參數(shù)資料
型號(hào): L6563H
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: POWER FACTOR CONTROLLER, PDSO16
封裝: ROHS COMPLIANT, SOP-16
文件頁數(shù): 25/48頁
文件大?。?/td> 1634K
代理商: L6563H
L6563H
Application information
Doc ID 16047 Rev 2
31/48
Figure 44.
Tracking output voltage vs Input voltage characteristic with TBO
6.6
Inductor saturation detection
Boost inductor's hard saturation may be a fatal event for a PFC pre-regulator: the current up-
slope becomes so large (50-100 times steeper, see Figure 45) that during the current sense
propagation delay the current may reach abnormally high values. The voltage drop caused
by this abnormal current on the sense resistor reduces the gate-to-source voltage, so that
the MOSFET may work in the active region and dissipate a huge amount of power, which
leads to a catastrophic failure after few switching cycles.
However, in some applications such as ac-dc adapters, where the PFC pre-regulator is
turned off at light load for energy saving reasons, even a well-designed boost inductor may
occasionally slightly saturate when the PFC stage is restarted because of a larger load
demand. This happens when the restart occurs at an unfavorable line voltage phase, i.e.
when the output voltage is significantly below the rectified peak voltage. As a result, in the
boost inductor the inrush current coming from the bridge rectifier adds up to the switched
current and, furthermore, there is little or no voltage available for demagnetization.
To cope with a saturated inductor, the L6563H is provided with a second comparator on the
current sense pin (CS, pin 4) that stops the IC if the voltage, normally limited within 1.1 V,
exceeds 1.7 V. After that, the IC attempts to restart by the internal starter circuitry; the
starter repetition time is twice the nominal value to guarantee lower stress for the inductor
and boost diode. Hence, the system safety is considerably increased.
Figure 45.
Effect of boost inductor saturation on the MOSFET current and detection method
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L6563S 功能描述:功率因數(shù)校正 IC Transition Mode PFC 5mA 90uA 1.5% Ref RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel
L6563STR 功能描述:功率因數(shù)校正 IC Transition Mode PFC 5mA 90uA 1.5% Ref RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel
L6563TR 功能描述:功率因數(shù)校正 IC POWER SUPPLY RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel
L6564 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:10 pin transition-mode PFC controller