參數(shù)資料
型號(hào): L6566ATR
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: 0.8 A POWER FACTOR CONTROLLER WITH POST REGULATOR, 300 kHz SWITCHING FREQ-MAX, PDSO16
封裝: LEAD FREE, SOP-16
文件頁數(shù): 32/51頁
文件大?。?/td> 646K
代理商: L6566ATR
Application information
L6566A
38/51
5.12
Brownout protection
Brownout protection is basically a not-latched device shutdown function activated when a
condition of mains undervoltage is detected. There are several reasons why it may be
desirable to shut down a converter during a brownout condition, which occurs when the
mains voltage falls below the minimum specification of normal operation.
Firstly, a brownout condition may cause overheating of the PFC front-end due to an excess
of RMS current. Secondly, brownout can also cause the PFC pre-regulator to work open
loop. This could be dangerous to the PFC itself and the downstream converter, should the
input voltage return abruptly to its rated value, given the slow response of PFC to transient
events. Finally, spurious restarts may occur during converter power down, hence causing
the output voltage not to decay to zero monotonically.
L6566A shutdown upon brownout is accomplished by means of an internal comparator, as
shown in the block diagram of Figure 25, which shows the basic circuit usage. The inverting
input of the comparator, available on the AC_OK pin (16), is supposed to sense a voltage
proportional to either the RMS or the peak mains voltage; the non-inverting input is
internally referenced to 0.485 V with 35 mV hysteresis. If the voltage applied on the AC_OK
pin before the device starts operating does not exceed 0.485 V or if it falls below 0.45 V
while the device is running, The AC_OK signal goes high, the pin Vcc_PFC is open and the
device shuts down, with the soft-start capacitor discharged and the gate-drive output low.
Additionally, in case the device has been latched off by some protection function (in which
case Vcc is oscillating between VccON and VccON - 0.5 V) the AC_OK voltage falling below
0.45 V will clear the latch. This feature can be used to allow a quicker restart as the input
source is removed.
Figure 25.
Brownout protection: internal block diagram and timing diagram
-
+
L6566A
AC_FAIL
AC_OK
Vcc
16
5
0.485V
0.45V
15 A
RH
RL
Sensed
voltage
Vcc
(pin 5)
GD
(pin 4)
Vout
VAC_OK
(pin 16)
0.45V
IHYS
15 A
t
Vcc_PFC
(pin 6)
AC_FAIL
Sensed voltage
VsenON
VsenOFF
0.485V
相關(guān)PDF資料
PDF描述
L6605D SPECIALTY CONSUMER CIRCUIT, PDSO20
L6605 SPECIALTY CONSUMER CIRCUIT, PDIP18
L6660 SPECIALTY CONSUMER CIRCUIT, PDSO24
L6920DBTR 0.9 A SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO8
L6920DB 0.9 A SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L6566B 功能描述:開關(guān)變換器、穩(wěn)壓器與控制器 Multi Mode PWM Controller RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關(guān)頻率:1 MHz 工作溫度范圍: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel
L6566B_08 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Multi-mode controller for SMPS
L6566BH 功能描述:電流型 PWM 控制器 Multimode Controller SMPS 800V <3mA RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
L6566BHTR 功能描述:電流型 PWM 控制器 MULTIMODE CONTROLLER SMPS 8V 3 mA RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
L6566BTR 功能描述:電流型 PWM 控制器 MultiMode Controller for SMPS RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14