Renesas ISL6530CR

Overview

ISL6530CR from Intersil is a dual 5V synchronous buck PWM controller optimized for DDRAM memory VDDQ (2.5V ±2%), VREF (½ × VDDQ ±1%), and VTT (VREF ±30mV) regulation. It integrates two phase-displaced 300kHz oscillators, 15MHz GBW error amplifiers, and rDS(ON)-based overcurrent protection for the VDDQ regulator. Used in AMD Athlon/K8, Pentium III/IV, PowerPC, and UltraSparc main memory systems.

For engineers reviewing the ISL6530CR datasheet, ISL6530CR pinout, ISL6530CR application, or ISL6530CR equivalent, key selection criteria include its QFN-32 package, V2_SD sleep-mode support, dual-output tracking architecture, and MOSFET gate drive capability (±1A UGATE, ±2A LGATE).

Technical Context

The ISL6530CR implements voltage-mode control with two independent 300kHz triangle-wave oscillators locked in 90° phase offset to minimize inter-regulator noise coupling. Each regulator uses a dedicated error amplifier (15MHz GBW, 6V/μs slew rate) and external compensation network across FB/COMP pins.

VDDQ regulation relies on a precision 0.8V internal reference and resistor-divider feedback; VTT regulation tracks VREF via SENSE2, with a low-power window regulator active during V2_SD sleep mode. Overcurrent protection for VDDQ uses the upper MOSFET's rDS(ON) without a sense resistor, triggering hiccup-mode soft-start recovery.

Key Specifications

Pinout & Package

ISL6530CR is housed in a 32-lead, 5mm × 5mm QFN package with exposed thermal pad (PKG DWG # L32.5x5), rated θJA = 33°C/W and θJC = 4°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL6530CR, ISL6522CR provides only VDDQ regulation and requires external circuitry for VTT, while RT8120AGQW lacks DDRAM-specific features like VREF derivation, VTT tracking, and V2_SD sleep-mode support-making ISL6530CR uniquely suited for complete DDRAM power delivery in one IC.

Availability

ISL6530CR is available at Aetrix Electronics and suitable for desktop motherboard design, server memory subsystems, and graphics card video memory applications requiring stable component supply, RoHS-compliant packaging, and legacy DDRAM power architecture support.

Supply support for ISL6530CR 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, precision references, and interface solutions.

The ISL6530CR belongs to Intersil's DDRAM power management product line, engineered specifically to consolidate VDDQ, VREF, and VTT regulation into a single controller for first-generation DDR SDRAM systems.

FAQ

What is the primary function of the ISL6530CR in DDRAM memory systems?

The ISL6530CR serves as a dual-output synchronous buck PWM controller that generates and regulates three critical DDRAM supply rails: VDDQ (2.5V), VREF (½ × VDDQ), and VTT (VREF ±30mV). It integrates all control, feedback, protection, and gate drive functions required for complete DDRAM power delivery in a single 32-pin QFN package.

Does the ISL6530CR support sleep-mode operation for VTT, and how does it work?

Yes, the ISL6530CR supports VTT sleep mode via the V2_SD pin. When V2_SD is driven high, the main VTT regulator shuts down and a low-power window regulator activates, holding VTT at approximately ½ × VDDQ with ±7% accuracy and ±10mA load capability. This enables rapid wake-up without requiring VTT soft-start, and PGOOD is held low during this state.

How does overcurrent protection work in the ISL6530CR, and which output does it monitor?

The ISL6530CR implements overcurrent protection exclusively on the VDDQ regulator using the rDS(ON) of the upper MOSFET. A resistor (ROCSET) sets the trip threshold according to I_PEAK = (I_OCSET × R_OCSET) / r_DS(ON). When exceeded, the controller enters hiccup-mode recovery-shutting down and executing three soft-start cycles before attempting regulation again.

Can the ISL6530CR generate VTT independently of VDDQ, or is tracking mandatory?

VTT regulation in the ISL6530CR is inherently tied to VDDQ via the internal 50% resistor divider that generates VREF from SENSE1. However, VREF_IN allows external override: applying an external reference to VREF_IN bypasses the internal divider, enabling independent VTT setpoint-but SENSE1 must remain unconnected, and VTT loses automatic tracking and soft-start coordination with VDDQ.

What package type and thermal characteristics apply to the ISL6530CR?

The ISL6530CR uses a 32-lead, 5mm × 5mm QFN package (drawing L32.5x5) with an exposed thermal pad. Its thermal resistance is θ_JA = 33°C/W and θ_JC = 4°C/W, supporting junction temperatures up to 125°C under continuous operation and 150°C maximum. The exposed pad must be soldered to a solid copper thermal plane for optimal performance.