參數(shù)資料
型號(hào): L6566A
廠商: 意法半導(dǎo)體
元件分類: 基準(zhǔn)電壓源/電流源
英文描述: Multi-mode controller for SMPS with PFC front-end
中文描述: 多模式開(kāi)關(guān)電源控制器,PFC前端
文件頁(yè)數(shù): 25/51頁(yè)
文件大?。?/td> 410K
代理商: L6566A
L6566A
Application information
25/51
Figure 12. Addition of an offset to the current sense lowers the burst-mode operation
threshold
5.4
Adaptive UVLO
A major problem when optimizing a converter for minimum no-load consumption is that the
voltage generated by the auxiliary winding under these conditions falls considerably as
compared even to a few mA load. This very often causes the supply voltage Vcc of the
control IC to drop and go below the UVLO threshold so that the operation becomes
intermittent, which is undesired. Furthermore, this must be traded off against the need of
generating a voltage not exceeding the maximum allowed by the control IC at full load.
To help the designer overcome this problem, the device, besides reducing its own
consumption during burst-mode operation, also features a proprietary adaptive UVLO
function. It consists of shifting the UVLO threshold downwards at light load, namely when
the voltage at pin COMP falls below a threshold V
COMPO
internally fixed (see "PFC
Interface"), so as to have more headroom. To prevent any malfunction during transients from
minimum to maximum load the normal (higher) UVLO threshold is re-established when the
voltage at pin COMP exceeds V
COMPL
(see "
Chapter 5.8: PFC interface on page 31
") and
Vcc has exceeded the normal UVLO threshold (see
Figure 13
). The normal UVLO threshold
ensures that at full load the MOSFET will be driven with a proper gate-to-source voltage.
Rs
L6566A
R
Vref
Rc
10
4
7
3
Vcs
o
= Vref
R
R + Rc
Figure 13. Adaptive UVLO block
V
COMPL
V
COMPO
VCOMP
(pin 9)
(Vcc
Q
OFF1
Vcc
OFF2
t
t
t
t
Vcc_PFC
(pin 6)
Tdelay
(*) Vcc
OFF2
< Vcc
OFF1
is selected when Q is high
+
-
UVLO
Vcc
OFF1
Vcc
L6566A
COMP
R
S Q
+
-
+
-
Vcc
OFF2
(*)
SW
5
9
V
COMPL
V
COMPO
Vcc_PFC
logic
Vcc_PFC
6
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L6566A_08 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:Multi-mode controller for SMPS with PFC front-end
L6566ATR 功能描述:開(kāi)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(kāi)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 功能描述:開(kāi)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(kāi)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(kāi)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