Compute Rack - Block Diagram

High-voltage ±400V/800V DC power architecture for AI compute racks, converting HVDC bus power to regulated loads with isolation, control, protection, power distribution, and communication functions for data center AI accelerators.

"longDescription": "Detailed Description of Each Block", "blocks": [ { "name": "HVDC Bus Bar", "function": "High voltage DC power source distributing ±400 V or 800 V DC throughout the compute rack power architecture.", "theory_of_operation": "Provides a stable high-voltage DC distribution backbone feeding the front-end power conversion stages and auxiliary power circuitry.", "interaction": "Supplies power to the LLC Resonant Converter and Auxiliary Power Supply.", "category": "Third party", "connection": [ "LLC Resonant Converter", "Auxiliary Power Supply" ] }, { "name": "LLC Resonant Converter", "function": "High-efficiency isolated DC-DC conversion stage generating the main intermediate bus voltage.", "theory_of_operation": "Uses resonant tank components and transformer isolation to achieve soft-switching operation, reducing switching losses and enabling efficient conversion of HVDC to the Main Vbus.", "interaction": "Receives power from Input, is controlled through the Isolated Gate Driver, and provides power to Main Vbus.", "connection": [ "Power Distribution", "Sensing & Isolation" ] }, { "name": "Sensing & Isolation", "function": "Measures voltage and current while providing galvanic isolation between high-voltage and low-voltage domains.", "theory_of_operation": "Uses isolated sensing technologies to transfer measurement information across safety isolation barriers.", "interaction": "Monitors Input and Main Vbus and exchanges information with the Auxiliary Power Supply.", "category": "onsemi", "connection": [ "Controller" ] }, { "name": "Isolated Gate Driver", "function": "Provides isolated drive signals for primary-side power switches in the LLC converter.", "theory_of_operation": "Receives low-voltage PWM control signals and generates appropriate gate-drive voltages while maintaining isolation.", "interaction": "Interfaces between Auxiliary Power Supply, Galvanic Isolation, and LLC Resonant Converter.", "category": "onsemi", "connection": [ "LLC Resonant Converter" ] }, { "name": "Power Distribution", "function": "Distributes intermediate bus power to AI processing loads.", "theory_of_operation": "Uses hot-swap and multi-phase regulation stages to safely manage high-current delivery to processors.", "interaction": "Receives Main Vbus and supplies the AI load.", "connection": [ "AI Processor" ], "sub_blocks": [ { "name": "Point of Load", "function": "Final voltage regulation for AI devices.", "theory_of_operation": "Converts intermediate bus voltage into low-voltage, high-current rails required by processors.", "interaction": "Works with Multi-Phase Control to supply the AI Processor.", "category": "onsemi", "connection": [] }, { "name": "Multi-Phase Control", "function": "Controls multiple power phases for high-current regulation.", "theory_of_operation": "Interleaves switching phases to reduce ripple current and improve efficiency.", "interaction": "Controls Point of Load regulators.", "category": "onsemi", "connection": [] }, { "name": "Hot Swap", "function": "Provides controlled connection of power modules to the live bus.", "theory_of_operation": "Limits inrush current and protects system components during insertion and startup.", "interaction": "Operates on the Main Vbus before power reaches downstream loads.", "category": "onsemi", "connection": [] } ] }, { "name": "AI Processor", "function": "Computational accelerator executing AI workloads.", "theory_of_operation": "Consumes regulated power rails and performs AI model processing and inference tasks.", "interaction": "Receives power from Point of Load regulators and communicates with the controller subsystem.", "category": "Third party", "connection": [] }, { "name": "Auxiliary Power Supply", "function": "Generates low-voltage rails and support functions for system control and monitoring.", "theory_of_operation": "Derives low-voltage power from the HVDC bus using switching and linear regulation stages.", "interaction": "Supplies support circuitry, communications, sensing blocks, and gate drivers.", "connection": [ "Support Circuitry", "Communication", "Sensing & Isolation", "Isolated Gate Driver" ], "sub_blocks": [ { "name": "PWM Controller", "function": "Controls switching power conversion stages.", "theory_of_operation": "Generates pulse-width modulated drive signals to regulate output voltages.", "interaction": "Controls MOSFET switching activity.", "category": "onsemi", "connection": [] }, { "name": "DC/DC Converter", "function": "Converts input voltage to required intermediate low-voltage rails.", "theory_of_operation": "Uses high-frequency switching conversion for efficient voltage transformation.", "interaction": "Provides power to downstream regulators and support circuits.", "category": "onsemi", "connection": [] }, { "name": "MOSFET", "function": "Primary switching element for auxiliary converters.", "theory_of_operation": "Operates as a high-efficiency electronic switch controlled by the PWM Controller.", "interaction": "Works with the PWM Controller and DC/DC Converter.", "category": "onsemi", "connection": [] }, { "name": "Diode", "function": "Rectification and protection element.", "theory_of_operation": "Allows current flow in one direction and blocks reverse current.", "interaction": "Supports auxiliary power conversion stages.", "category": "onsemi", "connection": [] }, { "name": "LDO", "function": "Provides low-noise regulated supply rails.", "theory_of_operation": "Uses linear regulation to maintain precise output voltage.", "interaction": "Supplies sensitive digital and analog circuitry.", "category": "onsemi", "connection": [] }, { "name": "Aux. Support Circuitry", "function": "Additional circuitry supporting power-supply operation and protection.", "theory_of_operation": "Provides monitoring, startup, sequencing, and protection functionality.", "interaction": "Works with all auxiliary power stages.", "category": "onsemi", "connection": [] } ] }, { "name": "Support Circuitry", "function": "Controller-support subsystem providing memory, logic, monitoring, and analog functions.", "theory_of_operation": "Provides storage, monitoring, timing, reference generation, and signal conditioning for system management.", "interaction": "Interfaces bidirectionally with the controller.", "connection": [ "Controller" ], "sub_blocks": [ { "name": "Memory", "function": "Stores firmware, configuration, and operational data.", "theory_of_operation": "Retains and retrieves digital information for controller operation.", "interaction": "Connected to Controller.", "category": "onsemi", "connection": [] }, { "name": "Standard Logic", "function": "Provides digital logic functions.", "theory_of_operation": "Implements combinational and sequential logic operations.", "interaction": "Supports Controller operations.", "category": "onsemi", "connection": [] }, { "name": "Voltage Reference", "function": "Provides precision reference voltages.", "theory_of_operation": "Generates stable voltage independent of supply variation.", "interaction": "Supports monitoring and regulation functions.", "category": "onsemi", "connection": [] }, { "name": "Voltage Supervisor", "function": "Monitors power rails and reset conditions.", "theory_of_operation": "Detects undervoltage or fault conditions and initiates corrective actions.", "interaction": "Protects Controller operation.", "category": "onsemi", "connection": [] }, { "name": "Small Signal", "function": "Analog signal conditioning and interface circuitry.", "theory_of_operation": "Processes low-level analog signals for monitoring and control.", "interaction": "Interfaces with Controller.", "category": "onsemi", "connection": [] }, { "name": "BJT & BRT", "function": "Discrete transistor functions and biasing circuits.", "theory_of_operation": "Provides amplification, switching, and bias control functions.", "interaction": "Supports Controller and auxiliary circuits.", "category": "onsemi", "connection": [] } ] }, { "name": "Controller", "function": "Central system controller and management processor.", "theory_of_operation": "Coordinates monitoring, communications, and power-management activities.", "interaction": "Communicates bidirectionally with Support Circuitry and Communication subsystem.", "category": "Third party", "connection": [ "Support Circuitry", "Communication" ] }, { "name": "Communication", "function": "Network connectivity and interface protection.", "theory_of_operation": "Provides external communication links while protecting interfaces from electrical disturbances.", "interaction": "Communicates bidirectionally with the Controller.", "connection": [ "Controller" ], "sub_blocks": [ { "name": "Ethernet", "function": "High-speed wired communication interface.", "theory_of_operation": "Transfers digital data over Ethernet network infrastructure.", "interaction": "Connects Controller to external systems.", "category": "onsemi", "connection": [] }, { "name": "ESD Protection", "function": "Protects communication interfaces against electrostatic discharge.", "theory_of_operation": "Clamps transient voltages and diverts surge currents away from sensitive circuitry.", "interaction": "Protects Ethernet interfaces.", "category": "onsemi", "connection": [] } ] } ], "interconnections": [ { "source": "HVDC Bus Bar", "target": "LLC Resonant Converter" }, { "source": "Isolated Gate Driver", "target": "LLC Resonant Converter" }, { "source": "LLC Resonant Converter", "target": "Power Distribution" }, { "source": "LLC Resonant Converter", "target": "Sensing & Isolation" }, { "source": "Power Distribution", "target": "AI Processor" }, { "source": "HVDC Bus Bar", "target": "Auxiliary Power Supply" }, { "source": "Auxiliary Power Supply", "target": "Sensing & Isolation" }, { "source": "Auxiliary Power Supply", "target": "Isolated Gate Driver" }, { "source": "Auxiliary Power Supply", "target": "Support Circuitry" }, { "source": "Auxiliary Power Supply", "target": "Communication" }, { "source": "Sensing & Isolation", "target": "Controller" }, { "source": "Support Circuitry", "target": "Controller" }, { "source": "Controller", "target": "Support Circuitry" }, { "source": "Communication", "target": "Controller" }, { "source": "Controller", "target": "Communication" } ], "Last_update": "2026-10-06",

PWM Control - Block

製品

• オフライン・コントローラ
  • NCP1251

    PWMコントローラ、電源モード、オフライン電源用

  • NCP1362

    プライマリ・サイド PWM コントローラ (低電力オフライン SMPS 用)

  • NCP1345

    Highly integrated quasi-resonant flyback controller for off-line USB-PD and USB Type-C power converters.

  • NCP1568

    AC-DCアクティブ・クランプ・フライバックPWMコントローラ

• オフライン・レギュレータ
  • NCP11184

    Enhanced standby mode 2.25Ω, 800 V Switcher

  • NCP11185

    Enhanced standby mode 1.3 Ω, 800 V Switcher

  • NCP11187

    Enhanced standby mode 0.87 Ω, 800 V Switcher

  • NCP1072

    高電圧スイッチング・レギュレータ (オフライン SMPS 対応)

  • NCP1076

    高電圧スイッチング・レギュレータ (オフライン SMPS 対応)

• 二次側コントローラ
  • NCP4307

    Secondary Side Synchronous Rectification Driver with Dual Supply

  • NCP4306

    セカンダリ・サイド同期整流ドライバ（高効率SMPSトポロジ用）

技術文書

• Application Notes
  • AND8486/D - A 12V/40W Demonstrator with NCP1250
  • AND8488/D - Tips and Tricks for NCP1250
  • AND8469/D - The NCP1250, a Versatile Tiny Controller for Offline Converters
  • AND8468/D - A 60 W ac-dc Demonstrator with NCP1250
  • AND8453/D - Loop Control Design of an ac-dc Adapter Using the NCP1250
  • AND9890/D - A High Voltage Input Supply 12 W Adaptor with NCP1362 Primary Side Regulated Quasi Resonant Controller
  • AND90024/D - Designing a PSR Quasi-Resonant Adaptor Driven by the NCP1362
  • AND90025/D - A 12 W Adaptor with NCP1362 Quasi Resonant Controller
• Collateral Brochure
  • BRD8093/D - Power Supply Solutions
• Conformance Report
  • TND6383/D - IEC62368-1 ICX certificate for NCP1618, 1345 and 13994 series.
• Data Sheet
  • NCP1251/D - Controller, Current Mode PWM, for Offline Power Supplies
  • NCP1362/D - Primary Side PWM Controller for Low Power Offline SMPS
  • NCP1345/D - High-Voltage Quasi-Resonant Flyback Controller With USB-PD Optimization
  • NCP1568/D - AC-DC Active Clamp Flyback PWM IC
  • NCP11184/D - mWSaver® Integrated Power Switcher with 800 V SJ MOSFET for Offline SMPS
  • NCP1070/D - High-Voltage Switcher for Low Power Offline SMPS
  • NCP4307/D - Secondary Side Synchronous Rectification Driver for High Efficiency SMPS Topologies
  • NCP4306/D - Secondary Side Synchronous Rectification Driver for High Efficiency SMPS Topologies
• Design & Development Tools
  • FLYBACK DWS.XLS.ZIP - Flyback Current Mode Loop Compensation Design Worksheet
  • FLYBACK TRANSFORMER DESIGN TOOL - Flyback Transformer Design Tool
  • NCP/NCV1362 Design Worksheet - MathCad - NCP/NCV1362 Design Worksheet (AC input) - MathCad
  • NCP/NCV1362 Design Worksheet (DC input) - MathCad - NCP/NCV1362 Design Worksheet (DC input) - MathCad
  • AC-DC Active Clamp Flyback Design Tool_XMCD - AC-DC Active Clamp Flyback Design Tool_XMCD
  • AC-DC ACF Design Tool - AC-DC Active Clamp Flyback Design Tool
  • NCP1118x Family Excel-based Design Tool - NCP1118x Family Excel-based Design Tool
• Design Notes
  • DN05012/D - NCP1251: 20 W Output Offline Power Supply
  • DN05039/D - NCP1251: Ultra Wide Input Triple Output 15 W (E-Meter)
  • DN05017/D - NCP1251: Low Power, Ultra-Wide AC Input Range, Electric Meter Power Supply
  • DN05028/D - NCP1251: 20 W Output Offline Power Supply Using Synchronous Output Rectification
  • DN05032/D - NCP1251: A 24 Vin, 40 Watt, Low Cost, DC-to-DC Converter
  • DN05029/D - NCP1251: 12 V, 30 W, Off-line Mini-Forward Converter
  • DN05033/D - NCP1251: 20 W Flyback with Primary Side Regulation (PSR)
  • DN05119 - NCP1568 60-W Ultra-High Density USB-PD Laptop Adapter
  • DN05125/D - NCP1568 90W TYPE-C PD3.0 / QC4.0 Power Adapter
  • DN05114/D - NCP1568 60-W USB-PD Eval Board Design Note
  • DN05058/D - NCP1071, NCP1075, MCP1077: 12 Vout, Off-line Buck Regulator
  • DN05036/D - NCP1072: 10 W Primary Side Regulation (PSR)
  • DN05018/D - NCP1075: Universal AC Input, 12 Vout,10 W E-Meter Power Supply
  • DN05049/D - NCP1076/7: Universal Input, 5 V or 12 V Output, up to 24 W Power Supply
  • DN05105/D - USB-C, PD3.0/QC3.0, 30 W Power Adapter Solution
  • DN05102/D - USB-C, PD3.0/QC3.0, 45 W Power Adapter Solution
  • DN05104/D - USB-C, PD3.0/QC3.0, 45 W Power Adapter Solution
• Drawing
  • NCP1251_MS - NCP1251_MS | Marking Spec
  • NCP1251_PD - NCP1251_PD | Package Drawing
  • NCP1251_PO - NCP1251_PO | Pin Out
  • NCP1251_AD - NCP1251_AD | Application Diagram
  • NCP1072_MS - NCP1072_MS | Marking Spec
  • NCP1072_PO - NCP1072_PO | Pin Out
  • NCP1072_AD - NCP1072_AD | Application Diagram
• Eval Board
  • NCP_NCV1362_SCHEMATIC - NCP_NCV1362_SCHEMATIC.rev0 | Schematic
  • NCV1362WGEVB_GERBER - NCV1362WGEVB_GERBER.rev0 | Gerber
  • NCV1362WGEVB_TEST_PROCEDURE - NCV1362WGEVB_TEST_PROCEDURE.rev0 | Test Procedure
  • NCV1362WGEVB_BOM_ROHS - NCV1362WGEVB_BOM_ROHS.rev0 | BOM
  • EVBUM2819/D - 65 W TYPE-C PD3.0 / PPS Charger Solution with FUSB15101 Evaluation Board User's Manual | Manual
  • NCP1345PD65WGEVB_SCHEMATIC.pdf - NCP1345PD65WGEVB Schematic | Schematic
  • NCP1345PD65WGEVB_GERBER.zip - NCP1345PD65WGEVB Gerber Layout Files (Zip Format) | Gerber
  • EVBUM2751/D - 25 W Auxiliary Power Supply for White Goods and Industrial Equipment with NCP11184A65 | Manual
  • EVBUM2755/D - 38 W Auxiliary Power Supply for White Goods and Industrial Equipment with NCP11185A130 | Manual
  • EVBUM2740/D - 45 W Auxiliary Power Supply for White Goods and Industrial Equipment with NCP11187A65 | Manual
  • NCP1072DIPGEVB_SCHEMATIC.PDF - NCP1072DIPGEVB Schematic | Schematic
  • NCP1072DIPGEVB_GERBER.ZIP - NCP1072DIPGEVB Gerber Layout Files (Zip Format) | Gerber
  • NCP1072DIPGEVB_TEST_PROCEDURE.PDF - NCP1072DIPGEVB Test Procedure | Test Procedure
  • NCP1072DIPGEVB_BOM_ROHS.PDF - NCP1072DIPGEVB Bill of Materials ROHS Compliant | BOM
  • EVBUM2520/D - NCP4306 Synchronous Rectification Evaluation Board User's Manual | Manual
  • EVBUM2522/D - NCP4306 Synchronous Rectification Evaluation Board User's Manual | Manual
  • EVBUM2521/D - NCP4306 Synchronous Rectification Evaluation Board User's Manual | Manual
  • EVBUM2684/D - GaN Based Ultra-high Power Density Adapter 300W | Manual
• Models
  • NCP1250_ORCAD_MODEL - OrCAD Models for NCP1250
  • NCP1250_FLYBACK_CIRCUIT - ICAPS Flyback Drawing with NCP1250
  • NCP/NCV1362 Simplis - Simplis Model
  • NCP1118x Family Simplis Behavior Model - NCP1118x Family Simplis Behavior Model
  • NCP107x SIMPLIS - AC and TRAN analyses of NCP107x-based circuits
  • NCP1075 ISpice Model - ICAPS Flyback drawing wxith NCP107x
  • NCP4307 Active Clamp Flyback - NCP4307 Active Clamp Flyback
  • NCP4307 Active Clamp Forward - NCP4307 Active Clamp Forward
  • NCP4307 Flyback - NCP4307 Flyback
  • NCP4306AADZZZA SIMPLIS - NCP4306AADZZZA SIMPLIS
  • NCP4306AAAZZZA SIMPLIS - NCP4306AAAZZZA SIMPLIS
  • NCP4306AAHZZZA SIMPLIS - NCP4306AAHZZZA SIMPLIS
• Package Drawing
  • 318G-02 - TSOP-6 3.00x1.50x0.90, 0.95P
  • 751-07 - SOIC-8 Narrow Body
  • 751BP - SOIC9 NB
  • 948BW - TSSOP16 MINUS PINS 2,3,14 & 15
  • 626A-01 - PDIP-7 (PDIP-8 LESS PIN 6)
  • 318E-04 - SOT-223 (TO-261) 4 LEAD
  • 506BP - DFN8 2.0x2.2, 0.5P
  • 488AF - 8 PIN DFN, 4x4
• Reference Designs
  • TND6458/D - 240 W USB PD3.1 EPR - CrM Totempole PFC and 2 Switch Flyback Solution
  • TND6457/D - 240 W UHD Power Supply - CrM Totempole PFC and Current Mode LLC HB Solution
• Simplis Models
  • NCP1568 SIMplis - NCP1568 SIMplis Model
• System Solution Guide
  • SSG8202/D - Switched-Mode Power Supply (SMPS)
  • SSG8204/D - Solar Inverter
  • SSG8207/D - Ultra Fast EV Charger
  • SSG8208/D - Battery Energy Storage System
  • SSG8227/D - Green Hydrogen Electrolyzer
  • SSG8222/D - USB-C Battery Charger
  • SSG8233/D - Telecom Base Stations
  • SSG8215/D - Battery-powered Tools
  • SSG8203/D - Heat Pumps
  • SSG8209/D - Uninterruptible Power Supply (UPS)
  • SSG8226/D - AI Data Center
  • SSG8210/D - Smart and Mobile Robotics
  • SSG8216/D - Industrial Motor Drive
• Tutorial
  • WVD17004/D - Smart Metering - Power Management &Power Line Communications
  • TND6280/D - High-Density Ac-Dc Power Supplies using Active-Clamp Flyback
  • WVD17003/D - Smart Metering Overview
• Video
  • TND6122/D - Low Cost, High Performance Off-Line Flyback 25 W Power Supply - NCP1251GEVB
  • WVD17951/D - Ultra High-Power Density USB-PD Charger with Extended Power Range (EPR)
  • WVD17249/D - High Density USB-PD Adapter Solution - Active Clamp Flyback PWM Controller Demonstration
  • WVD17580/D - 6 W Switched-Mode Power Supply Evaluation Board - NCP1072DIPGEVB
  • WVD17599/D - 20W High Voltage Switching Regulator for Offline SMPS Evaluation Board - NCP1076DIPGEVB
  • WVD18076/D - Webinar - 12kW Power Supply Design with CJFETs in AI Data Centers
  • WVD17362/D - 300 W Ultra High Density Adapter for Gaming Notebooks and OLED TVs
• White Papers
  • TND6448/D - Popular Topologies in Offline Power Supplies
  • TND6279/D - High‐Density AC-DC Power Supplies using Active-Clamp Flyback Topology

Evaluation Boards/Kits

• NCP1345PD65WGEVB

  NCP1345 USB-PD 65W Evaluation Board.

• NCV1362WGEVB

  Primary Side PWM Controller 12-V/1-A Evaluation Board

FAQs