參數(shù)資料
型號: L6599D
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
封裝: LEAD FREE, SOP-16
文件頁數(shù): 20/36頁
文件大?。?/td> 636K
代理商: L6599D
L6599
Application information
27/36
The timing diagram of Figure 32 shows this operation.
Note that if during TSTOP the supply voltage of the L6599 (Vcc) falls below the UVLO
threshold the IC keeps memory of the event and will not restart immediately after VCC
exceeds the start-up threshold if V(DELAY) is still higher than 0.3 V. Also the PFC_STOP pin
will stay low as long as V(DELAY) is greater than 0.3 V. Note also that in case there is an
overload lasting less than TSH, the value of TSH for the next overload will be lower if they are
close to one another.
7.5
Latched shutdown
The device is equipped with a comparator having the non-inverting input externally available
at pin 8 (DIS) and with the inverting input internally referenced to 1.85 ‘V. As the voltage on
the pin exceeds the internal threshold, the IC is immediately shut down and its consumption
reduced at a low value. The information is latched and it is necessary to let the voltage on
the Vcc pin go below the UVLO threshold to reset the latch and restart the IC.
This function is useful to implement a latched overtemperature protection very easily by
biasing the pin with a divider from an external reference voltage, where the upper resistor is
an NTC physically located close to a heating element like the MOSFET, or the secondary
diode or the transformer.
An OVP can be implemented as well, e.g. by sensing the output voltage and transferring an
overvoltage condition via an optocoupler.
7.6
Line sensing function
This function basically stops the IC as the input voltage to the converter falls below the
specified range and lets it restart as the voltage goes back within the range. The sensed
voltage can be either the rectified and filtered mains voltage, in which case the function will
act as a brownout protection, or, in systems with a PFC pre-regulator front-end, the output
voltage of the PFC stage, in which case the function will serve as power-on and power-off
sequencing.
L6599 shutdown upon input undervoltage is accomplished by means of an internal
comparator, as shown in the block diagram of Figure 33, whose non-inverting input is
available at pin 7 (LINE). The comparator is internally referenced to 1.25 V and disables the
IC if the voltage applied on the LINE pin is below the internal reference. Under these
conditions the soft-start is discharged, the PFC_STOP pin is open and the consumption of
the IC is reduced. PWM operation is re-enabled as the voltage on the pin is above the
reference. The comparator is provided with current hysteresis instead of a more usual
voltage hysteresis: an internal 1 A current sink is ON as long as the voltage on the LINE pin
is below the reference and is OFF if the voltage is above the reference.
This approach provides an additional degree of freedom: it is possible to set the ON
threshold and the OFF threshold separately by properly choosing the resistors of the
external divider (see below). With voltage hysteresis, instead, fixing one threshold
automatically fixes the other one depending on the built-in hysteresis of the comparator.
相關(guān)PDF資料
PDF描述
L6599N 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDIP16
L6599TR 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
L6610D 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO24
L6610N 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDIP24
L6611DTRT POWER SUPPLY SUPPORT CKT, PDSO20
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L6599DTR 功能描述:軟開關(guān) PWM 控制器 Hi Vltg resonant Controller RoHS:否 制造商:Fairchild Semiconductor 輸出端數(shù)量: 輸出電流: 開關(guān)頻率: 工作電源電壓:30 V 電源電流: 最大工作溫度:+ 105 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel
L6599N 功能描述:軟開關(guān) PWM 控制器 Hi Vltg resonant Controller RoHS:否 制造商:Fairchild Semiconductor 輸出端數(shù)量: 輸出電流: 開關(guān)頻率: 工作電源電壓:30 V 電源電流: 最大工作溫度:+ 105 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel
L6599NR 功能描述:電壓模式 PWM 控制器 HV resonant CNTRL RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
L6599TR 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:High-voltage resonant controller
L65B 制造商:Electro-Mech 功能描述: