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HP Power Supply Fan Controller DATA SHEET

 HPFANG+/-
  • GENERAL DESCRIPTION         

    HPFANG+/- is designed for HP related application.   The target application is for the Fan Control Section of HP PC Power Supply.   It might infringe HP patent if the application is not relate to HP related business.

    HPFANG+/- is designed to achieve high performance and high efficiency with low cost BOM.   With HPFANG+/-, the application   ma reduce   one   FAN.It   combines   PC motherboard temperature information and the temperature information   o PC   powe supply.   The   temperature information of PC power supply is an analog signal called TFB, which can be generated by a simple Thermistor.   The temperature information of PC motherboard usually is presented by the duty cycle of the signal called FANCMD.

    TEAO and TFB are output and inverting input of the OP.The non-inverting input of TEAO OP is connected to internal 2.5V reference A simple inverting gain configuration with a thermistor in series of a current limit resistor Rs can program the TEAO to search for the duty cycle of FANPWMOUT which corresponds with the fan speed at the temperature. When TEAO is greater than 3.5V, the FANPWMOUT duty cycle is 100%.   When TEAO is ~ 2.5V, the  FANPWMOUT  duty cycle  is ~50%.    When TEAO is below 1.5V, the FANPWMOUT duty cycle is ~ 1.5%.

    Usually, 50% duty cycle of FANPWMOUT corresponds to 50% Power Supply load at room temperature, and 5% duty cycle of FANPWMOUT corresponds to 20% Power Supply load at room temperature.To have FANPWMOUT ~ 50%, TEAO is ~2.5V.

    HPFANG+/-  is  inverting  the  complimentary  duty  cycle  of FANCMD  to  FANPWMOUT.  FANCMD  duty cycle  is  ~ FANPWMOUT duty cycle.

    HPFANG+/-  selects  the  highest  voltage  among  TEAO,CAVERAGE to compare with oscillator ramp, which is 1.5V to 3.5V.

    HPFANG+/-   desig tool   i available.   Pleas contact

    Champion Sales.

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    Features

    P Combine Mother Board Temperature Signals with Power

       Supply Temperature Signals
    P Low BOM and It may reduce one Fan
    P Precision OP (TEAO) uses TFB to sense the thermistor information at power supply
    P Precision 25KHz Ramp generator: Peak ~ 3.5V (Duty  100%) and Valley ~1.5V (Duty ~1.5%)
    P Precision  25KHz  Ramp  generator  compares  TEAO, Caverage,  and  Fault  to  determine  the  duty       

      cycle  of FANPWMOUT
    P It does not require negative voltage

     P Accept  Pulse  PWMing  signal  FANCMD  (prefer  it  is below 100Khz) from Mother Board

    P .Precision Duty to Duty Converter or called a Pulse to

        Pulse Converter or called PWMing to PWMing Converter
    P The amplitude of Input pulse (FANCMD), peak to peak can be from 0V - 5V to 0V - 2V
    P Minimum VCC > 8V Power Supply

    P Preferred VCC~ 12V

    P Precision (1% variation) 5V Reference Voltage
    P Precision Internally Generated 25KHz +/-10% Switching

       Frequency
    P FANPWMOUT 1.5% to 100% Output Duty Cycle
    P Thermal Shut Down can be done by sensing TFB or

       TEAO
    P Low Operating Current, Ivcc ~ 0.5mA

    P 8 pin package

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     Packages

  • DIP-8 / SOP-8

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Datasheet PDF file

HPFANG  PDF

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