收藏本站
NCP1654
http://onsemi.com
15
R
boL
 is low side resistor of the dividing resistors between
V
in
 and BO pin.
R
boU
 is upper side resistor of the dividing resistors between
V
in
 and BO pin.
Figure 37. Current Sensing
Gnd
+
R
SENSE
I
L
R
CS
I
CS
CS
V
CS
NCP1654
+

I
L
Refer to Figure 37, sense current I
cs
 is proportional to the
inductor current I
L
  as described in (Equation 11). I
L
consists of the highfrequency component (that depends on
di/dt or inductor L) and lowfrequency component (that is
I
L50
).
(eq. 11)
I
cs
+
R
SENSE
R
CS
I
L
where
R
SENSE
 is the sense resistor to sense I
L
.
R
CS
 is the offset resistor between CS pin and R
SENSE
.
Figure 38. V
control
 LowPass Filtering
+
-
V
REF
OTA
6
5
V
control
?0 mA
V
out
+
+
V
CONTROL(min)
To Vm Pin
V
fb
R
Z
C
Z
C
P
R
fbL
R
fbU
V
in
Refer to Figure 38, the Operational Transconductance
Amplifier (OTA) senses V
out
  via the feedback resistor
dividers, R
fbU
 and R
fbL
. The OTA constructs a control
voltage, V
control
, depending on the output power and hence
V
out
.   The   operating   range   of   V
control
   is   from
V
CONTROL(min)
  to V
CONTROL(max)
. The signal used for
PFC duty modulation is after decreasing a offset voltage,
V
CONTROL(min)
, i.e. V
control
V
CONTROL(min)
.
This control current I
control
 is a roughly constant current
that comes from the PFC output voltage V
out
 that is a slowly
varying   signal.   The   bandwidth   of   I
control
   can   be
additionally limited by inserting the external type2
compensation components (that are R
Z
, C
Z
, and C
P
 as
shown in Figure 38). It is recommended to limit f
control
, that
is the bandwidth of V
control
  (or I
control
), below 20 Hz
typically to achieve power factor correction purpose.
The transformer of V
out
 to V
control
 is as described in
(Equation 12) if C
Z
 is >> C
P
. G
EA
 is the error amplifier gain.
V
control
V
out
+
R
fbL
@ G
EA
R
Z
R
fbL
) R
fbU
@
1 ) sR
Z
C
Z
sR
Z
C
Z
(1 ) sR
Z
C
P
)
(eq. 12)
From (Equation 7)  (Equation 11), the input impedance
Z
in
 is reformulated in (Equation 13).
Z
in
+
2
R
M
R
SENSE
V
out
V
ac
K
BO
I
L
2pR
CS
@ (V
control
* V
CONTROL(min)
) @ V
REF
I
L*50
(eq. 13)
When I
L
 is equal to I
L50
, (Equation 13) is reformulated
in (Equation 14)
Z
in
+
2
R
M
R
SENSE
V
out
V
ac
K
BO
2pR
CS
@ (V
control
* V
CONTROL(min)
) @ V
REF
(eq. 14)
The multiplier capacitor C
M
  is the one to filter the
highfrequency component of the multiplier voltage V
m
.
The highfrequency component is basically coming from
the inductor current I
L
. On the other hand, the filter
capacitor C
filter
  similarly removes the highfrequency
component of inductor current I
L
. If the capacitors C
M
 and
C
filter
 match with each other in terms of filtering capability,
I
L
 becomes I
L50
. Input impedance Z
in
 is roughly constant
over the bandwidth of 50 or 60 Hz and power factor is
corrected.
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
NCP1927DR2G IC CTLR PFC/FLYBACK 16-SOIC
NCP380HMU21AATBG IC CURRENT LIMIT SWITCH 6-UDFN
NCT1008DMT3R2G TMP DIO MON/SMBUS 4CH 8WDFN
NCT210RQR2G IC TEMP SENSOR LOC/REM 16QSOP
NCT214MT3R2G IC TEMP SENSOR LOC/REM 10WDFN
NCT72CMNR2G IC REMOTE THERMAL SENSOR 8-DFN
NCT7491RQR2G IC REMOTE THERMAL MONITOR 24QSOP
NCT75MNR2G IC SENSOR TEMP DGTL 8DFN
相关代理商/技术参数
NCP1654BD200R2G 功能描述:功率因数校正 IC NCP1654 - 200KHZ RoHS:否 制造商:Fairchild Semiconductor 开关频率:300 KHz 最大功率耗散: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
NCP1654BD65R2G 功能描述:功率因数校正 IC NCP1654-65K-B-SOIC RoHS:否 制造商:Fairchild Semiconductor 开关频率:300 KHz 最大功率耗散: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
NCP1654BP65G 功能描述:功率因数校正 IC NCP1654-65K-B-PDIP RoHS:否 制造商:Fairchild Semiconductor 开关频率:300 KHz 最大功率耗散: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
NCP1654PFCGEVB 功能描述:电源管理IC开发工具 NCP1654 PWR FACT CONT EVB RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
NCP1729-SKT 制造商:P&S 功能描述:Sample Kit, including Two NCP1729SN35T1 and A Development Source CD-ROM 制造商:P&S 功能描述:Sample Kit,including Two NCP1729SN35T1 and A Development Source CD-ROM
NCP1729SN35T1 功能描述:电荷泵 Switched Cap Voltage RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube
NCP1729SN35T1G 功能描述:电荷泵 Switched Cap Voltage Inverter w/Shutdown RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube
NCP1729SN35T1G 制造商:ON Semiconductor 功能描述:Power Supply IC