参数资料
型号: FSD146MRBN
厂商: Fairchild Semiconductor
文件页数: 11/16页
文件大小: 0K
描述: IC FPS POWER SWITCH 650V 8-MDIP
标准包装: 50
系列: FPS™
输出隔离: 隔离
频率范围: 61kHz ~ 73kHz
输入电压: 13 V ~ 23 V
输出电压: 650V
功率(瓦特): 35W
工作温度: -40°C ~ 125°C
封装/外壳: *
供应商设备封装: *
包装: *
4.3. Output-Short Protection (OSP) : If the output is
shorted, steep current with extremely high di/dt can
flow through the SenseFET during the minimum turn-
on time. Such a steep current brings high-voltage
stress on the drain of the SenseFET when turned off.
OSP protects the device from this abnormal condition.
It is comprised of detecting V FB and SenseFET turn-
on time. When the V FB is higher than 2.0V and the
SenseFET turn-on time is lower than 1.0 μ s, this
condition is recognized as an abnormal error and
PWM switching shuts down until V CC reaches V START
again. An abnormal condition output short is shown in
Figure 22.
5. Soft Burst-Mode Operation : To minimize power
dissipation in Standby Mode, the FSD146MRBN enters
Burst-Mode operation. As the load decreases, the
feedback voltage decreases. As shown in Figure 23, the
device automatically enters Burst Mode when the
feedback voltage drops below V BURL (350mV). At this
point, switching stops and the output voltages start to
drop at a rate dependent on the standby current load.
This causes the feedback voltage to rise. Once it
passes V BURH (500mV), switching resumes. The
feedback voltage then falls and the process repeats.
Burst Mode alternately enables and disables switching
of the SenseFET, thereby reducing switching loss in
Standby Mode.
Figure 22. Output-Short Protection
4.4 Over-Voltage Protection (OVP):
If the
secondary-side feedback circuit malfunctions or a
solder defect causes an opening in the feedback path,
the current through the opto-coupler transistor
becomes almost zero. Then V FB climbs up in a similar
manner to the overload situation, forcing the preset
maximum current to be supplied to the SMPS until the
overload protection is triggered. Because more
energy than required is provided to the output, the
output voltage may exceed the rated voltage before
the overload protection is triggered, resulting in the
breakdown of the devices in the secondary side. To
prevent this situation, an OVP circuit is employed. In
general, the V CC is proportional to the output voltage
and the FSD146MRBN uses V CC instead of directly
monitoring the output voltage. If V CC exceeds 24.5V,
an OVP circuit is triggered, resulting in the termination
Figure 23. Burst Mode Operation
6. Random Frequency Fluctuation (RFF) : Fluctuating
switching frequency of an SMPS can reduce EMI by
spreading the energy over a wide frequency range. The
amount of EMI reduction is directly related to the
switching frequency variation, which is limited internally.
The switching frequency is determined randomly by
external feedback voltage and internal free-running
oscillator at every switching instant. RFF effectively
scatters the EMI noise around typical switching
frequency (67kHz) and can reduce the cost of the input
filter used to meet EMI requirements (e.g. EN55022).
of the switching operation. To avoid undesired
activation of OVP during normal operation, V CC should
be designed to be below 24.5V.
4.5 Thermal Shutdown (TSD) : The SenseFET and
the control IC on a die in one package make it easier
for the control IC to detect the over temperature of the
SenseFET. If the temperature exceeds ~135 ? C, the
thermal shutdown is triggered and stops operation.
The FSD146MRBN operates in auto-restart mode
until the temperature decreases to around 75 ? C,
when normal operation resumes.
Figure 24. Random Frequency Fluctuation
? 2011 Fairchild Semiconductor Corporation
FSD146MRBN ? Rev. 1.0.0
11
www.fairchildsemi.com
相关PDF资料
PDF描述
FSD156MRBN IC FPS POWER SWITCH 650V 8-MDIP
FSD176MRTUDTU IC OFF-LINE SWITCH PWM TO220-6
FSDL321 IC SWIT PWM GREEN CM OVP HV 8DIP
FSDM0565RBIWDTU IC SWIT PWM GREEN CM HV I2PAK
FSDM0565RELDTU IC PWM/SENSEFET 650V TO-220F-6
相关代理商/技术参数
参数描述
FSD156MRBN 功能描述:软开关 PWM 控制器 SER BOOST LED DRVR RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
FSD-15A 制造商:OPTIFUSE 功能描述:
FSD176MRT 制造商:FAIRCHILD 制造商全称:Fairchild Semiconductor 功能描述:Green-Mode Fairchild Power Switch (FPSa?¢)
FSD176MRTLDTU 功能描述:软开关 PWM 控制器 AUDIO AMP BOOST REGULATOR RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
FSD176MRTUDTU 功能描述:软开关 PWM 控制器 PT5 150V/20V NCH POWERTRENCH MOSFET RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel