参数资料
| 型号： | FAN100MY |
| 厂商： | Fairchild Semiconductor |
| 文件页数： | 10/16页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM GREEN CV/CC 8SOP |
| 标准包装： | 1 |
| 输出隔离： | 隔离 |
| 频率范围： | 39 ~ 45kHz |
| 输入电压： | 5.5 V ~ 15 V |
| 输出电压： | 30V |
| 功率（瓦特）： | 660mW |
| 工作温度： | -40°C ~ 125°C |
| 封装/外壳： | 8-SOIC（0.154"，3.90mm 宽） |
| 供应商设备封装： | 8-SOP |
| 包装： | 标准包装 |
| 其它名称： | FAN100MYDKR |
Functional Description
side regulated flyback converter and its typical
Of the two error voltages, V COMV and V COMI , the smaller
determines the duty cycle. During constant voltage
waveforms
are
shown
in
Generally,
regulation mode, V COMV determines the duty cycle while
discontinuous conduction mode (DCM) operation is
preferred for primary-side regulation since it allows
better output regulation. The operation principles of
DCM flyback converter are as follows:
V COMI is saturated to HIGH. During constant current
regulation mode, V COMI determines the duty cycle while
V COMV is saturated to HIGH.
During the MOSFET on time (t ON ), input voltage (V DL ) is
applied across the primary side inductor (L m ). Then,
MOSFET current (I ds ) increases linearly from zero to the
peak value (I pk ). During this time, the energy is drawn
from the input and stored in the inductor.
V AC
+
V DL
-
N p :N s
L m
I D
D
+ V F -
I o
+
V O
-
L
O
A
D
When the MOSFET is turned off, the energy stored in
applied across the secondary-side inductor ( L m × N s /
N p ) and the diode current (I D ) decreases linearly from
the inductor forces the rectifier diode (D) to be turned
on. While the diode is conducting, the output voltage
(V o ), together with diode forward-voltage drop (V F ), is
2
2
the peak value (I pk × N p /N s ) to zero. At the end of
Gate
EA_I
V COMI
PWM
Control
Ref
I O
Estimator
t DIS
Detector
CS
VS
R CS
I ds
inductor current discharge time (t DIS ), all the energy
stored in the inductor has been delivered to the output.
When the diode current reaches zero, the transformer
V COMV
EA_V
V O
Estimator
Ref
VDD
R S1
N A
+
V w
auxiliary winding voltage (V w ) begins to oscillate by the
Primary-Side Regulation
R S2
-
resonance between the primary-side inductor (L m ) and
the effective capacitor loaded across the MOSFET.
During the inductor current discharge time, the sum of
output voltage and diode forward-voltage drop is
reflected to the auxiliary winding side as (V o +V F ) × N a /N s .
Since the diode forward-voltage drop decreases as
current decreases, the auxiliary winding voltage reflects
the output voltage best at the end of diode conduction
time where the diode current diminishes to zero. Thus,
by sampling the winding voltage at the end of the diode
conduction time, the output voltage information can be
Controller
Figure 23. Simplified PSR Flyback Converter Circuit
I DS (MOSFET Drain-to-Source
Current)
I pk
obtained. The internal error amplifier for output voltage
regulation (EA_V) compares the sampled voltage with
internal precise reference to generate error voltage
(V COMV ), which determines the duty cycle of the
MOSFET in CV mode.
I D (Diode Current)
I pk ?
N P
N S
I D . avg = I o
Meanwhile, the output current can be estimated using
the peak drain current and inductor current discharge
time since output current is the same as average of the
V w (Auxiliary Winding Voltage)
diode current in steady state.
The output current estimator detects the peak value of
the drain current with a peak detection circuit and
calculates the output current using the inductor
V F ?
N A
N S
V O ?
N A
N S
discharge time (t DIS ) and switching period (t s ). This
output information is compared with the internal precise
reference to generate error voltage (V COMI ), which
determines the duty cycle of the MOSFET in CC mode.
With Fairchild’s
innovative technique,
t ON
t DIS
TRUECURRENT?, constant current (CC) output can
be precisely controlled.
? 2009 Fairchild Semiconductor Corporation
FAN100 Rev. 1.0.3
10
t S
Figure 24. Key Waveforms of DCM Flyback
Converter
www.fairchildsemi.com
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相关代理商/技术参数 |
参数描述 |
|---|---|
| FAN102 | 制造商:FAIRCHILD 制造商全称:Fairchild Semiconductor 功能描述:Primary-Side-Control PWM Controller |
| FAN102_09 | 制造商:FAIRCHILD 制造商全称:Fairchild Semiconductor 功能描述:Primary-Side-Control PWM Controller |
| FAN102MY | 功能描述:电流型 PWM 控制器 30V, 45kHz, PSR PWM Controller 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 |
| FAN102MYTR | 制造商:Rochester Electronics LLC 功能描述: 制造商:Fairchild Semiconductor Corporation 功能描述: |
| FAN103 | 制造商:Fairchild 功能描述:5W~10W Mobile Charger |
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