参数资料
型号: NCP1910GEVB
厂商: ON Semiconductor
文件页数: 24/37页
文件大小: 0K
描述: BOARD DEMO NCP1910DEMO-B-TLS
设计资源: NCP1910 Schematic
NCP1910GEVB BOM
标准包装: 1
主要目的: DC/DC,步降
输出及类型: 1,非隔离
输出电压: 最低可调至 0.8V
电流 - 输出: 3A
输入电压: 3 ~ 5.5 V
稳压器拓扑结构: 降压
频率 - 开关: 1MHz
板类型: 完全填充
已供物品:
已用 IC / 零件: NCP1910
其它名称: NCP1910GEVBOS
NCP1910
? V ac,on is the rms ac voltage to starts PFC operating.
? V ac,off the rms ac voltage for line brown ? out
detection.
PFC Current Sense
I L
PFC Over ? Power Limitation (OPL)
This is a second OCP with a threshold that is line
dependent. Sense current I CS represents the inductor current
I L and hence represents the input current approximately.
Input voltage signal V LBO represents the rms input voltage.
The product (I CS x V LBO ) represents an approximated input
power (I L x V ac ). It is illustrated in Figure 48.
R CS
I CS CS
NCP1910
V in
I L
+
GND
R SENSE
I L
V CS
?
R SENSE
I CS + I L
I CS
R LBOU
R LBOL
Figure 47. PFC Current Sensing Configuration
The device senses the inductor current I L by the current
sense scheme in Figure 47. The device maintains the voltage
at CS pin to be zero voltage, i.e. V CS = 0 V, so that
R SENSE
(eq. 13)
R CS
Where:
? R SENSE is the sense resistor to sense I L .
? R CS is the offset resistor between CS pin and
R SENSE .
This scheme has the advantage of the minimum number
of components for current sensing. The sense current I CS
represents the inductor current I L and will be used in the PFC
duty modulation to generate the multiplier voltage V M ,
Over ? Power Limitation (OPL), and Over ? Current
Protection. Equation 13 would insist in the fact that it
provides the flexibility in the R SENSE choice and that it
allows to detect in ? rush currents.
R CS
CS
Current
mirror
LBO OPL
> 275 m VA?
C LBO
Figure 48. PFC Over ? Power Limitation Configuration
When the product (I CS x V LBO ) is greater than a
permissible level 275 m VA, the device turns off the PFC
driver so that the input power is limited. The OPL is
automatically deactivated when the product (I CS x V LBO ) is
lower than the 275 m VA level. This 275 m VA level
corresponds to the approximated input power (I L x Vac) to
be smaller than the particular expression in Equation 15.
I L
R CS
PFC Over ? Current Protection (OCP)
PFC Over ? Current Protection is reached when I CS is
larger than I S(OCP) (200 m A typical). The offset voltage of
the CS pin is typical 10 mV and it is neglected in the
calculation. Hence, the maximum OCP inductor current
I CS V LBO t 275 m VA
R SENSE 2 2 K LBO
p
@ V ac
t 275 m VA
(eq. 15)
R CS I S OCP
R CS
R LBOU ) R LBOL
threshold I L(OCP) is obtained in Equation 14.
I L OCP + + 200 m A (eq. 14)
R SENSE R SENSE
When over ? current protection threshold is reached, the
PFC drive goes low. The device automatically resumes
operation when the inductor current goes below the
I L @ V ac t
Where
R CS @ p
R SENSE @ K LBO
K LBO +
@ 97 m VA
R LBOL
threshold.
http://onsemi.com
24
相关PDF资料
PDF描述
NCP3418BMNR2G IC MOSFET DRIVER DUAL 12V 10-DFN
NCP3418DR2 IC MOSFET DRIVER DUAL 12V 8-SOIC
NCP3420DR2G IC MOSFET DRIVER DUAL 12V 8-SOIC
NCP3488DR2G IC MOSFET DRVR DUAL 12V 8-SOIC
NCP5007SNT1 IC LED DRIVR WHT COMPACT 5TSOP
相关代理商/技术参数
参数描述
NCP1927DR2G 功能描述:功率因数校正 IC PFC AND FLYBACK CONTROLER 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
NCP1937A1DR2G 制造商:ON Semiconductor 功能描述:COMBO PFC & QUAZI FLYBACK - Tape and Reel 制造商:ON Semiconductor 功能描述:REEL / COMBO PFC & QUAZI FLYBACK
NCP1937B1DR2G 制造商:ON Semiconductor 功能描述:COMBO PFC & QUAZI FLYBACK - Tape and Reel
NCP1937BADAPGEVB 制造商:ON Semiconductor 功能描述:ADPTR 90W PFC+QR<10MW - Bulk 制造商:ON Semiconductor 功能描述:BOARD EVAL FOR NCP1937 制造商:ON Semiconductor 功能描述:Power Management IC Development Tools 90 W Adapter PFC+QR 10 MW Eval Brd
NCP21WB333 制造商:MURATA 制造商全称:Murata Manufacturing Co., Ltd. 功能描述:for Surface Mounting Application