NexFET™ Power MOSFETs Forum - Recent Threads

CSD17552Q3A footprint and layout

Aaron Spaete — Wed, 15 May 2013 19:42:55 GMT

Team,

My customer has run into the following issue:

"The template/tools I am using is not generating the footprint per the datasheet. Can you find out if there is a file for either Mentor LP Wizard or an Allegro .dra file that one of the engineers has generated already. I have a footprint that I can make some changes to and possibly get it to work."

Thanks,

Aaron

CSD18532Q5B Rise & Fall Time

Niyant Patel — Fri, 10 May 2013 15:50:59 GMT

What is the best method to approximate the rise and fall time of CSD18532Q5B with Vgs=5V (or 4.5V is this is readily available)?

Datasheet provides these values for Vgs=10V, Vds=30V, Ids=25A. not for Vgs=5V (or 4.5V). Ideally I would like an approximate formula to compute these values to include in an analytic model of the converter however a fixed value would suffice for initial calculations.

Similarly if Td(on) and Td(off) are impacted for Vgs=5V (or 4.5V) compared to datasheet values at Vgs=10V please provide approximate values.

Material used for MOSFET / diode encapsulation

krishnaraj kalghatgi — Fri, 03 May 2013 12:09:25 GMT

Hi. i want information about the material used for encapsulating the electronic components like MOSFET , diodes , IC ?

i need this information for thermal simulation '

please provide at the earliest

P-Channel 4 terminal Mosfet with Body

Sujan Manohar — Thu, 25 Apr 2013 20:54:36 GMT

Hello Sir/Madam

I am looking for four terminal P-MOSFET with body terminal. In my application i need to adaptively bias the body based on S/D , whichever is higher. Could you please point me to high voltage four terminal P-MOSFETS.

Voltage ratings specification ( if not available for this specification, any 4 TERMINAL power MOSFET with lower ratings is also fine):

-Used as load side switch in Boost converter.

- Max source voltage 30V

- Max drain voltage 30-40V

-Max drain current 3-4A

Thanks

Sujan

Switching Mosfet Dissipation

A A2 — Wed, 03 Apr 2013 22:45:03 GMT

Hi All,

I'm trying to measure the thermal performance of an existing buck converter using hyperlynx thermal. To perform the simulation correctly I need to know the power dissipations of the critical components including the switching mosfets.

First I tried using the power dissipation calculated in my spice software. This dissipation yielded a result that was too low, as confirmed by experiment. I then tried to measure the current through the mosfets by measuring the sense resistor voltage and the duty cycle. This still yielded temperatures that were too low. Then I simulated the circuit again and I multiplied the RMS current squared by the on resistance. This still yielded a low result.

Next, I multiplied the RMS Ids and Vds from the simulation together, yielding a 5W dissipation. This 5W is way too high, because with the particular thetaJC a junction temperature of 1000C was found.

Finally, I multiplied the average Vds and Ids together, which yielded the most realistic temps I have seen yet.

Ultimately, my main question is can the power dissipation of a mosfet be calculated by multiplying the average VDS by the average IDS? Is this the most accurate power calculation for thermal purposes? From all of the different combos I've tried this is the method that has yielded the closest results.

CSD87350Q5D Ron Parameter

Masazumi Ishii — Tue, 12 Mar 2013 15:29:53 GMT

Hello

it is a question about CICLON FET。

Please see the data sheet of CSD87350Q5D, and the page 3.
Zds（Q2 Sync FET）=1.2 mΩ(typ　　 Effective AC VOUT = 1.3V, IOUT = 20A,）
But、page 7. Please see Figure21 Rds=2.2 mΩ(tc=25 ID = 20A Vgs=5)

Ron of FET applies current limiting by ON resistance of FET, and becomes an important item.

the case where current limiting is calculated -- Rds or Zds -- which should be used?

Application:Sandy Bridge, Ivy Bridge　
Power supply：tps51219　and　CSD87350Q5D
Vin:5V
Vout:0.675V

Thank you

CSD25401Q3 PCB Trace Widths

Steven Gutierrez — Wed, 13 Feb 2013 21:52:35 GMT

It's awesome that these guys can funnel so much current for such small packages. It seems like the traces widths (found by using calculators online) would need to be huge to be able to handle the current thermally, so I'm wondering what the common strategy for accessing the pins is, since attempting to route to them using these huge widths would almost consume the footprint itself. Thanks!

CSD25401Q3 PCB Pattern

Steven Gutierrez — Wed, 13 Feb 2013 09:17:31 GMT

What are the two different patterns at the top of page 7 of the datasheet for CSD25401Q3, under the "Recommended PCB Pattern" heading? In particular, do I need the wings on the right one?

Power Dissipation for MOSFET CSD17303Q5

Sudha Rani B R — Mon, 11 Feb 2013 09:31:04 GMT

We are using the part CSD86350Q5D in our design. Under section Absolute Maximum Rating(Page2 of Datasheet) Power Dissipation is mentioned as 13W. Under section Power Block Performance parameter Power Loss is mentioned as Typ2.8W. In our design Vin = 12v, Vout = 1.05v. Iout= 20A

Now for doing thermal simulation what is the value we need to consider for power dissipation. Is it 2.8W

CSD17313 wrong dimension for PCB Pattern

Dan Lu — Thu, 27 Dec 2012 15:38:02 GMT

Dear support team,

our customer found the PCB pattern shown on datasheet seems wrong as below:

From calculation (2.3-1.4)/2 = 0.45 doesn't match the number of 0.46 on shown on datasheet.

Could you kindly help to advise what is the correct number to follow and revise the datasheet?

Thank you!!

Measured RDs(ON) is greater than that specified in datasheet

Sutej Reddy — Fri, 14 Dec 2012 05:16:18 GMT

Hi,

I am using a 30V N-Channel Power MOSFET, CSD17312Q5, in a power management converter. Knowing the current through the MOSFET, I tried to measure the VDS across the MOSFET during ON state through the oscilloscope. Datasheet says RDs(ON) is 1.2mohm for a VGS of 8V. Current through the MOSFET is 10A . Hence VDS across MOSFET should be 12mV. But I am observing it to be around 80mV. I am clueless why the MOSFET is showing around 8mohm RDs(ON). Such a high RDs(ON) is impairing the converter efficiency severly. Any ideas/suggestions?

Regards,

Sutej Reddy.

Gate driver needed for IGBT

jOze — Tue, 07 Sep 2010 08:10:56 GMT

I'm working with the 28027 piccolo dsp. I need to drive my pwm(3.3V) signal to switch an IGBT(15V cmos).

Does anyone know how I can do this with an IC? Which one??

Thank you very much.

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

Manuel Keesee — Mon, 03 Dec 2012 01:27:07 GMT

My input voltage will come from a photovoltaic array, 4X260W panels connected in series(35Volts X 7.5Amps) Optimum so:

Vin Max: 140Volts @ 7.5 Amps Vout: 20-30 Volts

Vin Min: 30 Volts Max Current Out: 52.5 Amps

Max Current in: 8 Amps or 32 Amps if panels are connected in parallel.

recommend on MOSFET

golan kormian — Wed, 21 Nov 2012 09:50:39 GMT

hi,

see the attached diagram:

please offer MOSFET for this application.

is it making difference using N or P channel?

CSD25302 and CSD16301 resistance while damaged

Rachel Coulter — Mon, 19 Nov 2012 16:31:22 GMT

Hello,

I'm looking for any information on specific failure data on CSD25302 and CSD16301. I would like to know if these MOSFETs could fail having a D-S resistance of around 5 to 10 ohms and able to conduct 3 to 7A continuously, while damaged. I know that there is some information about Reliability Data from the product folder but any further information would be greatly appreciated!

Any additional failure data on these two parts would also be greatly appeciated!

Regards,

Rachel

IGBT 75 A switching

Fatih Levent Yılmaz — Wed, 14 Nov 2012 14:38:16 GMT

Hello , I need an igbt which can handle a 75 A current switching around 500 kHz. Any advices ?

CREATING POWER MODULES FROM DISCREAT MOSFET ARE IGBT'S

WILLIE MCCAIN — Tue, 06 Nov 2012 01:49:48 GMT

I NEED HELP IN TRYING TO DETERMIN HOW MANY MOSFETS ARE IGBT'S I WOULD NEED

TO ALLOW 500VDC MAX. AT 150 AMPS DC CONSTANT TO FLOW IAM TRYING TO USE A 3" X 3" ARE 3" X 6" BOARD DEVICES ON BOTH FRONT AND BACK, WITH SINGLE ROW SIP CONNECTORS

SO I CAN STACK THE BOARDS IF NEED BE , IN CASE I NEED TO PUT 3 ARE 4 BOARDS TOGETHER TO GET THE RSDon LOW ENOUGHT TO ALLOW 150 AMPS TO FLOW WITH OUT OVER HEATING, AND NO NEED OF HEATSINK PER BOARD, I WOULD LIKE TO USE D2K PK'S

CALL ME DIRECTLY AT 561-853-4160 ANY TIME DAY ARE NIGHT INCLUDING WEEKENDS

THANKS SO MUCH THIS IS OF A URGENT MATTER

High Voltage, Low Current H Bridge Design

Alex52381 — Sun, 28 Oct 2012 16:36:29 GMT

Hello All,

I have been tasked with building an inverter system. I plan to use a H bridge to act as an inverter to drive the load. I would like to drive the H bridge with a microcontroller.

The system specifications are as follows:

1) Run off of a lipo battery (~4.2 to 3.2 V range)

2) Tolerate a high voltage supply up to 100V continuous

3) Switching frequency from 50 Hz to 5 kHz

4) Current draw is expected to be up to 1 A continuous

I would like to know if TI has a suggested MOSFET H bridge configuration. I am open to using PMOS devices on the high side to ease the gate drive requirements. It would be wonderful if there was a high voltage encapsulated H bridge IC.

One concern I have is that I would like the FETs to be able to be driven by a logic level input from a microcontroller. I know that power FETs often require a gate driver to charge their input capacitance.

Thanks!

H bridge driver

yashashree khachane — Wed, 17 Oct 2012 10:33:48 GMT

We need H bridge driver & MOSFET for requiement of 60V, 3A continuous & 6A peak current. please suggest.

Need help finding TI transistors A7611, & A7617

Ron Walrath — Thu, 12 Jul 2012 14:54:22 GMT

I have two mosfet transistors out of an old stereo i bought in 1976, that i've been unable to find a replacement or equivalent. They are TI & the info on them is in 3 lines. The first transistor is 1012, A7611, A-00, The second transistor is 1013, A7617, A-00. Any help locating these or a cross reference equivalent would be appreciated very much.

Thank You,

Ron W.

CSD25401Q3

Jason Yow — Mon, 27 Aug 2012 08:42:39 GMT

NewBie in the Spice Simulation.

Have build a simple circuit to use CSD25401Q3 PMOS as a switch to OPEN / CLOSE path to charge the capacitors.

By pulling Gate of PMOS to 5V, PMOS should open. (S-gate and D-gate should open)

From Transient Simulation, it shown the path still CLOSE, and continue charging capacitors.

Any thing i set it wrongly?

Thermal Resistance MOSFET

Jaime Chait — Wed, 25 Jul 2012 07:05:52 GMT

I have a basic question that hope someone can help me out.

When on a datasheet it is specified that RthJA = X degC/W on 1"sqr... does it imply that it is on a 1 layer board?.(CSD16411W3 is RthJA = 47degC/W)

The reason I'm asking is because on this paper http://www.nxp.com/documents/application_note/AN10874.pdf they show an improvement in temperature performance when using more than 1 layer and even better when using thermal vias to connect top and bottom layers.

If the datasheet number is assuming one layer then this numbers should be 40%-50% better if using this method (footprints are different but I think it should also apply).

Thanks in advance

Jaime

CSD86330Q3D layout

Titusc — Thu, 21 Jun 2012 21:02:00 GMT

hi there,

In the layout recommendation section for this part http://www.ti.com/lit/ds/symlink/csd86330q3d.pdf, there is a placement priority as shown:

In terms of priority of placement next to the Power Block, C5, C7, C19, and C8 should follow in order. My question is for the C19 and C8. Do it matter if C19 is placed closer to my buck controller instead? And lastly C8, it is a cap place at the EN/SS of my buck controller TPS40322. Why should it be brought up for the CSD86330Q3D layout?

Thanks,
Titus

Need help on UC2625

shankar raju — Sun, 24 Jun 2012 12:39:27 GMT

iam using the output of UC2625 to a mosfet driver which can accepts input only in the range of 4.5 to 5.5v so i want to connect PWR_VCC pin to 5V, so that i can connect it directly to the mosfet driver, is it possible to connect pwr_vcc to 5v

also specify the min & max values of Pwr_VCC

Thanks & Regards

Shankar

UCC24610 as a flyback synchronous solution in less than 1W application

Pradeepkumar Podal — Fri, 22 Jun 2012 08:23:03 GMT

Hello Evryone

I am planning to design a DC-DC flyback convertor with less than 1W output at 5V. Does it still make sense to use UCC24610 synchronous rectifier or am I better off with a schottky. I will mostly be operating in the green mode of UCC28600 due to my low power output

Regards