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參數(shù)資料
| 型號： | FSCM0565RCYDTU_NL |
| 廠商： | FAIRCHILD SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 20 A SWITCHING REGULATOR, 72 kHz SWITCHING FREQ-MAX, PZFM6 |
| 封裝： | TO-220, 6PIN |
| 文件頁數(shù)： | 3/23頁 |
| 文件大?。?/td> | 604K |
| 代理商： | FSCM0565RCYDTU_NL |
FSCM0565R
11
current spike through the SenseFET, caused by primary-side
capacitance and secondary-side rectifier reverse recovery.
Excessive voltage across the Rsense resistor can lead to
incorrect feedback operation in the current mode PWM
control. To counter this effect, the FSCM0565R employs a
leading edge blanking (LEB) circuit. This circuit inhibits the
PWM comparator for a short time (TLEB) after the SenseFET
is turned on.
3. Protection Circuit: The FSCM0565R has several self
protective functions such as over load protection (OLP), over
voltage protection (OVP) and thermal shutdown (TSD).
Because these protection circuits are fully integrated into the
IC without external components, the reliability can be
improved without increasing cost. Once the fault condition
occurs, switching is terminated and the SenseFET remains
off. This causes Vcc to fall. When Vcc reaches the UVLO
stop
voltage
of
8V,
the
current
consumed
by
the
FSCM0565R decreases to the startup current (typically
25uA) and the current supplied from the DC link charges the
external capacitor (Ca) that is connected to the Vcc pin.
When Vcc reaches the start voltage of 12V, the FSCM0565R
resumes its normal operation. In this manner, the auto-restart
can alternately enable and disable the switching of the power
SenseFET until the fault condition is eliminated (see Figure
19).
Figure 19. Auto Restart Operation
3.1 Over Load Protection (OLP): Overload is defined as
the load current exceeding a pre-set level due to an
unexpected event. In this situation, the protection circuit
should be activated to protect the SMPS. However, even
when the SMPS is in the normal operation, the over load
protection circuit can be activated during the load transition.
To avoid this undesired operation, the over load protection
circuit is designed to be activated after a specified time to
determine whether it is a transient situation or an overload
situation. Because of the pulse-by-pulse current limit
capability, the maximum peak current through the SenseFET
is limited, and therefore the maximum input power is
restricted with a given input voltage. If the output consumes
beyond this maximum power, the output voltage (Vo)
decreases below the set voltage. This reduces the current
through the opto-coupler LED, which also reduces the opto-
coupler transistor current, thus increasing the feedback
voltage (Vfb). If Vfb exceeds 2.5V, D1 is blocked and the
5.3uA current source (Idelay) starts to charge CB slowly up to
Vcc. In this condition, Vfb continues increasing until it
reaches 6V, when the switching operation is terminated as
shown in Figure 20. The delay time for shutdown is the time
required to charge CB from 2.5V to 6.0V with 5.3uA (Idelay).
In general, a 10 ~ 50 ms delay time is typical for most
applications.
Figure 20. Over Load Protection
3.2 Over Voltage Protection (OVP): If the secondary side
feedback circuit were to malfunction or a solder defect
caused an open in the feedback path, the current through the
opto-coupler transistor becomes almost zero. Then, Vfb
climbs up in a similar manner to the over load situation,
forcing the preset maximum current to be supplied to the
SMPS until the over load protection is activated. Because
more energy than required is provided to the output, the
output voltage may exceed the rated voltage before the over
load protection is activated, resulting in the breakdown of the
devices in the secondary side. To prevent this situation, an
over voltage protection (OVP) circuit is employed. In
general, Vcc is proportional to the output voltage and the
FSCM0565R uses Vcc instead of directly monitoring the
output voltage. If VCC exceeds 19V, an OVP circuit is
activated resulting in the termination of the switching
operation. To avoid undesired activation of OVP during
normal operation, Vcc should be designed to be below 19V.
3.3 Thermal Shutdown (TSD): The SenseFET and the
Fault
Situation
8V
12V
Vcc
Vds
t
Fault
occurs
Fault
removed
Normal
Operation
Normal
Operation
Power
On
V
FB
t
2.5V
6.0V
Over Load Protection
T
12= Cfb*(6.0-2.5)/Idelay
T
1
T
2
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| FSCM0565RD | 制造商:Fairchild Semiconductor Corporation 功能描述:POWER SWITCH SMPS GREEN D2-PAK-5 |
| FSCM0565RG | 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:Green Mode Fairchild Power Switch |
| FSCM0565RGTU | 功能描述:IC SWIT PWM GREEN CM HV TO220 RoHS:是 類別:集成電路 (IC) >> PMIC - AC-DC 轉換器，離線開關 系列:- 標準包裝:1 系列:FPS™ 輸出隔離:隔離 頻率范圍:61kHz ~ 73kHz 輸入電壓:8 V ~ 26 V 輸出電壓:650V 功率（瓦特）:12W 工作溫度:-40°C ~ 115°C 封裝/外殼:8-DIP（0.300"，7.62mm） 供應商設備封裝:8-MDIP 包裝:Digi-Reel® 其它名稱:FSL206MRBNFSDKR |
| FSCM0565RGWDTU | 功能描述:電源開關 IC - 配電 FPS FOR LCD RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻（最大值）:85 mOhms 開啟時間（最大值）:400 us 關閉時間（最大值）:20 us 工作電源電壓:3.2 V to 6.5 V 電源電流（最大值）: 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:SOT-23-5 |
| FSCM0565RI | 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:Green Mode Fairchild Power Switch (FPS) |
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