TIDA-00555: power supply of TIDA-00555

Zilin Li73

Part Number: TIDA-00555
Other Parts Discussed in Thread: TIDA-00810, TIDA-00835, TIDA-00080, TIDA-00834

Dear Experts,

I am a postgraduate student from Hong Kong. I am quite confused when I tried to realize the reference design TIDA-00555. I started with the power supply part, and after finishing the following as shown in figures, I can not get the voltage as shown in the schematic,+6V and -6V. Instead, the voltage across C77, C80 is about 19V, and C73, C75 with -19V. However, the voltage across D24 is correct +5V, thus D9 works well. Meanwhile, the voltage across D22 is -1.5V, instead of -5V, as a result, D11 does not work.

I have checked if there is something wrong with about the soldering, and tried other three PCBs, but can not find anything. So, I am wondering if there is something I need to be noticed. I would be appreciated any replies!

over 6 years ago

0 Kallikuppa Sreenivasa over 6 years ago

TI__Guru**** 160009 points

Hello Zilin Li73

Thank you for considering TIDA-00555. The output is transformer dependent and The Transformation ration between 1-2 : 4-6 , 2-3:4-6 is 1:1.64.

Make sure the transformer you use has the specified transformer ration and please check with wurth to get those custom made transformers.

See the link for the specs

katalog.we-online.de/.../750342271.pdf

Thanks

Sreenivasa

0 Zilin Li73 over 6 years ago in reply to Kallikuppa Sreenivasa

Prodigy 40 points

Dear Sreenivasa,

Thank you for your reminding. I have checked that I used a wrong transformer.

0 Kallikuppa Sreenivasa over 6 years ago in reply to Zilin Li73

TI__Guru**** 160009 points

Hello Zilin Li73

Good to hear that.

We have other TI designs including TIDA-00080, TIDA00834, TIDA-00810, TIDA-00835 that you could refer to based on your application need.

Thanks

Sreenivasa

0 Zilin Li73 over 6 years ago in reply to Kallikuppa Sreenivasa

Prodigy 40 points

Dear Sreenivasa,

I have replaced the transformer with the specific one, 750342271.

However, I am curious why the output voltage( the voltage across C79) is -1.5 V, and D11 does not work? Is not the output voltage -5 V?

I checked the datasheet of TPS7A3001DGNR, it seems that values of R94, R95 can not regulate the output voltage to -5V, but to -1.5V.

Thank you very much your reply!

0 Kallikuppa Sreenivasa over 6 years ago in reply to Zilin Li73

TI__Guru**** 160009 points

Hello Zilin

Please note that in the design, the negative voltage is used for protection. See the note n the schematics you have sent above, the note says the LDO is confi-gured to -1.5V.

The -1.5V is configured to protect the amplifier and also ensure no errors due to the leakage current of the diode during normal operation.

The output is as expected and you can continue testing the design.

There are ways to avoid the negative supply and we have shown this in TIDA-00834. You could alternatively consider that approach.

Thanks

Sreenivasa

0 Zilin Li73 over 6 years ago in reply to Kallikuppa Sreenivasa

Prodigy 40 points

Dear Sreenivasa,

Thanks so much your reply! And thanks the recommendation for TIDA-00834.

The output voltage is configured to -1.5V, then, why the voltage of node TP16 is labeled -5V, should not it be labeled -1.5V?

And, when the output voltage is -1.5V, it does not provide enough voltage for D11, as a result, D11 is not lighted. Does D11 aim to indicate that the voltage of node TP16 is -5V?

0 Kallikuppa Sreenivasa over 6 years ago in reply to Zilin Li73

TI__Guru**** 160009 points

Hello Zilin

D11 can be used based on the application need.

We have some applications where we use the -5V and hence use the indication.

Since you are looking at inly protection, -1.5V is fine and can continue the testing.

Thanks

Sreenivasa

Simulation, hardware & system design tools

Simulation, hardware & system design tools forum

TIDA-00555: power supply of TIDA-00555