• 參數(shù)資料
    型號(hào): HSMS-282C
    英文描述: Surface Mount RF Schottky Barrier Diodes(表貼型射頻肖特基勢壘二極管)
    中文描述: 表面貼裝射頻肖特基二極管(表貼型射頻肖特基勢壘二極管)
    文件頁數(shù): 9/12頁
    文件大?。?/td> 141K
    代理商: HSMS-282C
    9
    Sampling Applications
    The six lead HSMS-282P can be
    used in a sampling circuit, as
    shown in Figure 25. As was the
    case with the six lead HSMS-282R
    in the mixer, the open bridge
    quad is closed with traces on the
    circuit board. The quad was not
    closed internally so that it could
    be used in other applications,
    such as illustrated in Figure 17.
    HSMS-282P
    sampling
    pulse
    sample
    point
    sampling circuit
    Figure 25. Sampling Circuit.
    Thermal Considerations
    The obvious advantage of the
    SOT-323 and SOT-363 over the
    SOT-23 and SOT-142 is combina-
    tion of smaller size and extra
    leads. However, the copper
    leadframe in the SOT-3x3 has a
    thermal conductivity four times
    higher than the Alloy 42
    leadframe of the SOT-23 and
    SOT-143, which enables the
    smaller packages to dissipate
    more power.
    The maximum junction tempera-
    ture for these three families of
    Schottky diodes is 150
    °
    C under
    all operating conditions. The
    following equation applies to the
    thermal analysis of diodes:
    Tj = (V
    f
    I
    f
    + P
    RF
    )
    θ
    jc
    + T
    a
    (1)
    where
    T
    j
    = junction temperature
    T
    a
    = diode case temperature
    θ
    jc
    = thermal resistance
    V
    f
    I
    f
    = DC power dissipated
    P
    RF
    = RF power dissipated
    Note that
    θ
    jc
    , the thermal resis-
    tance from diode junction to the
    foot of the leads, is the sum of
    two component resistances,
    θ
    jc
    =
    θ
    pkg
    +
    θ
    chip
    (2)
    Package thermal resistance for
    the SOT-3x3 package is approxi-
    mately 100
    °
    C/W, and the chip
    thermal resistance for the
    HSMS-282x family of diodes is
    approximately 40
    °
    C/W. The
    designer will have to add in the
    thermal resistance from diode
    case to ambient—a poor choice
    of circuit board material or heat
    sink design can make this number
    very high.
    Equation (1) would be straightfor-
    ward to solve but for the fact that
    diode forward voltage is a func-
    tion of temperature as well as
    forward current. The equation for
    V
    f
    is:
    11600 (V
    f
    – I
    f
    R
    s
    )
    = I
    I
    S
    e – 1
    where n = ideality factor
    T = temperature in
    °
    K
    R
    s
    = diode series resistance
    and I
    S
    (diode saturation current)
    is given by
    2 1 1
    n – 4060
    T – 298
    )
    I
    = I
    (
    T
    )
    e
    298 (4)
    Equation (4) is substituted into
    equation (3)
    ,
    and equations (1)
    and (3) are solved simultaneously
    to obtain the value of junction
    temperature for given values of
    diode case temperature, DC
    power dissipation and RF power
    dissipation.
    Diode Burnout
    Any Schottky junction, be it an RF
    diode or the gate of a MESFET, is
    relatively delicate and can be
    burned out with excessive RF
    power. Many crystal video
    receivers used in RFID (tag)
    applications find themselves in
    poorly controlled environments
    where high power sources may be
    present. Examples are the areas
    around airport and FAA radars,
    nearby ham radio operators, the
    vicinity of a broadcast band
    transmitter, etc. In such
    environments, the Schottky
    diodes of the receiver can be
    protected by a device known as a
    limiter diode.
    [5]
    Formerly
    available only in radar warning
    receivers and other high cost
    electronic warfare applications,
    these diodes have been adapted to
    commercial and consumer
    circuits.
    Agilent offers a complete line of
    surface mountable PIN limiter
    diodes. Most notably, our HSMP-
    4820 (SOT-23) can act as a very
    fast (nanosecond) power-sensitive
    switch when placed between the
    antenna and the Schottky diode,
    shorting out the RF circuit
    temporarily and reflecting the
    excessive RF energy back out the
    antenna.
    [5]
    Agilent Application Note 1050, “Low
    Cost, Surface Mount Power Limiters.”
    相關(guān)PDF資料
    PDF描述
    HSMS-282E Surface Mount RF Schottky Barrier Diodes(表貼型射頻肖特基勢壘二極管)
    HSMS-282F Surface Mount RF Schottky Barrier Diodes(表貼型射頻肖特基勢壘二極管)
    HSMS-282K Surface Mount RF Schottky Barrier Diodes(表貼型射頻肖特基勢壘二極管)
    HSMS-282L Surface Mount RF Schottky Barrier Diodes(表貼型射頻肖特基勢壘二極管)
    HSMS-282M Surface Mount RF Schottky Barrier Diodes(表貼型射頻肖特基勢壘二極管)
    相關(guān)代理商/技術(shù)參數(shù)
    參數(shù)描述
    HSMS-282C-BLK 制造商:Avago Technologies 功能描述:Rectifier Diode, Doubler, Schottky, 15 Volt, SOT-323
    HSMS-282C-BLKG 功能描述:肖特基二極管與整流器 15 VBR 1 pF RoHS:否 制造商:Skyworks Solutions, Inc. 產(chǎn)品:Schottky Diodes 峰值反向電壓:2 V 正向連續(xù)電流:50 mA 最大浪涌電流: 配置:Crossover Quad 恢復(fù)時(shí)間: 正向電壓下降:370 mV 最大反向漏泄電流: 最大功率耗散:75 mW 工作溫度范圍:- 65 C to + 150 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOT-143 封裝:Reel
    HSMS-282C-BLKG 制造商:Avago Technologies 功能描述:Schottky Rectifier
    HSMS-282C-G 制造商:Avago Technologies 功能描述:HSMS-282C dual series Schottky diode
    HSMS-282C-TR1 制造商:Agilent Technologies 功能描述:Rectifier Diode, Doubler, Schottky, 15 Volt, SOT-323 制造商:Hewlett Packard Co 功能描述:Rectifier Diode, Doubler, Schottky, 15 Volt, SOT-323