參數(shù)資料
型號(hào)： UPC29S78
英文描述： Useage of Three-Terminal Regulators | User＇s Manual[05/2000]
中文描述： 使用三端穩(wěn)壓器|用戶手冊(cè)[05/2000]
文件頁(yè)數(shù)： 24/35頁(yè)
文件大?。?/td> 187K
代理商： UPC29S78
User’s Manual G12702EJ8V0UM00
30
<1> Design objectives
Positive power supply using
PC7805AHF
Maximum output current
IO max. = 0.6 (A)
Maximum voltage difference between input and output
VDIF max. = 6 (V)
Maximum operating ambient temperature
TA max. = 60 (
°C)
Maximum junction temperature
TJ max. = 100 (
°C)
<2> Heatsink thermal resistance calculation
In a used state, the junction temperature TJ is the following.
TJ = (Rth(J-C) +
θC-HS + θHS) PD + TA ...................................................................................................... (6.3)
Rth(J-C): Thermal resistance (junction to case)
θC-HS: Thermal resistance (case to heatsink)
θHS:
Thermal resistance of heatsink
PD:
Power dissipation
Here, TJ max. = 100 (
°C), TA max. = 60 (°C),
θC-HS << 1 (°C/W), and Rth(J-C) = 5.0 (°C/W)
By substituting PD max. = VDIF max.
× IO max. = 3.6 (W) in expression (6.3), find the thermal resistance
θHS needed
in the heatsink.
θHS =
– Rth(J-C) –
θC-HS
= 6.1 (
°C/W) .................................................................................................................................... (6.4)
<3> Determination of size of heatsink
From expression (6.4), the design objectives can be satisfied using a heatsink of 6.1 (
°C/W).
Figure 6-5 shows the relationship between the thickness, surface area, and thermal resistance of an
aluminum board.
By using a 3 mm thick 60 cm
2 aluminum board here, it can be seen that the heatsink will have the necessary
thermal resistance.
(Use example without heatsink)
The junction temperature TJ in the used state when not installing a heatsink is the following.
TJ = Rth(J-A)
PD + TA ........................................................................................................................ (6.5)
Rth(J-A): Thermal resistance (junction to ambient air) (free air)
PD:
Power dissipation
TA:
Operating ambient temperature
Setting TJ to 100
°C or less in the used state is recommended.
.
TJ – TA
PD
相關(guān)PDF資料
PDF描述
UPC3025 Useage of Three-Terminal Regulators | User＇s Manual[05/2000]
UPC1663B Analog IC
UPC1663C Analog IC
UPC1663P Analog IC
UPC1664C Analog IC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
UPC29S78GR 制造商:NEC 制造商全稱:NEC 功能描述:LOW DROPOUT VOLTAGE REGULATOR WITH ON/OFF FUNCTION
UPC29S78GR-E1-A 制造商:Renesas Electronics Corporation 功能描述:
UPC29S78H 制造商:NEC 制造商全稱:NEC 功能描述:LOW DROPOUT VOLTAGE REGULATOR WITH ON/OFF FUNCTION
UPC29S78TA 制造商:NEC 制造商全稱:NEC 功能描述:LOW DROPOUT VOLTAGE REGULATOR WITH ON/OFF FUNCTION
UPC2A23P4 制造商: 功能描述: 制造商:undefined 功能描述:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*