster transient response and updated timing parameters. The ISL6537IRZ-T is Intersil's designated successor for DDR3, offering triple-output support, enhanced accuracy, and DDR3-specific features. Using the ISL6530CR-T in DDR3 designs would violate JEDEC voltage and timing specifications.