收藏本站
NCP3011, NCV3011
I G1
I G2
where:
Q GD Q GD
t ON + + (eq. 32)
V BST * V TH R HSPU ) R G
and:
Q GD Q GD
t OFF + + (eq. 33)
V BST * V TH R HSPD ) R G
Next, the MOSFET output capacitance losses are caused
by both the control and synchronous MOSFET but are
dissipated only in the control MOSFET.
2
P DS + 1 @ Q OSS @ V IN @ f SW (eq. 34)
Finally the loss due to the reverse recovery time of the
body diode in the synchronous MOSFET is shown as
follows:
P RR + Q RR @ V IN @ f SW (eq. 35)
The low ? side or synchronous MOSFET turns on into zero
volts so switching losses are negligible. Its power
dissipation only consists of conduction loss due to R DS(on)
and body diode loss during the non ? overlap periods.
P D_SYNC + P COND ) P BODY (eq. 36)
Conduction loss in the low ? side or synchronous
MOSFET is described as follows:
2
P COND + I RMS_SYNC @ R DS(on)_SYNC (eq. 37)
I G1 : output current from the high ? side gate drive (HSDR)
I G2 : output current from the low ? side gate drive (LSDR)
? SW : switching frequency of the converter.
V BST : gate drive voltage for the high ? side drive, typically
7.5 V.
Q GD : gate charge plateau region, commonly specified in the
MOSFET datasheet
V TH : gate ? to ? source voltage at the gate charge plateau
region
Q OSS : MOSFET output gate charge specified in the data
sheet
Q RR : reverse recovery charge of the low ? side or
synchronous MOSFET, specified in the datasheet
R DS(on)_CONTROL : on resistance of the high ? side, or
control, MOSFET
R DS(on)_SYNC : on resistance of the low ? side, or
synchronous, MOSFET
NOL LH : dead time between the LSDR turning off and the
HSDR turning on, typically 85 ns
NOL HL : dead time between the HSDR turning off and the
LSDR turning on, typically 75 ns
Once the MOSFET power dissipations are determined,
the designer can calculate the required thermal impedance
for each device to maintain a specified junction temperature
at the worst case ambient temperature. The formula for
calculating the junction temperature with the package in free
air is:
( 1 * D) @ 1 )
I RMS_SYNC + I OUT @
where:
ra 2
12
The body diode losses can be approximated as:
P BODY + V FD @ I OUT @ f SW @ NOL LH ) NOL HL
Vth
(eq. 38)
(eq. 39)
T J + T A ) P D @ R q JA
T J : Junction Temperature
T A : Ambient Temperature
P D : Power Dissipation of the MOSFET under analysis
R q JA : Thermal Resistance Junction ? to ? Ambient of the
MOSFET’s package
As with any power design, proper laboratory testing
should be performed to insure the design will dissipate the
required power under worst case operating conditions.
Variables considered during testing should include
maximum ambient temperature, minimum airflow,
maximum input voltage, maximum loading, and component
variations (i.e. worst case MOSFET R DS(on) ).
Figure 43. MOSFET Switching Characteristics
http://onsemi.com
24
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
MIC2505BM IC SW HIGH SIDE SGL 2A 8SOIC
MIC2505-2BM IC SW HIGH SIDE SGL 2A 8SOIC
MIC2505-1BM IC SW HIGH SIDE SGL 2A 8SOIC
TAAB106K020G CAP TANT 10UF 20V 10% AXIAL
MC34063LBBEVB EVAL BOARD FOR MC34063LBB
A9BAG-0502F FLEX CABLE - AFF05G/AF05/AFE05T
EBM08DTMD-S189 CONN EDGECARD 16POS R/A .156 SLD
RCM06DSUI CONN EDGECARD 12POS DIP .156 SLD
相关代理商/技术参数
NCP3012 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Synchronous PWM Controller
NCP3012DTBR2G 功能描述:电压模式 PWM 控制器 Single Output Buck 0.8V to 40V 70uA RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
NCP301HSN09T1 功能描述:电压监测器/监控器 0.9V Detector RoHS:否 制造商:Texas Instruments 监测电压数:2 监测电压:Adjustable 输出类型:Open Drain 欠电压阈值: 过电压阈值: 准确性:1 % 工作电源电压:1.5 V to 6.5 V 工作电源电流:1.8 uA 最大工作温度:+ 125 C 封装 / 箱体:SON-6 安装风格:SMD/SMT
NCP301HSN09T1G 功能描述:电压监测器/监控器 0.9V Detector w/Reset High RoHS:否 制造商:Texas Instruments 监测电压数:2 监测电压:Adjustable 输出类型:Open Drain 欠电压阈值: 过电压阈值: 准确性:1 % 工作电源电压:1.5 V to 6.5 V 工作电源电流:1.8 uA 最大工作温度:+ 125 C 封装 / 箱体:SON-6 安装风格:SMD/SMT
NCP301HSN10T1 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Voltage Detector Series
NCP301HSN11T1 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Voltage Detector Series
NCP301HSN12T1 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Voltage Detector Series
NCP301HSN13T1 制造商:ONSEMI 制造商全称:ON Semiconductor 功能描述:Voltage Detector Series