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| LTC2975四路PMBus電源系統管理方案 |
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| 文章來源： 更新時間：2014/12/6 11:06:00 |
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Linear公司的LTC2975是四路PMBus電源系統管理器,具有精確的輸入電流和能量測量,用來確序,調整(伺服),留余量,監測,管理故障,和提供遙測和創建故障記錄.I2C/SMBus串口, 3.3V或4.5V-15V供電,主要用在計算機和網絡服務器,工業測試和測量,高可靠系統,視頻和醫療圖像.本文介紹了LTC2975主要特性,框圖和應用電路,以及評估系統DC2022A 主要特性, 簡化框圖,電路圖和材料清單,PCB元件布局圖.
The LTC®2975 is a 4-channel Power System Manager used to sequence, trim (servo), margin, supervise, manage faults, provide telemetry and create fault logs. PMBus commands support power supply sequencing, precision point-of-load voltage adjustment and margining. DACs use a proprietary soft-connect algorithm to minimize supply disturbances. Supervisory functions include over and under current, voltage and temperature threshold limits for four power supply output channels as well as over and under voltage threshold limits for a single power supply input channel. Programmable fault responses can disable the power supplies with optional retry after a fault is detected.
Faults that disable a power supply can automatically trigger black box EEPROM storage of fault status and associated telemetry. An internal 16-bit ADC monitors four output voltages, four output currents, four external temperatures, input voltage and current, and die temperature. Input power, energy, and output power is also calculated. A programmable watchdog timer monitors microprocessor activity for a stalled condition and resets the microprocessor if necessary. A single wire bus synchronizes power supplies across multiple LTC Power System Management (PSM) devices. Configuration EEPROM supports autonomous operation without additional software.
LTC2975主要特性:
Sequence, Trim, Margin and Supervise Four Power Supplies
Manage Faults, Monitor Telemetry and Create Fault Logs
PMBus™ Compliant Command Set
Supported by LTpowerPlay™ GUI
Margin or Trim Supplies to Within 0.25% of Target
Monitor Input Current (±1%) and Accumulate Energy
Fast OV/UV and OC Supervisors Per Channel
Coordinate Sequencing and Fault Management Across Multiple LTC PSM Devices
Automatic Fault Logging to Internal EEPROM
Operate Autonomously Without Additional Software
External Temperature and Input Voltage Supervisors
Accurate Monitoring of Four Output Voltages, Four Output Currents, Four External Temperatures, Input Voltage and Current, and Internal Die Temperature
I2C/SMBus Serial Interface
Can Be Powered from 3.3V, or 4.5V to 15V
Pin-Compatible to the LTC2974
Available in 64-Lead 9mm . 9mm QFN Package
LTC2975應用:
Computers and Network Servers
Industrial Test and Measurement
High Reliability Systems
Video and Medical Imaging
圖1. LTC2975框圖
圖2. LTC2975帶輸入能量測量的四路PMBus電源系統管理器電路
圖3. LTC2975中轉總線Crowbar保護的應用電路
LTCR2975評估系統DC2022A
The DC2022A is a demonstration system that showcases the LTCR2975, a 4-channel I2C/SMBus/PMBus power system manager with EEPROM. The LTC2975 monitors and controls four power supply rails. The LTC2975 also monitors input current and input voltage, which are used to calculate input power and accumulate energy. The DC2022A demonstrates the ability of the LTC2975 to sequence, trim, margin, supervise, monitor, and log faults for four power supplies. Each power supply channel’s output voltage is monitored and the LTC2975 monitors its own internal die temperature.
The DC2022A is a single circuit board that contains four independent power supply rails. The board employs four LTC3405A 300mA switch-mode regulators, which are configured to be controlled by the LTC2975. The DC2022A demo board provides a sophisticated 4-channel digitally programmable power supply system. The rail voltages are programmable within the trim range shown in the Performance Summary table.
This demonstration system is supported by the LTpowerPlay™ graphical user interface (GUI) which enables complete control of all the features of the device. Together, the LTpowerPlay software and DC2022A hardware system create a powerful development environment for designing and testing configuration settings of the LTC2975. These settings can be stored in the device’s internal EEPROM or in a file. This file can later be used to order pre-programmed devices or to program devices in a production environment.
The software displays all of the configuration settings and real time measurements from the power system management IC. Telemetry allows easy access and decoding of the fault log created by the LTC2975. The board comes pre-programmed with the EEPROM values appropriate for the four power supply rails on the DC2022A.
Just plug and play!
Multiple DC2022A boards can be cascaded together to form a high channel count power supply (see the Multi-Board Arrays section). This cascaded configuration demonstrates features of the LTC Power System Management ICs which enable timing and fault information to be shared across multiple power system management ICs. The user can configure up to eight DC2022A boards, thereby controlling up to 32 separate power supply rails. Larger board arrays can be built using programmable I2C base addresses or bus segmentation.
The DC2022A demo board can be powered by an external power supply, such as a +12VDC supply. Communication with the software is provided through the DC1613 USB-to- I2C/SMBus/PMBus Controller.
評估系統DC2022A 主要特性:
Sequence, Trim, Margin, and Supervise Four Power Supplies
Manage Faults, Monitor Telemetry, and Create Faul Logs
PMBus Compliant Command Set
Supported by LTpowerPlay GUI
Margin or Trim Supplies to 0.25% Accuracy
Four IOUT and One IIN Monitor
Input Power Measurement and Energy Accumulation
Fast OV/UV Supervisors per Channel
Supports Multi-Channel Fault Management
Automatic Fault Logging to Internal EEPROM
Operates Autonomously without Additional SW
Telemetry Reads Back VIN, VOUT, and Temperature
4-Channel Time-Based Output Sequencer
I2C/SMBus Serial Interface
Powered from 6V to 14V
LTC2975 Available in 64-Lead QFN Package
圖4. 評估系統DC2022A外形圖(頂層)
圖5. 多個評估系統DC2022A連接圖
圖6. 評估系統DC2022A簡化框圖
圖7. 評估系統DC2022A電路圖(1)
圖8. 評估系統DC2022A電路圖(2)
圖9. 評估系統DC2022A電路圖(3)
圖10. 評估系統DC2022A電路圖(4)
評估系統DC2022A材料清單:
圖11. 評估系統DC2022A PCB元件布局圖:頂層
圖12. 評估系統DC2022A PCB元件布局圖:底層 |
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