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Electronics => Projects, Designs, and Technical Stuff => Topic started by: halexa on June 28, 2016, 06:21:51 am

Title: Power calculation 4chanel HSD driver
Post by: halexa on June 28, 2016, 06:21:51 am

Hi,

How do you calculate total power of a 4 channel HSD driver?

Example: Each channel loads 1A and each channel have 140m? RDSon

Ch1: 1A*1A*0.14? = 0.14W
Ch2: 1A*1A*0.14? = 0.14W
Ch3: 1A*1A*0.14? = 0.14W
Ch4: 1A*1A*0.14? = 0.14W

tot: 4*0.14W = 0.56W

OR

tot: 4A*4A*0.14? = 2.24W

Title: Re: Power calculation 4chanel HSD driver
Post by: tszaboo on June 28, 2016, 08:29:58 am

Quote

HSD may refer to:
School districts[edit]
Hackett School District, in Arkansas, United States
Harrison School District (disambiguation)
Hazelwood School District, in Missouri, United States
Hillsboro School District in Oregon, United States
Other uses[edit]
Hamstead railway station, England
Hardanger Sunnhordlandske Dampskipsselskap, a Norwegian transport company
Heliophysics Science Division, a branch of the United States National Atmospheric and Space Administration
High School Diploma
Historical Society of Delaware
Hollywood Stunt Driver, a live show at Warner Bros. Movie World
Homeland Security Department
Hybrid Synergy Drive, a set of hybrid car technologies
Hydroxysteroid dehydrogenase
Hypoactive sexual desire, a disorder characterized as a lack or absence of sexual fantasies and desire for sexual activity
Tukey's honest significant difference test

Sorry, does not compute.

Title: Re: Power calculation 4chanel HSD driver
Post by: halexa on June 28, 2016, 10:45:25 am

Hi,

Sorry for not being clear:

HSD  = High side driver

Example:
http://www.st.com/content/ccc/resource/technical/document/datasheet/cd/1f/d3/43/b8/2d/48/0b/DM00157127.pdf/files/DM00157127.pdf/jcr:content/translations/en.DM00157127.pdf (http://www.st.com/content/ccc/resource/technical/document/datasheet/cd/1f/d3/43/b8/2d/48/0b/DM00157127.pdf/files/DM00157127.pdf/jcr:content/translations/en.DM00157127.pdf)

Title: Re: Power calculation 4chanel HSD driver
Post by: Rerouter on June 28, 2016, 10:49:04 am

The first unless your using them in parrellel, in which case your equivilent resistance would be 140/4, or 35 milli ohm,

Title: Re: Power calculation 4chanel HSD driver
Post by: samnmax on June 28, 2016, 10:54:38 am

The datasheet specifies 140mOhm RDSon per channel, so it should be 4*0.14W = 0.56W

However, take into account that the given RDSon is at 25°C, it is 280mOhm at 150°C, so you should probably take a more conservative number depending on the temperature reached on your application.

Title: Re: Power calculation 4chanel HSD driver
Post by: tszaboo on June 28, 2016, 11:48:10 am

As they said. I would calculate with worst case Rds and 1.5x nominal current. This package will be good with some 2W of dissipation if you have a ground plane and enough space to dissipate it.

Title: Re: Power calculation 4chanel HSD driver
Post by: halexa on June 28, 2016, 12:10:19 pm

Hi,

Thx for all the good advices.