• 參數(shù)資料
    型號(hào): MAX1883EUP
    廠商: MAXIM INTEGRATED PRODUCTS INC
    元件分類: 穩(wěn)壓器
    英文描述: Replaced by TMS320C6211B : Fixed-Point Digital Signal Processor 256-BGA 0 to 0
    中文描述: 2.05 A SWITCHING REGULATOR, 1250 kHz SWITCHING FREQ-MAX, PDSO20
    封裝: 4.40 MM, 1.10 MM HEIGHT, MO-153AC, TSSOP-20
    文件頁(yè)數(shù): 22/38頁(yè)
    文件大?。?/td> 1051K
    代理商: MAX1883EUP
    M
    Quad-Output TFT LCD DC-DC
    Converters with Buffer
    22
    ______________________________________________________________________________________
    Negative Charge Pump
    During the first half-cycle, the P-channel MOSFET turns
    on, and flying capacitor C
    X(NEG)
    charges to V
    SUPN
    minus a diode drop (Figure 4). During the second half-
    cycle, the P-channel MOSFET turns off, and the N-
    channel MOSFET turns on, level shifting C
    X(NEG)
    . This
    connects C
    X(NEG)
    in parallel with reservoir capacitor
    C
    OUT(NEG)
    . If the voltage across C
    OUT(NEG)
    minus a
    diode drop is greater than the voltage across C
    X(NEG)
    ,
    charge flows from C
    OUT(NEG)
    to C
    X(NEG)
    until the diode
    (D5) turns off. The amount of charge transferred to the
    output is controlled by the variable N-channel on-resis-
    tance.
    Low-Dropout Linear Regulator (MAX1778/
    MAX1881/MAX1883/MAX1884 Only)
    The MAX1778/MAX1881/MAX1883/MAX1884 contain a
    low-dropout linear regulator (Figure 5) that uses an
    internal PNP pass transistor (Q
    P
    ) to supply loads up to
    40mA. As illustrated in Figure 5, the 1.25V reference is
    connected to the error amplifier, which compares this
    reference with the feedback voltage and amplifies the
    difference. If the feedback voltage is higher than the
    reference voltage, the controller lowers the base cur-
    rent of Q
    P
    , which reduces the amount of current to the
    output. If the feedback voltage is too low, the device
    increases the pass transistor base current, which
    allows more current to pass to the output and increases
    the output voltage. However, the linear regulator also
    includes an output current limit to protect the internal
    pass transistor against short circuits.
    The low-dropout linear regulator monitors and controls
    the pass transistor
    s base current, limiting the output
    current to 130mA (typ). In conjunction with the thermal
    overload protection, this current limit protects the out-
    put, allowing it to be shorted to ground for an indefinite
    period of time without damaging the part.
    VCOM Buffer
    The MAX1778/MAX1880
    MAX1885 include a VCOM
    buffer, which uses an operational transconductance
    amplifier (OTA) to provide a current output that is ideal
    for driving capacitive loads, such as the backplane of a
    TFT LCD panel. The unity-gain bandwidth of this cur-
    rent-output buffer is:
    GBW = gm/C
    OUT
    where gm is the amplifier
    s transconductance. The
    bandwidth is inversely proportional to the output
    capacitor, so large capacitive loads improve stability;
    however, lower bandwidth decreases the buffer
    s tran-
    sient response time. To improve the transient response
    SUPL
    C
    SUPL
    V
    4.5V TO 15V
    C
    LDOOUT
    LDOOUT
    V
    LDOOUT
    1.25V TO (V
    SUPL
    - 0.3V)
    FBL
    V
    REF
    1.25V
    ERROR
    AMPLIFIER
    GND
    R8
    R7
    Q
    P
    CURRENT
    LIMIT
    THERMAL
    SENSOR
    V
    LDOOUT
    =
    (
    1 + R7
    )
    V
    REF
    V
    REF
    = 1.25V
    R8
    MAX1778
    MAX1881
    MAX1883
    MAX1884
    Figure 5. Low-Dropout Linear Regulator Block Diagram
    相關(guān)PDF資料
    PDF描述
    MAX1884EUP Fixed-Point Digital Signal Processor 256-BGA
    MAX1885EUP Fixed-Point Digital Signal Processor 256-BGA
    MAX1778EUG Quad-Output TFT LCD DC-DC Converters with Buffer
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    MAX1881EUG Quad-Output TFT LCD DC-DC Converters with Buffer
    相關(guān)代理商/技術(shù)參數(shù)
    參數(shù)描述
    MAX1883EUP-T 功能描述:LCD 驅(qū)動(dòng)器 Quad-Output TFT LCD DC-DC Converter with Buffer RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
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    MAX1885EUP 功能描述:LCD 驅(qū)動(dòng)器 Quad-Output TFT LCD DC-DC Converter with Buffer RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube
    MAX1885EUP-T 功能描述:LCD 驅(qū)動(dòng)器 Quad-Output TFT LCD DC-DC Converter with Buffer RoHS:否 制造商:Maxim Integrated 數(shù)位數(shù)量:4.5 片段數(shù)量:30 最大時(shí)鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube