參數(shù)資料
型號(hào): FSCM0765RC
廠商: FAIRCHILD SEMICONDUCTOR CORP
元件分類: 穩(wěn)壓器
英文描述: Green Mode Fairchild Power Switch (FPS)
中文描述: 21 A SWITCHING REGULATOR, 72 kHz SWITCHING FREQ-MAX, PSFM6
封裝: TO-220, 6 PIN
文件頁數(shù): 12/20頁
文件大?。?/td> 495K
代理商: FSCM0765RC
FSCM0765R
12
3.3 Thermal Shutdown (TSD):
The SenseFET and the
control IC are built in one package. This makes it easy for
the control IC to detect the heat generation from the
SenseFET. When the temperature exceeds approximately
145
°
C, the thermal protection is triggered resulting in
shutdown of the FPS.
4. Frequency Modulation
: EMI reduction can be
accomplished by modulating the switching frequency of a
switched power supply. Frequency modulation can reduce
EMI by spreading the energy over a wider frequency range
than the band width measured by the EMI test equipment.
The amount of EMI reduction is directly related to the depth
of the reference frequency. As can be seen in Figure 21, the
frequency changes from 63KHz to 69KHz in 4ms.
Figure 21. Frequency Modulation
5. Soft Start
: The FSCM0765R has an internal soft start
circuit that increases PWM comparator inverting input
voltage together with the SenseFET current slowly after it
starts up. The typical soft start time is 15ms. The pulse width
to the power switching device is progressively increased to
establish the correct working conditions for transformers,
rectifier diodes and capacitors. The voltage on the output
capacitors is progressively increased with the intention of
smoothly establishing the required output voltage.
Preventing transformer saturation and reducing stress on the
secondary diode during start up is also helpful.
6. Burst Operation:
To minimize power dissipation in
standby mode, the FSCM0765R enters into burst mode
operation at light load condition. As the load decreases, the
feedback voltage decreases. As shown in Figure 22, the
device automatically enters into burst mode when the
feedback voltage drops below VBL (300mV). At this point
switching stops and the output voltages start to drop at a rate
dependent on standby current load. This causes the feedback
voltage to rise. Once it passes VBH (500mV)
,
switching
resumes. The feedback voltage then falls
,
and the process
repeats. Burst mode operation alternately enables and
disables switching of the power SenseFET
,
thereby reducing
switching loss in standby mode.
Figure 22. Waveforms of Burst Operation
T
s
T
s
T
s
Drain Current
f
s
63kHz
66kHz
4ms
t
V
FB
Vds
0.3V
0.5V
Ids
Vo
Vo
set
time
Switching
disabled
T1
T2 T3
Switching
disabled
T4
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
FSCM0765RCYDTU 功能描述:電源開關(guān) IC - 配電 SMPS Power Switch 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(shí)間(最大值):400 us 關(guān)閉時(shí)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(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-5
FSCM0765RD 功能描述:電源開關(guān) IC - 配電 SMPS Power Switch 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(shí)間(最大值):400 us 關(guān)閉時(shí)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(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-5
FSCM0765RG 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:Green Mode Fairchild Power Switch
FSCM0765RGWDTU 功能描述:電源開關(guān) IC - 配電 SMPS POWER SWITCH POWER SWITCH GREEN 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(shí)間(最大值):400 us 關(guān)閉時(shí)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(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-5
FSCM0765RI 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:Green Mode Fairchild Power Switch (FPS)