Application Note Understanding Thermal Specifications of Bridge Rectifiers

时间： 2022-03-09 来源：Diotec

代理服务

技术支持

现货查询

批量订货

Mastering thermal management of power applications is one of the highly underestimated challenges electronic designers must overcome. This application note explains the mechanisms of heat transfer in semiconductor components along with DIOTEC's datasheet parameters of 1ph and 3ph Bridge Rectifier. It further describes a way to determine whether a bridge is suitable for a given output current and ambient respectively case temperature.The conduction of electric current at a voltage generates heat in a semiconductor material thus increasing the temperature of the pn-junction. A higher temperature is directly tied to an increased probability of failures and a reduced component lifetime. In order to assure safe operation, designers must take measures to reduce the junction temperature during operation.

Mechanisms of heat transfer in semiconductor components (free standing)

Figure 1 Heat Transfer Path when Free Standing

In semiconductor components, heat transfers from the hot areas to the cooler ones by different paths. Fig. 1 shows the thermal resistive path of heat transfer from the hot pn-junction to the ambient via the component case.

T_j= P * R(_{th j-a})+Ta (1)

R(_{th j-a})= R(_{th j-c})+R(_{th c-a})

T_j: Temperature of pn-junction

T_a: Temperature of ambient

P: Power Dissipation

R(_{th j-a}): Thermal Resistance junction-to-ambient

R(_{th j-c}): Thermal Resistance junction-to-case

R(_{th c-a}): Thermal Resistance case-to-ambient

2. Mechanisms of heat transfer in semiconductor components (on heatsink)

Figure 2 Heat Transfer Path with Cooling fin

A heatsink improves the heat transfer by introducing an additional path with a low thermal resistance.

T_j= P * R(_{th j-a})+Ta (2)

R(_{th j-a})= R(_{th j-c})+R(_{th c-cf})+R(_{th cf-a})

R(_{th c-cf}): Thermal Resistance case-to-cooling fin

R(_{th cf-a}): Thermal Resistance cooling fin-to-ambient

A thermal paste applied between the thermal pad of the component case and the cooling fin improves the heat transfer at the contact area. Recommendations of the thermal paste manufacturer must be respected and the thermal resistance of the paste must be taken into account.

3.1 Free standing

3. Datasheet Specifications of Bridge Rectifiers

For free standing bridge rectifiers, Diotec specifies a maximum average rectified current at a certain ambient temperature. This is sampled close to the component case (as specified in the datasheet footnotes). If the application requires a maximum ambient temperature higher than the datasheet specification, the max. current must be derated. For a reliable design, operation at maximum values is to be avoided with appropriate safety margins in place.

3.2 Cooling fin

When mounted on a heatsink (e.g. a cooling fin), the total thermal resistance between pn-junction and ambient is reduced. The larger the cooling fin area, the lower the thermal resistance and the better the thermal transfer. Diotec specifies a maximum average rectified current for a specific case temperature and area of the cooling fin.Due to the improved thermal resistance, the maximum value for the current is higher than for applications where the bridge rectifier is free standing.

3.3 Forced cooling

For applications without a heatsink, an active cooling (e.g. cooling fan) can be used to improve heat transfer.

4. Estimation of junction temperature at given output current

Formulas (1) and (2) allow to determine the junction temperature at given ambient respectively case temperature, when power losses P are known. No matter if single or three phase bridge, always only two diodes are conducting at the same time.

Depending on how Rth is defined, this has to be considered accordingly. The duty

cycle per diode is 1/2 for the single phase bridge and 1/3 for the three phase one.

Power dissipation P becomes then as follows:

P = V_F * I_FAV * n * m

V_F: Forward voltage drop of the single diode at I_FAV and T_j

I_FAV: Average current at the output of the bridge

n= 1/2 (for 1ph bridges) or n= 1/3 (for 3ph bridges)

m= 2 (if _Rth is „per device“) or m= 1 (if _Rth is „per diode“)

Since VF is difficult to be measured in the real application, one can use the maximum value at 25°C as specified in the data sheet. Since real diodes will get hot during operation and VF thus will get down (due to its negative temperature coefficient), this procedure leads automatically to a certain safety margin. As such it covers unforeseeable, short overloads which might occur in the application.

It is a good practice to use the bridge at junction temperatures of not much higher than 100°C, even if maximum rating is at 150°C. According to Arrhenius‘ law, every 10K of reduced T_j improves the lifetime by a factor of 2. So in order to achieve a long lifetime and high reliability, it is worth to spend some effort in improved cooling or to choose a higher rated device.

发送到邮箱 |
+1 赞 0
收藏
评论 0
| 转发至：

本文由电子人生转载自Diotec，原文标题为:Application Note Understanding Thermal Specifications of Bridge Rectifiers，本站所有转载文章系出于传递更多信息之目的，且明确注明来源，不希望被转载的媒体或个人可与我们联系，我们将立即进行删除处理。

全部评论（0）

暂无评论

三相桥式整流器DB35-16用于风力发电机蓄电池充电，具有1600V的VRRM和35A的IFAV

通过风能实现更多的独立。然而，由于风能并不总是可用的，风能存储系统稳定了风能的可用性。多余的能量被储存起来供以后使用。DIOTEC的DB35-16桥式整流器，具有高达1600V的VRRM和高达35A的IFAV的三相整流器，它们被安装在涡轮机的头部，作为电池充电器的输入级储存能量。每个容器容量高达1.1MWh的强大电池存储系统，用于提高效率的无变压器逆变器、电动汽车电池模块以及汽车行业电池模块。

2024-03-23 - 应用方案代理服务技术支持现货查询批量订货

桑德斯（SMC）桥式整流器选型指南

目录- Bridge Rectifiers

型号- GBU1006,UG4KB10,UG4KB100,GBU1004,GBU1002,MB10S,GBU1001,KBP2005G,MB6F,MB10F,DF156,DF157,DF154,DF155,MB6S,DF152,DF151S,DF153,DF151,GBPC3510,DF07,DF06,FTB2F-15,DF05,DF04,DF03,DB107S,DF02,GBU4005,DF01,SM2S,RMB6S,GBU408G,DB151S,UG4KB20,FTB4F-15,DF150S,ABS8,KBP204G,ABS6,DF158S,SM1S,ABS4,ABS2,MB8F,ABS10,DF1510S,GBJ25005,FTB6F-15F,MB8S,GBJ2510,DB105S,FTB6F-15,DB157S,SM4S,MB05S,GBU1010,GBU406G,UG4KB40,GBU410G,GBJ2502,GBJ2504,GBPC35005,GBJ2501,MB05F,DB106S,DF156S,KBP206G,FTB8F-15,GBJ2506,KBP210G,GBJ2508,GBU1008,GBU4005G,DB154S,GBPC2508,FTB4F-15F,FTB10F-15,GBPC2501,GBPC2502,MB2F,GBPC2506,GBPC2504,SM6S,MB2S,FTB1F-15,DB103S,DB155S,FTB10F-15F,GBU404G,MB1F,GBPC2510,UG4KB60,RMB2S,KBP208G,MB1S,DB156S,DB104S,DF154S,FTB1F-15F,GBU10005,DB152S,MB4F,GBU410,GBU401G,SM10S,GBU406,GBU408,SM8S,MB4S,DB101S,KBP201G,DB153S,RMB4S,SM05S,GBPC3508,FTB8F-15F,UG4KB05,GBPC3502,UG4KB80,GBU401,FTB2F-15F,GBPC3501,GBU402G,GBPC25005,GBPC3506,GBU402,GBPC3504,GBU404,DB102S,DF152S,KBP202G

2016/3/2 - SMC - 选型指南代理服务技术支持现货查询批量订货

PANJIT Introduces GBJA and KBJB Low Profile Packages for Bridge Rectifiers

PANJIT Introduces Latest GBJA and KBJB Low Profile Packages for Bridge Rectifiers. This substantial reduction in body height makes these bridge rectifiers ideal for applications where space is at a premium, responding to the increasing demand for compact and efficient power solutions.

2024-06-28 - 产品代理服务技术支持现货查询批量订货

DISCRETE SOLUTIONS FOR EV CHARGING

型号- UGB8JT,BYG23T,LDI1117 SERIES,DBI25-08A,DBI25-18A,DI012N60D1,DIJ020N60,ESD9BL0522P,DBI20-16B,TGL200CF08,AM2000,BYG10M,SMS560-3G,DBI20-08B,BYG10K,DI6206 SERIES,FR2YSMA,DI79L SERIES,1.5SMC550CA,ESD5Z3V3,ESD9BL24P,ESD5Z3V12,P6SMB400CA,SK34SMA-3G,UFT800J,P6SMB550CA,1.5SMC400CA,MUR860,MURF2060CT,P2500Y,P2500T,DI78L SERIES,DI78M SERIES

10/2020 - DIOTEC - 商品及供应商介绍 - Version 10/2020 代理服务技术支持现货查询批量订货

Diotec（德欧泰克）整流桥选型指南

目录- Bridge Rectifiers

型号- GBU10J,KBPC2506FP,DB15-08,GBU10K,DB15-06,MB10S,GBU10M,KBPC5004FP,KBPC1514WP,S40,KBPC810,DBI20-16B,KBPC3502WP,GBU10B,KBPC2510WP,GBU10A,GBU10D,KBPC1502FP,DB15-04,DB15-01,DB15-02,B125S2A,B500C5000-3300,DB15-16,KBPC3501FP,B380C7000-4000,B500C2300-1500B,KBPC1006WP,B500C2300-1500A,GBI25M,KBPC2506WP,S40F,B40FS,KBPC3501I,GBI25J,GBI25K,ABS8,KBP204G,DB15-10,ABS6,GBI25G,ABS4,GBI25A,KBPC1514FP,DB15-14,GBI25B,ABS2,DB15-12,GBI25D,ABS10,CS10D,KBPC1016WP,KBPC3514FP,B40S15A,B380C2300-1500B,B380C2300-1500A,KBPC3510I,KBPC1004FP,B125S,KBP302G,B125R,KBPC2516FP,KBPC3502FP,KBPC604,B125D,KBPC606,GBI10M,KBPC1504WP,KBPC608,GBI35M,CS10S,KBPC601,KBPC600,GBI35J,B125C3700-2200,GBI35K,KBPC602,GBI35D,KBPC1016FP,KBPC3514WP,KBP206G,GBI35G,B40C3700-2200,GBI35A,GBI35B,B250C3700-2200,CS20D,KBPC5006FP,B40C7000-4000,MYS40,B500R,KBPC2504FP,B250C2300-1500A,S80,B250C2300-1500B,B500D,DB25-10,DB25-12,KBPC1512WP,DB25-14,DBI20-12B,B80S15A,GBI10J,KBPC3504I,DB25-16,GBI10K,MYS380,MB2S,GBI10G,KBPC2516WP,B250S2A,GBI10A,GBI10B,KBPC3504WP,GBI10D,KBPC1004WP,S380F,KBPC2510I,GBI20M,DB25-01,B80C5000-3300,DB25-02,KBPC1501WP,DB25-04,DB25-06,CS20S,DB25-08,KBPC2504WP,MYS250,KBPC5010FP,B80FS,KBPC1512FP,KBPC2501I,CS30D,KBPC1014WP,S250F,B40FD,B80R,B80S,KBPC3516FP,GBI20J,GBI20K,KBPC3502I,GBI20D,B80D,KBPC1002FP,MB4S,GBI20G,B80C7000-4000,S250K,GBI20A,GBI20B,MYS125,KBP310G,KBPC1501FP,GBU4A,KBPC2514FP,KBPC802,KBPC3504FP,GBU4G,KBPC804,B40C5000-3300,GBU4D,KBPC806,KBPC1502WP,B380FD,GBU4B,KBPC808,CS30S,GBU4M,B250S15A,GBU4K,KBPC801,KBPC1014FP,GBU4J,KBPC800,B500S,KBPC3516WP,KBP202G,B380FS,KBPC1510WP,DB35-12,KBPC5008FP,DB35-10,KBPC2502FP,B80C3700-2200,B500S2A,CS40D,MB6S,GBV15B,KBPC1001FP,GBV15D,KBPC2514WP,KBP308G,KBPC1506FP,GBV15G,GBV15J,KBPC3506WP,KBPC3508I,GBV15K,DB35-16,S380,GBV15M,DB35-14,KBPC2502I,DB35-02,GBI40W,GBU6B,DB35-01,GBU6A,B80S2A,KBPC1002WP,KBPC5012FP,S125,GBU6K,B380C3700-2200,GBU6J,GBI40J,GBU6G,GBI40K,GBI40M,GBU6D,B380S,KBPC1510FP,CS40S,B380R,KBPC2502WP,DBI25-12A,B500S15A,GBU6M,MYS80,DB35-08,S250,DB35-06,S80F,DB35-04,KBPC1012WP,KBPC2501FP,KBPC3510FP,KBPC5001FP,B80FD,B500C7000-4000,DBI25-16A,PB1010,CS50D,B250S,GBI40G,B125C2300-1500B,MB8S,B125C2300-1500A,GBI40D,KBPC1008FP,B250R,KBPC3506I,B250D,GBS4B,B250C7000-4000,GBU8D,GBS4A,KBPC2504I,KBPC1001WP,GBU8B,KBPC2512FP,GBU8A,PB1008,KBPC1508FP,B125C7000-4000,GBS4K,KBPC1508WP,GBU8M,GBS4J,PB1004,GBU8K,GBU8J,PB1006,GBS4G,KBPC3506FP,PB1000,GBU8G,PB1001,GBS4D,GBU100G,PB1002,GBUK8G,KBPC1012FP,KBPC3510WP,GBS4M,B40S2A,KBPC2501WP,KBP210G,CS50S,KBPC2508FP,KBPC5002FP,B500C3700-2200,KBPC1516WP,GBUK8D,DBI25-18A,ABS15Y,KBPC610,B250C5000-3300,B380S15A,B125FS,B125FD,KBP304G,KBPC1504FP,KBPC2512WP,DBI20-08B,KBPC3508WP,B125S15A,B40C2300-1500,B380C5000-3300,B250FS,ABS15G,ABS15M,ABS15K,ABS15J,KBPC1008WP,KBPC2506I,ABS15S,B80C2300-1500A,B80C2300-1500B,B250FD,KBPC2508WP,KBP208G,KBPC1516FP,ABS15D,B40C2300-1500B,KBPC1010WP,B380D,GBU12K,S125K,GBU12M,KBPC3512FP,B40R,B40S,S125F,DBI25-08A,KBP306G,KBPC3501WP,GBU12B,B380S2A,GBU12A,B40D,GBU12D,KBPC1006FP,GBU12G,GBU12J,GBI15A,S500,KBPC1506WP,KBPC2510FP,KBPC3508FP,KBPC2508I,B125C5000-3300,KBPC1010FP,GBI15J,GBI15K,GBI15M,KBPC3512WP,GBI15G,GBI15B,GBI15D

2021 - DIOTEC - 选型指南 - Version 26 代理服务技术支持现货查询批量订货

利用绿色能源生产，采用无卤素成型复合材料的GBU10K-LV，为整个城市节约电力

像美国或欧盟的“能源之星”这样的指令要求减少电力消耗，特别是在运行24/7的ICT电源上。DIOTEC的GBU10K-LV桥式整流二极管芯片的正向压降比标准GBU10K版本低10%。由于每半个周期始终有两个二极管导通，这导致整体节能20%。尽管单个数据服务器的节能可能不多，但人们必须考虑到全球范围内运行的大量此类设备。

2024-05-11 - 应用方案代理服务技术支持现货查询批量订货

Diotec Rectifier Bridge GBI25J-LV Offers 10% Lower Forward Voltage Drop to Energy Saving Power Supply of Data Servers

The input bridge GBI25J-LV by Diotec is built with rectifier chips offering a 10% lower forward voltage drop than the standard version GBI25J. Since always two diodes are conducting per main cycle, the power savings are even 20%. This is a lot for a power supply running 24/7.

2024-04-04 - 应用方案代理服务技术支持现货查询批量订货

PANJIT‘s New Ultra-Low VF Bridge Rectifier Series: Optimizing Power Efficiency and Reliability Across Various Applications

PANJIT proudly introduces its latest Ultra-Low VF Bridge Rectifier Series. Engineered with oxide planar chip junction technology and featuring PI protection layers, this series is poised to redefine the standards of power efficiency and reliability across various applications.

2023-10-28 - 产品代理服务技术支持现货查询批量订货

Smart Garage Door Opener Drive Supplied by Energy Saving Bridge GBI25J-LXN

For GBI25J-LXN, the typical forward voltage drop of the four rectifier diodes is 0.90 V, saving energy during standby operation. Repetitive peak forward current can reach up to 60 A, powerful enough at any time when the motor starts to pull the door.

2024-03-31 - 应用方案代理服务技术支持现货查询批量订货

Diotec Products for Power LED Lamps – Halogen and CFL Retrofits Application Note

型号- GU5.3,TGL200F10,CS20S,SGL1-40,S500,SK34SMA,GU10,S250,SK14,MR16

2011-02-02 - DIOTEC - 应用笔记或设计指南代理服务技术支持现货查询批量订货

Forward surge current limit of GBU4 to GBU8 adjusted to industry standard Product Change Notification

型号- GBU4A,GBU6B,GBU8D,GBU6A,GBU8B,GBU8A,GBU6K,GBU8M,GBU6J,GBU4G,GBU8K,GBU8J,GBU6G,GBU4D,GBU8G,GBU4B,GBU6D,GBU4M,GBU4K,GBU6M,GBU4J,GBU4,GBU6,GBU8

31.01.2013 - DIOTEC - 产品变更通知及停产信息代理服务技术支持现货查询批量订货

PSW5012 | PSW5018 Standard Recovery Rectifier Diodes

型号- PSW5018,PSW5012

2024/2/22 - DIOTEC - 数据手册 - Version 2022-08-15 代理服务技术支持现货查询批量订货

Powerful AC to DC Rectification on Printed Circuit Boards

The GBU10A, GBU10B, GBU10D, GBU10G, GBU10J, GBU10K, GBU10M series of single phase bridge rectifiers from Diotec are offered in the GBU package with 5.08mm pitch. The devices can be operated free-standing for up to 7.0A of output current as well as clipped onto a heatsink for up to 10A. They are ideally suited for printed circuit board assemblies. With a case length of 21.5mm and a thickness of 3.4mm it can be used even in tight assemblies where space is restricted.