VNH5019驱动能力评估

嗨霍勒斯，
H-Bridge的热性能取决于几个因素：负载曲线，初始温度，电源电压，PWM频率，PCB布局。 VNH5019AY热性能在第3章的数据表中有所描述。
 
这是一个如何做的例子
计算基于的热分析
您的要求：ILoad = 10A连续.VNH5019AY将管理的功率是，（固定最大RDSonHS = 0.0265Ohm，Max RDSonLS = 0.0265Ohm）：
 
PHS = RDSonHS * ILoad * ILoad = 2.65W;
PLS = RDSonLS * ILoad * ILoad = 1.15W;
 
假设一个具有16 cm2 Cu散热片区域的pcb（参见数据表中的图18 @ page26）：
RTH_HS = 26A°C / W; RTH_LS = 31°C / W; RTH_HL = 18°C / W; RTH_LL = 15A°C / W。
 
这将导致Delta Tj：
DTjH =
 小灵通*
 RTH_HS + PLS *
 RTH_HL =89.6°C。;
DTjL =
 PLS *
 RTH_LS + PLS *
 RTH_HL =83.35°C。;
 
从Tamb = 25°C最大Tj开始将是114.6°C，即热保护值（最小150°C）。
 
可以从不同的环境温度，负载曲线，PWM开关频率，PCB布局开始执行该考虑。
 
如果您想进行不同条件下的进一步分析，我建议您下载TwisterSIM：一个独特的电热模拟器，通过复杂的工程评估帮助缩短设计解决方案周期。
TwisterSIM免费提供
http://www.st.com/twistersim%20and%20include%20all%20M05
 它包括所有VIPower™¢M0-5＆amp;的热模型。 M0-7 H桥系列。
感谢致敬，
莱昂纳多



以下为原文





Hi Horace,
Thermal performance for H-Bridge depends on several factor: Load profile, initial temperature, supply Voltage, PWM frequency, pcb layout. VNH5019AY Thermal Performance  is described in the Datasheet, Chapter 3.

Here is an example on how to
calculate thermal analysis  based on
your request: ILoad=10A continuous.The power that VNH5019AY will manage is, (fixing max RDSonHS=0.0265Ohm, Max RDSonLS=0.0265Ohm):

PHS= RDSonHS * ILoad * ILoad = 2.65W;
PLS= RDSonLS * ILoad * ILoad = 1.15W;

Assuming a pcb with 16 cm2 Cu heat sink area (refer to fig18 @ page26 in the Datasheet):
RTH_HS=26°C/W; RTH_LS=31°C/W ; RTH_HL=18°C/W ; RTH_LL=15°C/W.


It will lead to a Delta Tj:

DTjH=
PHS*
RTH_HS+ PLS*
RTH_HL=89.6°C;

DTjL=
PLS*
RTH_LS+ PLS*
RTH_HL=83.35°C;



Starting from a Tamb=25°C max Tj will be 114.6°C, that is under thermal protection value (min 150°C).


This consideration can be performed starting from different ambient temperature, load profile, PWM switching frequency, pcb layout.



If you want to perform further analysis with different condition, I suggest you to download TwisterSIM: a unique electro-thermal simulator that helps shorten the design solution cycle by enabling complex engineering evaluations.

TwisterSIM is available for free at
http://www.st.com/twistersim%20and%20include%20all%20M05
  it include thermal model for all VIPowerâ„¢ M0-5 & M0-7 H-bridge family.
Thanks and Regards,
Leonardo

你好莱昂纳多，
真的谢谢你的回复。
16平方厘米的散热片真的很大。在实际设计中它应该没有那么多。在你的计算中，它不能在85℃的工作温度下工作。但我不得不说，你的计算过程与表17第27页略有不同。
下图是一个循环中的负载工作电流曲线。
一个周期中的总工作时间约为7毫秒。峰值电流@ 8~9A。 PWM频率为10Khz。
CHIP1，CHIP2，CHIP3的PCB散热片总厚度为4CM ^ 2.您能否进行更详细的分析？
顺便说一下，瞬态热分析非常困难。你有一个好方法吗？



以下为原文




hello  leonardo,
Really thanks for your reply.

16 cm^2 heat sink is really big. it should be not that much in actual design.Per your calculation,it can't work in 85C operation temperature.but I have to say,your calculation process is a little difference with Table 17 page27.

following picture is load work current curve in a cycle.

the total work time in a cycle  is about 7ms. peak current @8~9A. PWM frequency is 10Khz.
total PCB heat sink for CHIP1,CHIP2,CHIP3 is 4CM^2  .could you give a more detail analysis?
by the way,the transient thermal analyis is really tough. could you have a good method?

嗨leonardo，
我想用它来控制外部NMOSFET，以实现整个负载的反向反接
负载包括其他HSD和全桥驱动器。
这利用VNH5019本身提供电荷泵功能，
是否只有VNH5019才能实现所有负载反向同步保护？
期待你的回复



以下为原文




hi leonardo,
I want to use it to control external NMOSFET for anti reversal connection for the whole load
the load including other HSD and full bridge driver.
this make use of VNH5019 itself provide charge pump function,
is it possible with only VNH5019 to realize all loads anti reverse conncetion protection?
looking forward  to your reply

嗨霍勒斯，
对于详细的热模拟我的建议是使用
TwisterSIM免费提供
/external-link.jspa?url=http%3A%2F%2Fwww.st.com%2Ftwistersim%2520and%2520include%2520all%2520M05
 。
 它具有图形界面，是执行精确热模拟的简便方法，尤其是在瞬态条件下。
例如，我执行了您请求的案例：VNH5019，Load = 9A，
邮寄地址：PWM @ 10KHz的
 （50％DC）7ms周期Tamb = 85°C。这里附有相关情节：
正如您所看到的，驱动此负载没有问题。
关于你的要求
使用内部电荷泵
 驱动NMOSFET用于整个负载的反向反接：
在电池反接情况下没有问题。直接连接是可能的，但必须正确确定NMOSET的尺寸，以便为整个负载（VNH5019 +其他HSD +全桥驱动器）@max负载条件驱动电流。
感谢您对VI Power H-Bridge系列和最佳问候的关注，
莱昂纳多
 
 注意：原始帖子包含大量线程对话，只能迁移到第9级



以下为原文




Hi Horace,
For  detailed thermal simulation my suggestion is to use the
TwisterSIM available for free at
/external-link.jspa?url=http%3A%2F%2Fwww.st.com%2Ftwistersim%2520and%2520include%2520all%2520M05
  .
It has a graphical  interface and it's a easy way to perform accurate thermal simulation especially in transient condition.

For example I performed the case you requested: VNH5019 with a Load=9A,
mailto:PWM@10KHz
(50% DC)  7ms cycle Tamb=85°C. Here attached the  related plot:
As you can see no issue to drive this load.

Regarding your request
using internal charge pump
to drive NMOSFET for anti reversal connection for the whole load :
In reverse battery condition there is no issue. In direct connection it is  possible but it is mandatory to  proper dimension the  NMOSET able to drive the current for the whole load (VNH5019+ other HSD + full bridge driver ) @ max load condition.

Thanks for your interest in VI Power H-Bridge family and Best Regards,

Leonardo

Note: the original post contained a large number of threaded conversations and was only able to be migrated to the 9th level

抱歉，我无法获得分析工具，您能否帮助检查一下它是否可用？



以下为原文




sorry, I can't get the analysis tool,could you help check if it is available now?