收藏本站
AN822
Vishay Siliconix
TABLE 1: EQIVALENT STEADY STATE PERFORMANCE
Package
SO-8
TSSOP-8
TSOP-8
PPAK 1212
PPAK SO-8
Configuration
Thermal Resiatance R thJC (C/W)
Single
20
Dual
40
Single
52
Dual
83
Single
40
Dual
90
Single
2.4
Dual
5.5
Single
1.8
Dual
5.5
Po w erPAK 1212
49. 8 °C
2.4 °C/ W
Standard SO- 8
8 5 °C
20 °C/ W
Standard TSSOP- 8
149 °C
52 °C/ W
TSOP-6
125 °C
40 °C/ W
PC Board at 45 °C
Figure 4. Temperature of Devices on a PC Board
THERMAL PERFORMANCE
Introduction
A basic measure of a device’s thermal performance is
the junction-to-case thermal resistance, R θ jc, or the
junction to- foot thermal resistance, R θ jf. This parameter
is measured for the device mounted to an infinite heat
sink and is therefore a characterization of the device
only, in other words, independent of the properties of the
object to which the device is mounted. Table 1 shows a
comparison of the PowerPAK 1212-8, PowerPAK SO-8,
standard TSSOP-8 and SO-8 equivalent steady state
performance.
By minimizing the junction-to-foot thermal resistance, the
MOSFET die temperature is very close to the tempera-
ture of the PC board. Consider four devices mounted on
a PC board with a board temperature of 45 °C (Figure 4).
Suppose each device is dissipating 2 W. Using the junc-
tion-to-foot thermal resistance characteristics of the
PowerPAK 1212-8 and the other SMT packages, die
temperatures are determined to be 49.8 °C for the Pow-
erPAK 1212-8, 85 °C for the standard SO-8, 149 °C for
standard TSSOP-8, and 125 °C for TSOP-6. This is a
4.8 °C rise above the board temperature for the Power-
PAK 1212-8, and over 40 °C for other SMT packages. A
4.8 °C rise has minimal effect on r DS(ON) whereas a rise
of over 40 °C will cause an increase in r DS(ON) as high
as 20 %.
Document Number 71681
03-Mar-06
Spreading Copper
Designers add additional copper, spreading copper, to
the drain pad to aid in conducting heat from a device. It
is helpful to have some information about the thermal
performance for a given area of spreading copper.
Figure 5 and Figure 6 show the thermal resistance of a
PowerPAK 1212-8 single and dual devices mounted on
a 2-in. x 2-in., four-layer FR-4 PC boards. The two inter-
nal layers and the backside layer are solid copper. The
internal layers were chosen as solid copper to model the
large power and ground planes common in many appli-
cations. The top layer was cut back to a smaller area and
at each step junction-to-ambient thermal resistance
measurements were taken. The results indicate that an
area above 0.2 to 0.3 square inches of spreading copper
gives no additional thermal performance improvement.
A subsequent experiment was run where the copper on
the back-side was reduced, first to 50 % in stripes to
mimic circuit traces, and then totally removed. No signif-
icant effect was observed.
www.vishay.com
3
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
SIS892ADN-T1-GE3 MOSFET N-CH 100V D-S PPAK 1212
SIS902DN-T1-GE3 MOSFET N-CH D-S 75V 1212-8 PPAK
SISA10DN-T1-GE3 MOSFET N-CH 30V 30A 1212-8
SIZ700DT-T1-GE3 MOSFET N-CH D-S 20V PPAK 1212-8
SIZ710DT-T1-GE3 MOSFET N-CH D-S 20V POWERPAIR
SIZ720DT-T1-GE3 MOSFET N-CH D-S 20V POWERPAIR
SIZ902DT-T1-GE3 MOSFET N-CH 30V DUAL D-S
SKY12322-86LF-EVB BOARD EVALUATION FOR SKY12322-86
相关代理商/技术参数
SIS472DN 制造商:VISHAY 制造商全称:Vishay Siliconix 功能描述:N-Channel 30 V (D-S) MOSFET
SIS472DN-T1-GE3 功能描述:MOSFET 30 Volts 20 Amps 28 Watts RoHS:否 制造商:STMicroelectronics 晶体管极性:N-Channel 汲极/源极击穿电压:650 V 闸/源击穿电压:25 V 漏极连续电流:130 A 电阻汲极/源极 RDS（导通）:0.014 Ohms 配置:Single 最大工作温度: 安装风格:Through Hole 封装 / 箱体:Max247 封装:Tube
SIS476DN 制造商:VISHAY 制造商全称:Vishay Siliconix 功能描述:N-Channel 30 V (D-S) MOSFET
SIS476DN-T1-GE3 功能描述:MOSFET 30V 2.5mOhm@10V 40A N-Ch G-IV RoHS:否 制造商:STMicroelectronics 晶体管极性:N-Channel 汲极/源极击穿电压:650 V 闸/源击穿电压:25 V 漏极连续电流:130 A 电阻汲极/源极 RDS（导通）:0.014 Ohms 配置:Single 最大工作温度: 安装风格:Through Hole 封装 / 箱体:Max247 封装:Tube
SIS478DN 制造商:VISHAY 制造商全称:Vishay Siliconix 功能描述:N-Channel 30 V (D-S) MOSFET
SIS478DN-T1-GE3 功能描述:MOSFET 30V 12A N-CH MOSFET RoHS:否 制造商:STMicroelectronics 晶体管极性:N-Channel 汲极/源极击穿电压:650 V 闸/源击穿电压:25 V 漏极连续电流:130 A 电阻汲极/源极 RDS（导通）:0.014 Ohms 配置:Single 最大工作温度: 安装风格:Through Hole 封装 / 箱体:Max247 封装:Tube
SIS488DN-T1-GE3 制造商:Vishay Semiconductors 功能描述:SINGLE N-CHANNEL 40V POWERPAK 1212-8 MOSFET 5.5MOHM@ 10V - Tape and Reel 制造商:Vishay Siliconix 功能描述:MOSFET N-CHAN 40V 1212-8
SIS5102QP1HT1G 功能描述:开关变换器、稳压器与控制器 MI HI SD SMRT HOTPLG RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel