Breaking News
Blog

Using MCUs: Intelligent Digital Power Outputs

NO RATINGS
View Comments: Newest First | Oldest First | Threaded View
Page 1 / 3   >   >>
antedeluvian
User Rank
Author
Re: smart PWM "mosfets"
antedeluvian   11/21/2013 9:42:26 AM
NO RATINGS
salbayeng

I've also looked at using the UC2845 (usually a current mode flyback PWM driver) driving any old mosfet. If you average the PWM signal (while it's running closed loop)   as an analog voltage , you can determine whether it is open or short circuit.

This is a great idea. You shoul;d submit it to EDN's Design Ideas- make yourself a few bucks.

 

Have you seen the DRV101

Thnaks for the pointer. I recently saw a TI part, but was only rated to 20V, for automotive applications. This one I can use!

salbayeng
User Rank
Author
smart PWM "mosfets"
salbayeng   11/21/2013 7:29:49 AM
NO RATINGS
Hi Aubrey , 

More good stuff in your blog as always.

Unfortunate that the only units with status indication, the ZXMS6002G and ZXMS6003G have a feeble 500mohm  Rds , what kind of automative load only uses 1A? , heck a simple PTC placed in close proximity to the MOSFET tab would provide sufficient protection for a 12v / 1A load.

Have you seen the DRV101 , in a TO220 5pin  package , meant for solenoid driver, hits it hard at first then throttles back to PWM, interestingly it has a fault output for both under and overcurrent. 

http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=drv101&fileType=pdf 

I've also looked at using the UC2845 (usually a current mode flyback PWM driver) driving any old mosfet. If you average the PWM signal (while it's running closed loop)   as an analog voltage , you can determine whether it is open or short circuit. But it won't go to 100% duty so only good for bulbs and coils / motors.

Underdriving the gate is a big MOSFET killer , so some kind of de-saturation detector would be helpful.

Brian@BDH
User Rank
Author
Re: Another approach to current monitor
Brian@BDH   9/11/2013 3:58:31 PM
NO RATINGS
 

@Aubrey: Re: Do you know if there is a data sheet available? Perhaps it is still preliminary.

Yes, the datasheet is in Max's inbox - I asked him to forward it to you since I didn't have your email address readily available :-) 

Correct, the part does not launch in production until Dec13/Jan14, so the datasheet is still a Target datasheet and the Final datasheet has not been released on the website yet.  However, samples are available!

 

Max The Magnificent
User Rank
Author
Re: Very much useful
Max The Magnificent   9/11/2013 1:28:50 PM
NO RATINGS
@Sanjib.A: Hi Max, Thanks a lot for sharing the guide.

It's my very great pleasure -- I think it contains a lot of useful information.

Sanjib.A
User Rank
Author
Re: Very much useful
Sanjib.A   9/11/2013 1:02:56 PM
NO RATINGS
Hi Max, Thanks a lot for sharing the guide. This is a pretty elaborated description about the calibration methodology and the advantages of the newer devices with advanced current sensing technique, which make the calibration easier. I am also impressed to see the option for "no calibration", where the "typical" slope and offset correction factors could be used from the datasheet instead of adding a calibration process during production...this is good for the application where accuracy is not that important. Thanks!

Max The Magnificent
User Rank
Author
Re: Very much useful
Max The Magnificent   9/11/2013 10:53:29 AM
NO RATINGS
@Sanjib.A: I will check out your & Max'x blogs.

I think Antedeluvian was referring to my comment where I mentioned Infineon's ADVANCED SENSE Calibration and Benefits guide (http://tinyurl.com/ADVANCED-SENSE-1-0)?

I would be very interested to hear your thoughts on this guide -- Max

Max The Magnificent
User Rank
Author
Re: Another approach to current monitor
Max The Magnificent   9/11/2013 10:50:47 AM
NO RATINGS
@Antedeluvian: Perhaps I should do a blog on current measurment?


Yes please :-)

antedeluvian
User Rank
Author
Re: Another approach to current monitor
antedeluvian   9/11/2013 9:16:24 AM
NO RATINGS
Brian

Infineon TLI4970 High-Precision Current Sensor

This looks a very interesting device. I only seem to find a product brief. Do you know if there is a data sheet available? Perhaps it is still preliminary. I did find a YouTube video, but not much else. There is also supposed to be an evaluation kit, but I can't find stock of it or the part anywhere.

Brian@BDH
User Rank
Author
Re: Another approach to current monitor
Brian@BDH   9/10/2013 11:42:27 PM
NO RATINGS
 

@antedeluvian: Re: Perhaps I should do a blog on current measurement?

You might like these devices when you need/want an integrated solution!

Infineon TLI4970 High-Precision Current Sensor

 

Sanjib.A
User Rank
Author
Re: Very much useful
Sanjib.A   9/10/2013 10:48:22 PM
NO RATINGS
True, I agree with you on that it better be calibrated along with the ADC as a system. One could use the ADCs often available built-in the modern microcontrollers. I will check out your & Max's blogs. Thanks for the information!

Page 1 / 3   >   >>
Most Recent Comments
michigan0
 
SteveHarris0
 
realjjj
 
SteveHarris0
 
SteveHarris0
 
VicVat
 
Les_Slater
 
SSDWEM
 
witeken
Most Recent Messages
9/25/2016
4:48:30 PM
michigan0 Sang Kim First, 28nm bulk is in volume manufacturing for several years by the major semiconductor companies but not 28nm FDSOI today yet. Why not? Simply because unlike 28nm bulk the LDD(Lightly Doped Drain) to minimize hot carrier generation can't be implemented in 28nm FDSOI. Furthermore, hot carrier reliability becomes worse with scaling, That is the major reason why 28nm FDSOI is not manufacturable today and will not be. Second, how can you suppress the leakage currents from such ultra short 7nm due to the short channel effects? How thin SOI thickness is required to prevent punch-through of un-dopped 7nm FDSOI? Possibly less than 4nm. Depositing such an ultra thin film less then 4nm filum uniformly and reliably over 12" wafers at the manufacturing line is extremely difficult or not even manufacturable. If not manufacturable, the 7nm FDSOI debate is over!Third, what happens when hot carriers are generated near the drain at normal operation of 7nm FDSOI? Electrons go to the positively biased drain with no harm but where the holes to go? The holes can't go to the substrate because of the thin BOX layer. Some holes may become trapped at the BOX layer causing Vt shift. However, the vast majority of holes drift through the the un-dopped SOI channel toward the N+Source,...

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed