参数资料
| 型号： | FSQ211L |
| 厂商： | Fairchild Semiconductor |
| 文件页数： | 10/13页 |
| 文件大小： | 0K |
| 描述： | IC SWIT PWM GREEN UVLO HV 8SOP |
| 标准包装： | 4,500 |
| 输出隔离： | 隔离 |
| 频率范围： | 61 ~ 73kHz |
| 输入电压： | 8 V ~ 20 V |
| 输出电压： | 650V |
| 功率（瓦特）： | 1.4W |
| 工作温度： | 25°C ~ 145°C |
| 封装/外壳： | 8-SOP，8-LSOP |
| 供应商设备封装： | 8-LSOP |
| 包装： | 管件 |
Application Tips
Methods of Reducing Audible Noise
Switching mode power converters have electronic and
magnetic components that generate audible noises
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 the 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 option.
Some dielectric materials show a piezoelectric effect,
depending on the electric field intensity. Therefore, 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.
Adjusting Sound Frequency
Moving the fundamental frequency of noise out of
2~4kHz range is the third method. Generally, humans
are more sensitive to noise in the range of 2~4kHz.
When the fundamental frequency of noise is located in
this range, the noise is perceived as louder, although
the noise intensity level is identical ( refer to Figure 22
Equal Loudness Curves) .
When FPS acts in burst mode and the burst operation is
suspected to be a source of noise, this method may be
helpful. If the frequency of burst-mode operation lies in
the range of 2~4kHz, adjusting the feedback loop can
shift the burst operation 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 23.
? 2007 Fairchild Semiconductor Corporation
FSQ211 Rev. 1.0.0
10
Figure 22. Equal Loudness Curves
Figure 23. Typical Feedback Network of FPS?
Other 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? Application
www.fairchildsemi.com
相关PDF资料 |
PDF描述 |
|---|---|
| FSQ311L | IC SWITCH FPS LOW EMI HE 8-LSOP |
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| FSQ500L | IC SWIT PWM GREEN UVLO SOT223 |
| FSQ500N | IC PWM/SENSEFET 130KHZ 8-MDIP |
| FSQ510H | IC SWITCH FPS 0.5A 700V 8-DIP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| FSQ2W | 制造商:RFE 制造商全称:RFE international 功能描述:FUSIBLE RESISTORS FM, FKN, & FSQ Series: Fusible |
| FSQ311 | 功能描述:电流型 PWM 控制器 SMPS 1A 650V Power Switch RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| FSQ311L | 功能描述:电源开关 IC - 配电 SMPS Power Switch 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 |
| FSQ3120RJ | 功能描述:线绕电阻器 - 透孔 FSQ3 120R 5% RoHS:否 制造商:Bourns 电阻:10 Ohms 容差:5 % 功率额定值:7 W 温度系数:200 PPM / C 系列:FW 端接类型:Axial 工作温度范围:- 55 C to + 155 C 尺寸:9.5 mm Dia. x 26 mm L 封装:Ammo 产品:Power Resistors Wirewound High Energy |
| FSQ321 | 功能描述:开关变换器、稳压器与控制器 SMPS Power Switch RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel |
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