WEBENCH® Tools/TPS562200: TPS562200 is warming up or does not give the desired output.

Mehmet Eyup Arslan

Part Number: TPS562200

Tool/software: WEBENCH® Design Tools

Dear All,

I designed the circuit with TPS562200 that the input voltage is 5-12V and output voltage is 3.3V 1A. I used the WEBENCH Design Tools and TPS562200 datasheet.

I produced the 20 pieces prototip board and 14 boards worked properly. I'm deal with non-working boards. I disassemble processor non-working 6 boards. I noticed that ground and 3v3 of 4 processor pins shorted.

I think the reason for this is the regulator TPS562200.

I decided to look at the output voltage of the regulators. Although I give the same voltage at the input, 1 of the regulator output 1.66V and the other 4.07 volts. The other 2 one it attracts current in a wavy manner

and gets very hot.I checked the components wrong and tried again but the components were correct.

As a result, 1 regulator output 1.66V

1 regulator output 4.07V

2 one attracts current in wavy manner and gets very hot.

İs there someone who can help? What could have done wrong. 16 out of 20 working boards.

lg_gway_v4.0.pdf

over 6 years ago

0 Jason Wang (BSR-MV) over 6 years ago

TI__Genius 9550 points

hi,
The schematic is ok for me. Please upload the layout for check.
Also, tell us the inductor's parameters. (or part number)

0 Mehmet Eyup Arslan over 6 years ago in reply to Jason Wang (BSR-MV)

Intellectual 745 points

Hi Jason,

Firstly, thank you.

İnductor Part Number : NR4018T3R3M

Digi-key Part Number : 587-5932-2-ND

The board is 2 layer.

I'm waiting for your answer.

0 Jason Wang (BSR-MV) over 6 years ago in reply to Mehmet Eyup Arslan

TI__Genius 9550 points

hi,
1. for NR4018T3R3M, current saturation is only 2A which is small for your application. Should be higher than 3.2A
2. Layout. Trace from SW to inductor, too narrow. Refer datasheet page 23, Figure 50 "Typical Layout"

0 Mehmet Eyup Arslan over 6 years ago in reply to Jason Wang (BSR-MV)

Intellectual 745 points

Hi,
1. Why the current saturation should be higher than 3.2 A. I don't understand. I chose this inductor because I thought I would get max 1 A at the output.
2. Layout. I understand.

Thanks,

0 Jason Wang (BSR-MV) over 6 years ago in reply to Mehmet Eyup Arslan

TI__Genius 9550 points

Hi,
For this device, the OCP theshold is 3.2A (typical; refer datasheet page 6).
1. when the Vout short by mistake, Iout max should be higher to ~3.2A
2. When the load transient(load change from light to heavy suddenly), inductor current maybe higher than 2A.

0 Mehmet Eyup Arslan over 6 years ago in reply to Jason Wang (BSR-MV)

Intellectual 745 points

Hi,

The information you provided was very helpful.
Thank you so much.

Power management

Power management forum

WEBENCH® Tools/TPS562200: TPS562200 is warming up or does not give the desired output.