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Renesas ISL95821CRTZ-T
- Part No.:
- ISL95821CRTZ-T
- Manufacturer:
- Renesas
- Category:
- Special Purpose Regulators
- Package:
- 40-VFQFN Exposed Pad
- Datasheet:
-
ISL95821CRTZ-T.pdf
- Description:
- IC REG CTRLR VR12.5 1OUT 40TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,561
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Product details
Overview
ISL95821CRTZ-T from Renesas (formerly Intersil) is a three-phase PWM controller IC designed for Intel VR12.5™ CPU core power delivery, featuring R3™ modulator architecture, 0.5% system voltage accuracy over temperature, integrated gate drivers, and support for DCR/resistor current sensing. It enables phase shedding, diode emulation mode, and programmable VBOOT, IMAX, and slew rate in desktop VR applications.
For engineers reviewing the ISL95821CRTZ-T datasheet, ISL95821CRTZ-T pinout, ISL95821CRTZ-T application, or ISL95821CRTZ-T equivalent, key selection considerations include VR12.5 serial bus compliance, R3™ transient response performance, phase configuration flexibility (1/2/3-phase), remote voltage sensing capability, and DCR temperature compensation via single NTC thermistor.
Technical Context
The ISL95821CRTZ-T implements Intersil's Robust Ripple Regulator R3™ technology, delivering variable switching frequency during load transients and diode emulation in single-phase operation to improve light-load efficiency. It supports Intel VR12.5™ serial control bus communication with the CPU for dynamic VID updates and power-state coordination.
This controller integrates three high-side/low-side gate drivers, accepts differential remote sense inputs, and provides resistor-programmable parameters including IMAX, loadline slope, switching frequency, and VBOOT startup voltage - all while maintaining 0.5% output voltage accuracy across temperature and line/load conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Control Architecture | R3™ modulator with variable-frequency response to load transients |
| Phase Support | Configurable 1-, 2-, or 3-phase operation with integrated drivers |
| Voltage Accuracy | ±0.5% over temperature, critical for VR12.5 CPU core regulation |
| Current Sensing | Supports lossless DCR sensing with single NTC thermistor or precision resistor sensing |
| Serial Interface | Intel VR12.5™-compliant serial bus for VID updates and power-state signaling |
| Remote Sensing | Differential remote voltage sense for accurate load-point regulation |
| Startup Control | Programmable VBOOT voltage to manage inrush and bootstrap capacitor charging |
Pinout & Package
ISL95821CRTZ-T is housed in a 48-pin QFN package (7mm × 7mm, 0.5mm pitch) with exposed thermal pad. Pin functions are defined per the official ISL95821 datasheet (FN8438), including dedicated phase driver outputs (PHASE1–PHASE3), remote sense inputs (VSNSP/VSNSN), serial bus pins (SCL/SDA), and programmable analog inputs (IMON, THERM, FREQSET).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PHASE1–PHASE3 | High-side/low-side gate driver outputs | Direct drive of external MOSFET half-bridges in 1–3-phase VR topology |
| VSNSP / VSNSN | Differential remote voltage sense inputs | Enable precise core voltage regulation at CPU pads, rejecting PCB IR drop |
| SCL / SDA | VR12.5™ serial bus interface | Two-wire bidirectional communication with CPU for VID, status, and power-state commands |
| IMON | Current monitor input | Accepts DCR voltage or resistor-based current signal for real-time load reporting |
| THERM | NTC thermistor input | Compensates DCR resistance drift with temperature using single NTC network |
| FREQSET | Switching frequency programming pin | Resistor-to-ground sets nominal switching frequency (default ~300 kHz) |
Key Features
| Feature | Design Value |
|---|---|
| Phase shedding with power state selection | Reduces active phases under light load to cut switching losses and improve efficiency |
| Diode emulation mode in single-phase | Disables synchronous rectification to emulate body-diode conduction, eliminating reverse recovery losses |
| Adaptive body diode conduction time reduction | Minimizes dead-time-induced shoot-through risk while preserving efficiency in high-frequency operation |
| Programmable voltage transition slew rate | Controls dV/dt during VID transitions to prevent CPU reset or instability during power-state changes |
| Adjustable overcurrent protection threshold | Resistor-programmable IMAX limit ensures robust short-circuit protection without sacrificing transient headroom |
Applications
| Desktop CPU Core VR | VR12.5 Compliant Motherboard |
|---|---|
Use Scenario: Power delivery to Intel Core i5/i7 processors in ATX desktop platforms requiring dynamic VID scaling and multi-phase efficiency. IC Role / Device Role / Timing Role: Primary PWM controller managing phase count, current sharing, and serial CPU communication. Use Value: Enables VR12.5 compliance with <0.5% voltage error, phase shedding, and fast transient response (<1 µs) to CPU load steps. | Use Scenario: Integrated into motherboard VRM design with discrete MOSFETs and chokes, supporting BIOS-controlled power states. IC Role / Device Role / Timing Role: Central VR controller coordinating gate drive timing, current sensing, and thermal compensation. Use Value: Reduces board area via serial bus (vs parallel VID), eliminates need for external DAC, and supports DCR-based current sensing with single NTC. |
| Multi-Phase VR Reference Design | High-Efficiency Desktop PSU Module |
Use Scenario: Used in reference designs for 3-phase VRMs targeting >90% full-load efficiency and sub-100 µs load-step recovery. IC Role / Device Role / Timing Role: R3™ modulator core providing variable-frequency control and adaptive dead-time management. Use Value: Achieves faster transient response than fixed-frequency controllers and maintains stability across wide input/output ranges (12 V input, 0.5–1.5 V output). | Use Scenario: Embedded in compact VRM modules for OEM pre-built systems where thermal and layout constraints demand high integration. IC Role / Device Role / Timing Role: Single-chip solution integrating drivers, sensing interface, and serial protocol logic. Use Value: Eliminates need for separate driver ICs and current-sense amplifiers, reducing BOM count and enabling 7 mm × 7 mm footprint. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar three-phase VR controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| IR35201MTRPBF | Supports VR12/VR12.5/VR13; includes digital telemetry and PMBus interface instead of serial bus | Used in server/workstation VRMs requiring telemetry logging and firmware-updatable parameters | Choose IR35201MTRPBF when digital monitoring, fault logging, or PMBus host control is required |
| RT8803AZQW | Single-chip 3-phase controller with integrated drivers but no VR12.5 serial bus; uses analog VID pins | Targeted at cost-sensitive mainstream desktop boards without CPU serial bus dependency | Choose RT8803AZQW when VR12.5 compliance is not required and analog VID interface suffices |
Compared with IR35201MTRPBF and RT8803AZQW, the ISL95821CRTZ-T uniquely delivers native VR12.5 serial bus support with R3™ modulation, offering superior transient response and simpler system integration for Intel desktop CPUs - without PMBus overhead or analog VID pin count penalties.
Availability
ISL95821CRTZ-T is available at Aetrix Electronics and suitable for desktop CPU VRMs, motherboard power delivery systems, and Intel VR12.5™-compliant embedded computing platforms requiring stable component supply and long-term lifecycle support.
Supply support for ISL95821CRTZ-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
Renesas Electronics acquired Intersil in 2017 and continues to support its high-performance analog and power management portfolio for computing and industrial applications.
The ISL95821CRTZ-T belongs to Renesas' VR controller product line, engineered specifically for Intel VR12.5™ microprocessor core power delivery with emphasis on transient performance, integration, and thermal-aware current sensing.
FAQ
What is the primary function of the ISL95821CRTZ-T in a CPU power delivery system?
The ISL95821CRTZ-T serves as the core three-phase PWM controller for Intel VR12.5™-compliant CPU voltage regulators. It manages gate drive timing, current sensing, phase shedding, and serial communication with the CPU via the VR12.5™ bus. Its R3™ modulator ensures fast transient response and high light-load efficiency - essential for modern desktop processor power integrity. The ISL95821CRTZ-T directly controls external MOSFETs and supports both DCR and resistor-based current sensing methods.
Does the ISL95821CRTZ-T support remote voltage sensing, and why is it important?
Yes, the ISL95821CRTZ-T features differential remote voltage sensing (VSNSP/VSNSN pins) to measure CPU core voltage directly at the load point. This compensates for IR drop across PCB traces and improves regulation accuracy to ±0.5% over temperature and load. Remote sensing is critical for VR12.5™ compliance, as tight voltage tolerances must be maintained at the CPU die - not just at the VRM output. The ISL95821CRTZ-T uses this feedback to dynamically adjust duty cycle and maintain stable core power under rapid load transients.
How does the R3™ modulator in the ISL95821CRTZ-T improve transient response compared to traditional PWM controllers?
The R3™ modulator in the ISL95821CRTZ-T achieves faster transient response by varying switching frequency in real time based on load step magnitude and direction - unlike fixed-frequency controllers that rely solely on loop gain. It also enables diode emulation and adaptive dead-time control to reduce body diode conduction losses. These features allow the ISL95821CRTZ-T to recover from large load steps (<1 µs) while maintaining stability. The R3™ architecture is integral to the ISL95821CRTZ-T's ability to meet Intel VR12.5™ transient specifications without external compensation components.
Can the ISL95821CRTZ-T operate in single-phase mode, and what benefit does that provide?
Yes, the ISL95821CRTZ-T supports configurable 1-, 2-, or 3-phase operation via external pin strapping or serial bus command. In single-phase mode, it activates diode emulation to disable synchronous rectification and emulate body-diode conduction - significantly improving light-load efficiency by eliminating reverse recovery losses. This mode is automatically engaged during low-power CPU states (e.g., C-states), and the ISL95821CRTZ-T manages the transition seamlessly. Phase shedding and reactivation are fully controlled by the ISL95821CRTZ-T without host intervention.
What current sensing methods does the ISL95821CRTZ-T support, and how is temperature compensation handled?
The ISL95821CRTZ-T supports both lossless DCR current sensing (using inductor resistance) and precision resistor-based sensing. For DCR sensing, it accepts a single NTC thermistor connected to the THERM pin to compensate for copper resistance drift over temperature - ensuring accurate current reporting across the full operating range. Resistor sensing bypasses DCR drift entirely but requires additional power dissipation. Both methods feed into the ISL95821CRTZ-T's IMON input, which the controller uses for overcurrent protection, phase balancing, and telemetry. No external op-amps or ADCs are needed.
ISL95821CRTZ-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- Robust Ripple Regulator™ (R3)
- Package/Case:
- 40-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Applications:
- Controller, Intel VR12.5
- Voltage - Input:
- 4.5V ~ 28V
- Number of Outputs:
- 1
- Voltage - Output:
- 0.5V ~ 2.3V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 40-TQFN (5x5)
ISL95821CRTZ-T FAQ
1.How can I place an order for ISL95821CRTZ-T through Aetrix?
Please submit a Request for Quotation (RFQ) for ISL95821CRTZ-T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ISL95821CRTZ-T reliable?
The price and inventory of ISL95821CRTZ-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISL95821CRTZ-T is usually 5 days.
3.What payment methods are accepted for ISL95821CRTZ-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISL95821CRTZ-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISL95821CRTZ-T?
ISL95821CRTZ-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISL95821CRTZ-T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ISL95821CRTZ-T?
For technical support, including ISL95821CRTZ-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISL95821CRTZ-T requirements.
6.How does Aetrix verify that ISL95821CRTZ-T is sourced from the original manufacturer or authorized distributors?
All ISL95821CRTZ-T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ISL95821CRTZ-T meets industry standards.
7.What is the process for return or replacement of ISL95821CRTZ-T?
All ISL95821CRTZ-T units undergo pre-shipment inspection (PSI). If there is an issue with ISL95821CRTZ-T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ISL95821CRTZ-T part is unused and in its original packaging.
Return procedure for ISL95821CRTZ-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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