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    參數(shù)資料
    型號(hào): TC1303B-FA0EMFTR
    廠商: Microchip Technology Inc.
    英文描述: 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output
    中文描述: 500毫安同步降壓穩(wěn)壓器,300 mA的LDO具有電源就緒輸出
    文件頁數(shù): 16/30頁
    文件大?。?/td> 441K
    代理商: TC1303B-FA0EMFTR
    TC1303B
    DS21949A-page 16
    2005 Microchip Technology Inc.
    4.0
    DETAILED DESCRIPTION
    4.1
    Device Overview
    The TC1303B combines a 500 mA synchronous buck
    regulator with a 300 mA LDO and a power-good output.
    This unique combination provides a tiny, low-cost
    solution for applications that require two or more
    voltage rails. The buck regulator can deliver high-
    output current over a wide range of input-to-output
    voltage ratios while maintaining high efficiency. This is
    typically used for the lower-voltage, high-current
    processor core. The LDO is a minimal parts-count
    solution,
    (single-output
    regulated voltage for an auxiliary rail. The typical LDO
    dropout voltage (137 mV @ 200 mA) allows the use of
    very low input-to-output LDO differential voltages,
    minimizing the power loss internal to the LDO pass
    transistor. A power-good output is provided, indicating
    that the LDO output is in regulation (TC1303B).
    Additional features include independent shutdown
    inputs, UVLO, overcurrent and overtemperature
    shutdown.
    capacitor),
    providing
    a
    4.2
    Synchronous Buck Regulator
    The synchronous buck regulator is capable of supply-
    ing a 500 mA continuous output current over a wide
    range of input and output voltages. The output voltage
    range is from 0.8V (min) to 4.5V (max). The regulator
    operates in three different modes and automatically
    selects the most efficient mode of operation. During
    heavy load conditions, the TC1303B buck converter
    operates at a high, fixed frequency (2.0 MHz) using
    current mode control. This minimizes output ripple and
    noise (less than 8 mV peak-to-peak ripple) while main-
    taining high efficiency (typically > 90%). For standby or
    light load applications, the buck regulator will automat-
    ically switch to a power-saving Pulse Frequency
    Modulation (PFM) mode. This minimizes the quiescent
    current draw on the battery, while keeping the buck
    output voltage in regulation. The typical buck PFM
    mode current is 38 μA. The buck regulator is capable of
    operating at 100% duty cycle, minimizing the voltage
    drop from input to output for wide input battery-
    powered applications. For fixed-output voltage applica-
    tions, the feedback divider and control loop compensa-
    tion components are integrated, eliminating the need
    for external components. The buck regulator output is
    protected against overcurrent, short circuit and over-
    temperature. While shut down, the synchronous buck
    N-channel and P-channel switches are off, so the L
    X
    pin is in a high-impedance state (this allows for
    connecting a source on the output of the buck regulator
    as long as its voltage does not exceed the input
    voltage).
    4.2.1
    FIXED FREQUENCY PWM MODE
    While operating in Pulse Width Modulation (PWM)
    mode, the TC1303B buck regulator switches at a fixed
    2.0 MHz frequency. The PWM mode is suited for higher
    load current operation, maintaining low output noise
    and high conversion efficiency. PFM to PWM mode
    transition is initiated for any of the following conditions.
    Continuous inductor current is sensed
    Inductor peak current exceeds 100 mA
    The buck regulator output voltage has dropped
    out of regulation (step load has occurred)
    The typical PFM-to-PWM threshold is 80 mA.
    4.2.2
    PFM MODE
    PFM mode is entered when the output load on the buck
    regulator is very light. Once detected, the converter
    enters the PFM mode automatically and begins to skip
    pulses to minimize unnecessary quiescent current
    draw by reducing the number of switching cycles per
    second. The typical quiescent current for the switching
    regulator is less than 35 μA. The transition from PWM
    to PFM mode occurs when discontinuous inductor
    current is sensed, or the peak inductor current is less
    than 60 mA (typ.). The typical PWM to PFM mode
    threshold is 30 mA. For low input-to-output differential
    voltages, the PWM to PFM mode threshold can be low
    due to the lack of ripple current. It is recommended that
    V
    IN1
    be one volt greater than V
    OUT1
    for PWM to PFM
    transitions.
    4.3
    Low Drop Out Regulator (LDO)
    The LDO output is a 300 mA low-dropout linear regula-
    tor that provides a regulated output voltage with a
    single 1 μF external capacitor. The output voltage is
    available in fixed options only, ranging from 1.5V to
    3.3V. The LDO is stable using ceramic output capaci-
    tors that inherently provide lower output noise and
    reduce the size and cost of the regulator solution. The
    quiescent current consumed by the LDO output is
    typically less than 20 μA, with a typical dropout voltage
    of 137 mV at 200 mA. The LDO output is protected
    against overcurrent and overtemperature.
    相關(guān)PDF資料
    PDF描述
    TC1303B-FA0EUN 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output
    TC1303B-FA0EUNTR 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output
    TC1303B-FA1EMF 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output
    TC1303B-FA1EMFTR 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output
    TC1303B-FA1EUN 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output
    相關(guān)代理商/技術(shù)參數(shù)
    參數(shù)描述
    TC1303B-IA0EMF 功能描述:低壓差穩(wěn)壓器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
    TC1303B-IA0EMFTR 功能描述:低壓差穩(wěn)壓器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
    TC1303B-IA0EUN 功能描述:低壓差穩(wěn)壓器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
    TC1303B-IA0EUNTR 功能描述:低壓差穩(wěn)壓器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
    TC1303B-PA0EMF 功能描述:低壓差穩(wěn)壓器 - LDO PWM/LDO combo w/PG RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20