欢迎访问ic37.com |
会员登录 免费注册
发布采购

MCP1825-5002E/ET 参数 Datasheet PDF下载

MCP1825-5002E/ET图片预览
型号: MCP1825-5002E/ET
PDF下载: 下载PDF文件 查看货源
内容描述: 500毫安,低电压,低静态电流LDO稳压器 [500 mA, Low Voltage, Low Quiescent Current LDO Regulator]
分类和应用: 线性稳压器IC调节器电源电路输出元件
文件页数/大小: 38 页 / 631 K
品牌: MICROCHIP [ MICROCHIP ]
 浏览型号MCP1825-5002E/ET的Datasheet PDF文件第17页浏览型号MCP1825-5002E/ET的Datasheet PDF文件第18页浏览型号MCP1825-5002E/ET的Datasheet PDF文件第19页浏览型号MCP1825-5002E/ET的Datasheet PDF文件第20页浏览型号MCP1825-5002E/ET的Datasheet PDF文件第22页浏览型号MCP1825-5002E/ET的Datasheet PDF文件第23页浏览型号MCP1825-5002E/ET的Datasheet PDF文件第24页浏览型号MCP1825-5002E/ET的Datasheet PDF文件第25页  
MCP1825/MCP1825S  
The maximum power dissipation capability for a  
package can be calculated given the junction-to-  
ambient thermal resistance and the maximum ambient  
temperature for the application. Equation 5-4 can be  
used to determine the package maximum internal  
power dissipation.  
5.3  
Typical Application  
Internal power dissipation, junction temperature rise,  
junction temperature and maximum power dissipation  
is calculated in the following example. The power  
dissipation as a result of ground current is small  
enough to be neglected.  
EQUATION 5-4:  
5.3.1  
POWER DISSIPATION EXAMPLE  
(TJ(MAX) TA(MAX)  
)
PD(MAX) = ---------------------------------------------------  
RθJA  
Package  
Package Type = TO-220-5  
PD(MAX) = Maximum device power dissipation  
Input Voltage  
TJ(MAX) = maximum continuous junction  
temperature  
V
IN = 3.3V ± 5%  
LDO Output Voltage and Current  
TA(MAX) = maximum ambient temperature  
V
OUT = 2.5V  
RθJA = Thermal resistance from junction-to-  
I
OUT = 500 mA  
ambient  
Maximum Ambient Temperature  
A(MAX) = 60°C  
Internal Power Dissipation  
T
EQUATION 5-5:  
TJ(RISE) = PD(MAX) × RθJA  
PLDO(MAX) = (VIN(MAX) – VOUT(MIN)) x IOUT(MAX)  
PLDO = ((3.3V x 1.05) – (2.5V x 0.975))  
x 500 mA  
TJ(RISE) = Rise in device junction temperature  
over the ambient temperature  
PLDO = 0.514 Watts  
PD(MAX) = Maximum device power dissipation  
RθJA = Thermal resistance from junction-to-  
5.3.1.1  
Device Junction Temperature Rise  
ambient  
The internal junction temperature rise is a function of  
internal power dissipation and the thermal resistance  
from junction-to-ambient for the application. The  
thermal resistance from junction-to-ambient (RθJA) is  
derived from EIA/JEDEC standards for measuring  
thermal resistance. The EIA/JEDEC specification is  
JESD51. The standard describes the test method and  
board specifications for measuring the thermal  
resistance from junction to ambient. The actual thermal  
EQUATION 5-6:  
TJ = TJ(RISE) + TA  
TJ = Junction temperature  
TJ(RISE) = Rise in device junction temperature  
over the ambient temperature  
TA = Ambient temperature  
resistance for a particular application can vary  
depending on many factors such as copper area and  
thickness. Refer to AN792, “A Method to Determine  
How Much Power a SOT23 Can Dissipate in an  
Application” (DS00792), for more information regarding  
this subject.  
TJ(RISE) = PTOTAL x RθJA  
TJRISE = 0.514 W x 29.3° C/W  
TJRISE = 15.06°C  
© 2008 Microchip Technology Inc.  
DS22056B-page 21