参数资料
型号: NCV4275ADT33RKG
厂商: ON SEMICONDUCTOR
元件分类: 固定正电压单路输出LDO稳压器
英文描述: 450 mA, 3.3 V, LDO w/Reset and Delay
中文描述: 3.3 V FIXED POSITIVE LDO REGULATOR, 1.17 V DROPOUT, PSSO4
封装: LEAD FREE, DPAK-5
文件页数: 3/19页
文件大小: 164K
代理商: NCV4275ADT33RKG
NCV4275A
http://onsemi.com
11
Calculating Power Dissipation
in a Single Output Linear Regulator
The maximum power dissipation for a single output
regulator (Figure 25) is:
PD(max) + [VI(max) * VQ(min)]IQ(max)
(1)
) VI(max)Iq
where
VI(max)
is the maximum input voltage,
VQ(min)
is the minimum output voltage,
IQ(max)
is the maximum output current for the
application,
Iq
is the quiescent current the regulator
consumes at IQ(max).
Once the value of PD(max) is known, the maximum
permissible value of RqJA can be calculated:
RqJA +
150° C * TA
PD
(2)
The value of RqJA can then be compared with those in the
package section of the data sheet. Those packages with
RqJA’s less than the calculated value in Equation 2 will keep
the die temperature below 150
°C.
In some cases, none of the packages will be sufficient to
dissipate the heat generated by the IC, and an external
heatsink will be required.
SMART
REGULATOR
Iq
Control
Features
IQ
II
Figure 25. Single Output Regulator with Key
Performance Parameters Labeled
VI
VQ
}
Heatsinks
A heatsink effectively increases the surface area of the
package to improve the flow of heat away from the IC and
into the surrounding air.
Each material in the heat flow path between the IC and
the outside environment will have a thermal resistance.
Like series electrical resistances, these resistances are
summed to determine the value of RqJA:
RqJA + RqJC ) RqCS ) RqSA
(3)
where
RqJC is the junctiontocase thermal resistance,
RqCS is the casetoheatsink thermal resistance,
RqSA is the heatsinktoambient thermal
resistance.
RqJC appears in the package section of the data sheet.
Like RqJA, it too is a function of package type. RqCS and
RqSA are functions of the package type, heatsink and the
interface between them. These values appear in heatsink
data sheets of heatsink manufacturers.
Thermal, mounting, and heatsinking considerations are
discussed in the ON Semiconductor application note
AN1040/D.
相关PDF资料
PDF描述
NCV4275ADT50RKG 450 mA, 5.0V, LDO w/Reset and Delay
NCV4275TRKG 5 V FIXED POSITIVE LDO REGULATOR, 0.5 V DROPOUT, PSSO4
NCV4279A50D1G 5 V / 150 mA LDO w/ Reset, Delay, Adjustable Reset and Early Warning
NCV4279A50D1R2G 5 V / 150 mA LDO w/ Reset, Delay, Adjustable Reset and Early Warning
NCV4279CD1R2 5 V FIXED POSITIVE LDO REGULATOR, 0.6 V DROPOUT, PDSO8
相关代理商/技术参数
参数描述
NCV4275ADT50RKG 功能描述:低压差稳压器 - LDO 450 mA LDO 5V RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
NCV4275ADT50RKG/H 制造商:ON Semiconductor 功能描述:
NCV4275DS 功能描述:低压差稳压器 - LDO 5V 450mA RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
NCV4275DSG 功能描述:低压差稳压器 - LDO 5V 450mA RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20
NCV4275DSR4 功能描述:低压差稳压器 - LDO 5V 450mA RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压(最大值):307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20