参数资料
| 型号： | FSDM311A |
| 厂商： | Fairchild Semiconductor |
| 文件页数： | 10/12页 |
| 文件大小： | 0K |
| 描述： | IC FPS PWM/SENSFET 650V 8DIP |
| 标准包装： | 50 |
| 输出隔离： | 隔离 |
| 频率范围： | 61 ~ 73kHz |
| 输入电压： | 7 V ~ 20 V |
| 输出电压： | 650V |
| 功率（瓦特）： | 13W |
| 工作温度： | 25°C ~ 150°C |
| 封装/外壳： | 8-DIP（0.300"，7.62mm） |
| 供应商设备封装： | 8-DIP |
| 包装： | 管件 |
Application Information
Methods of Reducing Audible Noise
Switching-mode power converters have electronic and
magnetic components that generate audible noise when
the operating frequency is in the range of 20~20,000Hz.
Even though they operate above 20kHz, they can make
noise, depending on the load condition. Designers can
employ several methods to reduce noise.
Glue or Varnish
The most common method involves using glue or
varnish to tighten magnetic components. The motion of
core, bobbin, and coil; and the chattering or
magnetostriction of core, can cause the transformer to
produce audible noise. The use of rigid glue and
varnish helps reduce transformer noise, but can crack
the core. This is because sudden changes in the
ambient temperature cause the core and the glue to
expand or shrink at a different rate.
Ceramic Capacitor
Using a film capacitor instead of a ceramic capacitor as
a snubber capacitor is another noise-reduction solution.
Some dielectric materials show a piezoelectric effect,
depending on the electric field intensity. A snubber
capacitor becomes one of the most significant sources
of audible noise. It is possible to use a Zener clamp
circuit instead of an RCD snubber for higher efficiency
as well as lower audible noise.
Figure 23.
Equal Loudness Curves
Adjusting Sound Frequency
Moving the fundamental frequency out of the 2~4kHz
range another method of reducing perceptible noise.
Generally, humans are more sensitive to noise in the
range of 2~4kHz. When the fundamental frequency of
noise is located in this range, it is perceived as louder,
although the noise intensity level is identical (refer to
Figure 23, Equal Loudness Curves) .
If burst-mode operation is suspected to be a source of
noise, this method may be helpful. If the frequency of
burst-mode operation lies between 2~4 kHz, adjusting
the feedback loop can shift the frequency. To reduce
the burst operation frequency, increase a feedback gain
capacitor (C F ), opto-coupler supply resistor (R D ), and
feedback capacitor (C B ); and decrease a feedback gain
resistor (R F ), as shown in Figure 24.
? 2007 Fairchild Semiconductor Corporation
FSDM311A ? Rev.1.0.2
Figure 24. Typical Feedback Network of FPS?
Reference Materials
AN-4134: Design Guidelines for Off-line Forward
Converters Using Fairchild Power Switch (FPS?)
AN-4137: Design Guidelines for Off-line Flyback
Converters Using Fairchild Power Switch (FPS?)
AN-4138: Design Considerations for Battery Charger
Using Green Mode Fairchild Power Switch (FPS?)
AN-4140: Transformer Design Consideration for Off-
line Flyback Converters Using Fairchild Power Switch
(FPS?)
AN-4141: Troubleshooting and Design Tips for
Fairchild Power Switch (FPS?) Flyback Applications
AN-4147: Design Guidelines for RCD Snubber of
Flyback
AN-4148: Audible Noise Reduction Techniques for
FPS? Applications
www.fairchildsemi.com
10
相关PDF资料 |
PDF描述 |
|---|---|
| FSEZ1016AMY | IC PWM PRIMARY REG MOSFET 7-SOIC |
| FSEZ1216BNY | IC PWM CTLR MOSFET 8-DIP |
| FSEZ1216NY | IC PWM PRIMARY REG MOSFET 8-DIP |
| FSEZ1307MY | IC PWM CTLR PRIMARY REG 7-SOIC |
| FSEZ1317AMY | IC PWM CTLR PRIMARY REG 7-SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| FSDM311L | 功能描述:电源开关 IC - 配电 SMPS PS for PC TV and Mont Aux Power RoHS:否 制造商:Exar 输出端数量:1 开启电阻（最大值）:85 mOhms 开启时间（最大值）:400 us 关闭时间（最大值）:20 us 工作电源电压:3.2 V to 6.5 V 电源电流（最大值）: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOT-23-5 |
| FSDM3-125M | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Delay Line |
| FSDM3-15M | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Delay Line |
| FSDM3-20M | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Delay Line |
| FSDM3-250M | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Delay Line |
发布紧急采购，3分钟左右您将得到回复。