NexFET™ Power MOSFETs

Forum Post: RE: CSD17552Q3A footprint and layout

Brett Barr1 — Wed, 15 May 2013 21:21:00 GMT

Aaron,

Got the following response from our packaging department:

"We can give ACAD DXF files, not allegro or mentor. They can import that and convert to their workable software"

I've attached the appropriate file. Hope this is sufficient.

(Please visit the site to view this file)

Forum Post: RE: CSD18532Q5B Rise & Fall Time

Brett Barr1 — Tue, 14 May 2013 16:00:00 GMT

Niyant,

Your results make sense with what we would think.

I would not expect a great discrepancy between tr and tf because you have two factors that basically cancel each other out. On the one hand, driving the voltage at 5V, the rise time is depended on charging the gate to Qg(5V) = 27nC as opposed to Qg(10V)=52nC. However, because your voltage has halved but your gate resistance has stayed the same, your current is going to be about half. Thus you are building up roughly half the charge with roughly half the current. The same argument could be made for discharge.

On and off delay times are a function of the threshold voltage (and therefore threshold charge). When charging up, it takes roughly the same amount of time to hit this limit and induce device turn on. An increase in on delay time can be explained by the decrease in gate drive current due again, to the halving of Vgs. However, when at 5V, because you are much closer to the device threshold, it will take much less time for device to hit threshold on the way back down, which explains the dramatic decrease in turn off delay time from 10Vgs to 5Vgs.

Forum Post: RE: Material used for MOSFET / diode encapsulation

Brett Barr1 — Fri, 03 May 2013 21:20:00 GMT

Hello.

FETs are contained in a plastic compound mold.

However, all information necessary for thermal simulation should be provided in the FET datasheet.

Forum Post: RE: P-Channel 4 terminal Mosfet with Body

Sujan Manohar — Wed, 01 May 2013 03:21:00 GMT

Hello Brett

Thank you so much for double checking on my behalf. In case you come across any other power P-MOSFET, kindly let me know.

Thanks

Sujan

Forum Post: RE: Switching Mosfet Dissipation

Brett Barr1 — Fri, 12 Apr 2013 20:21:00 GMT

Multiplying average Vds by average Ids will not necessarily yield an accurate power dissipated value. Consider that when the FET is off, Vds is high and Ids is virtually zero. When the FET is on, Ids is high and Vds is virtually zero.

A more accurate method for measuring power dissipated is to use P=I^2*R. Thus you want to square you average Ids(on) through the FET and multiply this by the typical on resistance of the FET. If you want to be conservative, you can multiply by the max resistance of the FET, at your given Vgs, and then multiply this by the temperature coefficient for the temperature you are running at. Finally, multiply this value by your duty cycle to get the power dissipated by the FET.

Pdiss = (Duty Cycle) * (Ids(on) average)^2 * (Rds(on) @ Gate Voltage you are driving at) *(Normalized Temperature Coefficient @ the temp you are running at)

All of these parameters should be available within the datasheet. Make sense?

Forum Post: RE: CSD87350Q5D Ron Parameter

Brett Barr1 — Wed, 13 Mar 2013 14:46:00 GMT

In the case where current limiting is calculated, Rdson should be used. Zdson should only be used in comparing power losses with discrete devices. Let me know if you have any further questions or need some more information.

Forum Post: RE: CSD25401Q3 PCB Trace Widths

Brett Barr1 — Mon, 18 Feb 2013 22:19:00 GMT

General strategy is to use 20 mil trace width for the gate pin and copper pour for the drain and source terminals.

Forum Post: RE: CSD25401Q3 PCB Pattern

Brett Barr1 — Wed, 13 Feb 2013 15:24:00 GMT

Steven,

The pattern on the left is the recommended PCB land pattern. The pattern on the right is supposed to be the recommended stencil pattern, but it is incorrect (its actually a device footprint). Thank you for bringing this to our attention - turns out we need to update this datasheet. But to answer your question, you do not need wings.

We'll work on getting these datasheets corrected but it may take some time to matriculate through the system. In the mean time, please let me know if there is anything else I can assist you with.

Forum Post: RE: Power Dissipation for MOSFET CSD17303Q5

Brett Barr1 — Wed, 13 Feb 2013 14:56:00 GMT

Yes Sudha, your understanding is correct.

Switching frequency is the frequency you are driving the power block at. It is a choice determined by your design and the limitations of the power block and driver IC that you will be using this device in conjunction with.

Forum Post: RE: CSD17313 wrong dimension for PCB Pattern

Brett Barr1 — Tue, 15 Jan 2013 20:03:00 GMT

I've been told the datasheet should update overnight tonight on TI's website. Here's the final version.

Forum Post: RE: Measured RDs(ON) is greater than that specified in datasheet

Arjun_Prakash — Wed, 19 Dec 2012 20:46:00 GMT

RDSon test is one of the parameters that requires a very clean test setup.

For RDSon you need a differential source FORCEHI/SENSEHI connected to the DRAIN and you need a FORCELO/SENSELO connected to the SOURCE. The current flowing between the FORCEHI/FORCELO should be 10A. The SENSEHI/SENSELO should be connected at the DUT.

For 10A the Voltage between Drain and Source will be 15mV (1.5mOhm). You need a high impedance measurement instrument connected between SENSEHI/SENSELO. You can use something like INA128 with a gain of 100 so that the 15mV is gained up to 1.5V and you can use a DMM to verify your RDSon.

Forum Post: RE: Gate driver needed for IGBT

John Stevens — Fri, 07 Dec 2012 20:36:00 GMT

Take a look at UCC27531. This is specifically an IGBT gate driver. Good luck!

John

Forum Post: RE: What is the most appropiate MOSFET (SW1,SW2,SW3,SW4) for this application?

Brett Barr1 — Mon, 03 Dec 2012 16:36:00 GMT

Looks like you'll need to use 150V MOSFETs for this application. Unless you are anticipating seeing much ringing in which case you may need up to 200V FETs. Unfortunately, TI currently has no plans to offer anything greater than 100V. Thanks for posting and let me know if you have any further questions.

Forum Post: RE: recommend on MOSFET

golan kormian — Tue, 27 Nov 2012 07:55:00 GMT

Hi,

this part of application will work only when there is no power at the mains (no electricity....) and the battery will feed the board.

meanwhile i found the tps22965, MOSFET with control on/off pin - what do u think?

u may reccomend on other MOSFET part.

can u send a reference design for the control circuit at the MOSFET?

Forum Post: RE: CSD25302 and CSD16301 resistance while damaged

Brett Barr1 — Mon, 26 Nov 2012 14:43:00 GMT

Rachel,

Sorry for the delayed response. Things were a little hectic here leading up to Thanksgiving.

Talking to the team, here they aren't sure exactly what failure information you are looking for. If the FET is operating in the 5-10 ohm range, that means the FET is being driven very low, close to the threshold. Even at the minimum of 3 amps and 5 ohms, that is still 15W of power, far above the maximum power dissipation of the device. The FET will not be able to handle anything close to this. What type of failure information are you looking for exactly? Feel free to contact me directly and maybe I can be of more assistance. Thanks,

Brett

Forum Post: RE: IGBT 75 A switching

Brett Barr1 — Thu, 15 Nov 2012 14:28:00 GMT

Unfortunately, TI does not offer any IGBT's at this time, with no plans to do so in the foreseeable future.

Forum Post: RE: CREATING POWER MODULES FROM DISCREAT MOSFET ARE IGBT'S

WILLIE MCCAIN — Wed, 07 Nov 2012 17:38:00 GMT

PART NUMBERS

P/N AOB14N50

P/N AOB29S50

SEE HOW MANY PCS FOR EACH PART

SWITCHING IN A BOOST POWER SUPPLY APPLICATION AT 22KHZ MIN TO 200 KHZ MAX

V OUT OF BOOST 300 VDC CONSTANT

MY EMAIL WLMCCAIN@COMCAST.NET / PHONE 561-853-4160 CALL ANYTIME

THANKS SO MUCH

WILLIE L. MCCAIN

Forum Post: RE: High Voltage, Low Current H Bridge Design

Brett Barr1 — Fri, 02 Nov 2012 20:45:00 GMT

Ok, sorry for the delayed response. So talking it over with our engineers, they would recommend you use 150V rated FETs (N-Channel or P-Channel) for your H-Bridge. Unfortunately we do not offer this product and have no plans on doing so in the near future. Thank you, and let me know if there is anything else I can do to assist you with your design.

Brett Barr

Forum Post: RE: H bridge driver

Brett Barr1 — Wed, 17 Oct 2012 13:39:00 GMT

Either the CSD18531Q5A or the CSD18533Q5A will do the job. Both will be perfectly capably handling your power requirements, however the18531 has a slightly lower Rdson value. Please let me know if more help is required. Thanks for posting,

Brett Barr

Forum Post: RE: Need help finding TI transistors A7611, & A7617

Brett Barr1 — Wed, 29 Aug 2012 20:37:00 GMT

Ron,

We do not carry those parts nor could I find any sign of them in our inventory. Any information that you could provide regarding what kind of voltage they would need to withstand, or a circuit schematic would be very helpful for finding an equivalent FET.