新聞中心

        EEPW首頁 > 電源與新能源 > 設計應用 > ADIADM12752V-20V熱插拔控制方案

        ADIADM12752V-20V熱插拔控制方案

        作者: 時間:2012-03-14 來源:網絡 收藏
        ADI公司的ADM1275是2V-20V的控制器,能使電路板插入或拔出帶電背板,控制電源電壓為2V-20V,限流電阻可編程從5mV到25mV,12位的精度為±1%,電荷泵柵極驅動器用來驅動多個外接N-溝FET,高柵極驅動電壓保證了最低的RDSON,主要用在電源監視,電訊和數據通信設備,PC/服務器等.本文介紹了ADM1275主要特性,方框圖,以及評估板EVAL-ADM127xEBZ主要特性,電路圖,材料清單和PCB布局圖.

        The ADM1275 is a hot-swap controller that allows a circuit board to be removed from or inserted into a live backplane. It also features current and voltage readback via an integrated 12-bit analog-to-digital converter (), accessed using a PMBus? interface.

        The load current is measured using an internal current sense amplifier that measures the voltage across a sense resistor in the power path via the SENSE+ and SENSE? pins. A default limit of 20 mV is set, but this limit can be adjusted, if required, using a resistor divider network from the internal reference voltage to the ISET pin.

        The ADM1275 limits the current through the sense resistor by controlling the gate voltage of an external N-channel FET in the power path, via the GATE pin. The sense voltage—and, therefore, the load current—is maintained below the preset maximum. The ADM1275 protects the external FET by limiting the time that the FET remains on while the current is at its maximum value. This current limit time is set by the choice of capacitor connected to the TIMER pin. In addition, a foldback resistor network can be used to actively lower the current limit as the voltage across the FET is increased. This helps to maintain constant power in the FET and allows the safe operating area (SOA) to be adhered to in an effective manner.

        In case of a short-circuit event, a fast internal overcurrent detec-tor responds within 370 ns and signals the gate to shut down. A 1500 mA pull-down device ensures a fast FET response. The ADM1275 features overvoltage and undervoltage protection, programmed using external resistor dividers on the UV and OV pins. A PWRGD signal can be used to detect when the output supply is valid, using the FLB pin to monitor the output. GPO pins can be configured as various output signals that can be asserted when a programmed current or voltage level is reached.

        The 12-bit can measure the current in the sense resistor, as well as the supply voltage on the SENSE+ pin or the output voltage. A PMBus interface allows a controller to read current and voltage data from the ADC. Measurements can be initiated by a PMBus command. Alternatively, the ADC can run continu-ously, and the user can read the latest conversion data whenever required. Up to four unique PMBus addresses can be selected, depending on the way that the ADR pin is connected.

        The ADM1275-1 and ADM1275-3 are available in a 20-lead QSOP and 20-lead LFCSP and have a LATCH pin that can be configured for automatic retry or latch-off when an overcurrent fault occurs. The ADM1275-2 is available in a 16-lead QSOP with latch-off mode only.

        ADM1275主要特性:

        Controls supply voltages from 2 V to 20 V

        370 ns response time to short circuit

        Resistor-programmable 5 mV to 25 mV current limit

        ±1% accurate, 12-bit ADC for current, VIN/VOUT readback

        Charge-pumped gate drive for multiple external N-channel FETs

        High gate drive voltage to ensure lowest RDSON

        Foldback for tighter FET SOA protection

        Automatic retry or latch-off on current fault

        Programmable current limit timer for SOA

        Programmable, multifunction GPOs

        Power-good status output

        Analog UV and OV protection

        ENABLE pin (ADM1275-3 only)

        Peak detect registers for current and voltage

        PMBus fast mode compliant interface

        16-lead QSOP and 20-lead QSOP and LFCSP

        ADM1275應用:

        Power monitoring and control/power budgeting

        Central office equipment

        Telecommunication and data communication equipment

        PCs/servers

        圖1.ADM1275-1功能方框圖

        圖2.ADM1275-2功能方框圖

        圖3.ADM1275-3功能方框圖

        評估板EVAL-ADM127xEBZ

        The EVAL-ADM127xEBZ is a compact full feature evaluation board for the ADM1275-1ACPZ, ADM1275-3ACPZ, and ADM1276-3ACPZ devices. The elaborated layout gives users a clear visual of all the peripheral components and the hot-swap power path. The layout also maximizes the board’s ability to dissipate heat for some of the key components on the power path, allowing the evaluation of very high current hot-swap setups.

        Three sense-resistor slots and six multipackage FET slots give users great flexibility and allow them to simulate a wide range of application setups.

        Multiple test points allow easy access to all critical points/pins. Six LEDs give users direct visual indication on variations in the board status, such as supply input, output, IC power good output, latch output, and GPO outputs. Six ADT75 digital temperature sensors on the back of the board allow users to obtain the board’s thermal data through an I2C bus in real time.

        The kit supports I2C communication, allowing users to communicate with the ADM1275/ADM1276 and the ADT75. The evaluation kit also supports cascade setup so multiple evaluation boards can be connected together and share the same I2C bus.

        The boards are fully compatible with the ADM1275/ADM1276 evaluation software tool, which can be downloaded at: www.analog.com/hotswap_powermonitor.

        Note that users may need the USB-to-I2C dongle, USB-SMBUS-CABLEZ, to use the evaluation software tools.
        The standard evaluation kit is prepopulated and tested with a 12 V, 60 A hot-swap design capable of working with a 4.7 mF output capacitor.

        Complete specifications for the ADM1275 and the ADM1276 are available in the ADM1275 and the ADM1276 data sheets available from Analog Devices and should be consulted in conjunction with this user guide when using the evaluation boards.

        評估板EVAL-ADM127xEBZ主要特性:

        Full functions support evaluation kit for the ADM1275 and the ADM1276

        Supports LFCSP device package

        Populated and tested with 12 V, 60 A, 4.7 mF design

        Capable of evaluating high current designs for over 100 A

        Special NMOSFET footprint suits different packages

        Supports up to 3 sense resistors in parallel

        Supports up to 6 FETs in parallel

        LED indicated status outputs

        Wild input voltage range of up to 20 V

        Allows separate VCC and VIN for low voltage sensing

        6 on-board ADT75 accurate temperature sensors

        Supports cascade setup for multiple boards

        Toggle and push-button switch for easy input control

        PMBus communication support

        圖4.評估板EVAL-ADM127xEBZ外形圖

        圖5.評估板EVAL-ADM127xEBZ電路圖(1)

        圖6.評估板EVAL-ADM127xEBZ電路圖(2)

        圖7.評估板EVAL-ADM127xEBZ PCB布局圖
        評估板EVAL-ADM127xEBZ材料清單(BOM):

        詳情請見:
        http://www.analog.com/static/imported-files/data_sheets/ADM1275.pdf

        http://www.analog.com/static/imported-files/user_guides/UG-263.pdf


        關鍵詞: 電源管理 熱插拔 ADC

        評論


        相關推薦

        技術專區

        關閉
        主站蜘蛛池模板: 日喀则市| 工布江达县| 潼南县| 巴南区| 鄂伦春自治旗| 石家庄市| 乃东县| 安平县| 台前县| 云南省| 肃北| 溧阳市| 青田县| 渑池县| 南城县| 龙口市| 旌德县| 德清县| 本溪市| 满城县| 眉山市| 舞阳县| 绍兴市| 吉林省| 永善县| 南昌县| 彩票| 潜江市| 富裕县| 田东县| 本溪| 余江县| 正安县| 曲沃县| 武夷山市| 三亚市| 丹寨县| 白银市| 广宗县| 崇明县| 北宁市|