WEBENCH® Tools: AC/DC Bipolar Supply +/- 5VDC & a 3.3VDC Supply

Hi Wesley,


Thanks for pointing the issue out. We will take a look at why the -5V design is showing error. In the meanwhile, you can use the following individual designs to work on your project. You can edit the designs if you have some specific requirements.

AC-> DC: 12V 0.7A UCC28630 design: webench.ti.com/.../SDP.cgi
The 0.7A output current is necessary to drive the loads

12V -> 5V/0.5A buck: webench.ti.com/.../SDP.cgi

12V -> -5V/0.5A inverting buck design with TPS63710: webench.ti.com/.../SDP.cgi

12V -> 3.3V/1A buck: webench.ti.com/.../SDP.cgi


You can even specify each of these 4 design requirements individually (single output option) to get more solutions if you like. We apologize for the inconvenience caused due to this.

Regards,
Amod

Ok, I guess I can see what you are saying now. Please check back as I will keep communicating on this post.

I did do what you are saying and just create single loads and then how can I send all these to one PCB?

Again shortly later on today I will post all my designs... So you guys can help walk us through this process. Thanks for your time, 

Wes

Wesley,

There is not a good way to get the PCB for the entire design at this point. You will just have to use the individual layouts or datasheet recommendations as a guideline today to layout the individual designs on one board.

Regards,
Amod

Please see my additional comments I still need your assistance...

So I still need some help we are doing a smart outlet on a PCB using the TI CC3200EVAL board with an NFC Transceiver booster pack DLP-7970ABP stacked together. We are trying to do our own spin of a smart outlet by using voltage on channel 1 and current on channel 2.

We have on Channel 1 differential amp AD629BNZ by Analog says it has a max consumption on +/- 25mA it then feeds a Variable gain op-amp LTC6910 by Linear consumes +/- 25ma then goes to the cc3200 AICH1.

Next, We have on Channel 2 differential amp AD629BNZ by Analog says it has a max consumption on +/- 25mA it then feeds a Variable gain op-amp LTC6910 by Linear consumes +/- 25ma then goes to the cc3200 AICH2.

I was going to run these 4 devices on +/- 5VDC because the LTC6910 can only run max 0 to 10VDC swing.

Also regarding channel2 we had too much noise on our shunt resistor so we are going with an ACS712 by Allegro data sheet states it consumes no more than 10mA supply 0 to 5vdc

The worry is the TI CC3200 states it can consume as much as 500mA during a calibration process I guess and we still have the DLP-7970APB board too and it sounds like it can take max of 150mA...

I also came across the TIDA-00534 board that is recommended to drive the TICC3200 board it has the LP38692-ADJ set to give 3.3V at 1Amp. so I bought an eval board on Digikey LP38692EVAL-ND.

So, in the end, that's what I want to drive since there is good data from TI stating the TIDA-00534 method works and is safe. Let's talk about the power supply though don't you have a TI eval board that lets says we know TI did the work on making a flyback 85-265VAC to 5 USB board. I have seen some go from 1Amp to 2Amps where we know they work I can redraw it on PCB software.

But then it feeds a good into an LDO +5VDC for the +5vdc rail 500mA.

also feeds the LP38692-ADJ set at +3.3VDC 1amp feeding the TIc3200 and DLP board I don't think the chip load will be more than 500mA so heat on that chip I saw can get really bad on the webtherm software.

We switch it over to a negative LDO -5VDC rail 500mA

Please and thank you but this is my first major project I just dunno if I should a unit from scratch using the TI WEBENCH I see it wasn't liking some of the values from doing the AC to DC.

So I hope you get back to me and I can get cranking on this design. Hopefully, you will see my post so I can get moving forward. I will be using NI Multisim to Ultiboard for this entire design.

Hi Wesley
Can you please list out the vin, vout that you are looking for every rail? The requirements that you have are very common and WEBENCH should be able to recommend a solution.
did you try opening the designs that Amod shared with you?
regards,
Gerold

Ok so the issue isn't what Amod gave me its what does work in WEBENCH but it looks like the power supply from AC to DC you can't get the Flyback transformer. So basically I want something that the TI-Designs has already built and tested and this is the unit i think will work for my AC/DC conversion. Its 85-265AC to 12VDC @1Amp. This is plenty of power for our design... Then I need to just create the loads of +5VDC and -5VDC but the tricky part is I have read the TIDA-00534 Voltage regulator for the CC3200 eval board it has the LP38692-ADJ set to 3.3VDC upto 1A so I need to use that part. I guess it can get really hot is the issue I personally don't think I will draw more than 650mA worse case on this chip.. I've tried the Power Architecture software but it won't let me use this but some if you read the TIDA-00534 they say you can use a 5V usb wired to this board and you can power up the cc3200 eval board. Let me add a drawing so you can see what I'm trying to do...

I think design PMP20634 in the TI-Designs catalog will work as long as I can find the parts... thats plenty of power to drive my rails and the TIDA-00534 chip but i guess heat is an issue. Here is a pic of the AC/DC or 120VAC to 12VDC-1Amp 12Watt supply that look simple to re-create.

link below....

www.ti.com/.../PMP20634

Hi Wesley, 

   I searched WEBENCH for 85V to 265V, 12V @0.1A design and found that UCC28880 or UCC28881 could work for your needs as well. Can you confirm that 0.1A load on 12V Vout would be enough for your needs.

https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=55BCCE6EFD934DDC

Here is a link to the design.

You can also take a look at the EVM for this product. http://www.ti.com/lit/ug/sluub56c/sluub56c.pdf

This should be a much smaller design and it does not need a transformer (hence non-isolated). Do you have an isolation requirement for your product? 

If you have an isolation requirement, you could still go ahead and use the PMP20634 and operate it at much lower current as you can see from the test results given in the PMP20634 webpage.

Regards,

Gerold

100mA? I don't think thats enough power correct? I need atleast 12V at 800mA power supply if you add up all the components but like I said I'm trying to get from the 12VDC to 5VDC to the LP38692-ADJ 3.3VDC 1Amp thats were i need help I am going to build up the PMP20634 then i just need to supply the three loads im thinking like this

12VDC 1amp to these loads below.....

--------------------------------- +5vdc 350mA max = 1.75watts
--------------------------------- -5vdc 350mA max = 1.75 watts
---------------------------------+5vdc 1amp to the LP38692 3.3 VDC a 1amp = 5watts + 3.3watts = 8.3watts

total power supply loads needed = 11.8Watts

Please double check my math but the issue really is load item #3 the 5VDC 1amp says it will make the lp38692 way to HOT so I tried 4.00VDC at 1amp but can i do this?

Also I've tried it on the power architect but it just wont let me build it with an LP38692-ADJ 3.3V 1.0amp

Hi Wesley
Is there a reason why you would want an LDO? Because you are deriving 3.3V from a 12V Vout, the drop across the LDO would be huge causing it to heat up. You could try a switcher to go from 12V to 3.3V or 5V at 1A very easily.
If you are specific about using a LDO for low noise requirements, you could see if you can tolerate 5.5V Vout on your 0.35A rail. So make it a 1.35A rail. Then you can use the LP38692 to step it down to 5V easily.

Here is a link to the Power Architect project using only switchers. I have excluded the -5V rail, as currently negative rails are being fixed in Power Architect.
webench.ti.com/.../OpenPublicSharedProject.jsp

If you want an LDO suppply, here is a power architect design that can be designed using LDOs LP38690

webench.ti.com/.../OpenPublicSharedProject.jsp

Regards,
Gerold

I need LP38692 to be at 3.3V 1Amp. Yes I need and LDO for powering up the CC3200 and the DLP-7970APB boards i think the loads of these two boards are no more 400mA for the cc3200 and 150mA for the DLP-7970APPB total 550mA thats why i bought the LP38692-ADJ board from digikey link below..

www.gs.com.eg/.../2213299_1.pdf

but i can't get it to work in WEBENCH or i don't know the correct chip to buy meaning a TPS562XX... like a TPS562210 on its own bus line...

Hi Wesley

   As I mentioned earlier, you can use the LP38692 provided the input is lower, such that the drop across the LDO is not high. 

I was able to create the design using LP38692 in WEBENCH for a 4.3V Vin, 3,3V Vout @ 1A

webench.ti.com/.../SDP.cgi

You can refer to the Power Architect design that I shared with you to step it down to the intermediate 4.3V rail.

Regards,

Gerold

Does it have to be 4.3V input to this or can you do 4.00V?

So check this out I started over and just looked for setting my  DC inputs to be this on the starting screen...

Redid it with this picture TPS563209 max 0.76

Then i clicked on the TPS563209 then I clicked on ADD the LDO and picked it and this worked.... but I still want to make the TPS563209 a 1AMP max design sincee the TIDA-00534 workeed but that put out 5 Volts what do you think i should do???

Hi Wesley
You can operate the TPS563209 at 12V Vin, 5V Vout @ 1A without any issues. You can follow this with the LP38692 operating at 1A.

Please see attached designs
webench.ti.com/.../SDP.cgi
webench.ti.com/.../SDP.cgi

Regards,
Gerold

ok so if we go back now calculating by hand how many watts will just this run?

will my 12-watt power supply be enough???

One more thing could i use these thses parts instead the LM7805CT/NOPB rated +5vdc 1amp and then LM7905CT/NOPB rated -5VDC rated at 1 amp out of that power supply? It woul dbe esier for me to solder these