TPS2493: UVEN pin Control problem...

Changwoon Eom1

Prodigy 105 points

Part Number: TPS2493
Other Parts Discussed in Thread: CSD19537Q3,

The MCU is controlling the UVEN pin through Q7(2N7002).

If there is no load, the output is well controlled.

However, the output is maintained even if the load is connected and "0" low is set on the UVEN pin.

load has the following characteristics:

R : 48 ohm

C : 6,600uF

The UVEN pin is set to 0, but the GATE pin outputs, and Vout also outputs power.

When the load is removed again, the output is maintained even after controlling the UVEN pin.

over 6 years ago

0 Rakesh over 6 years ago

TI__Guru** 107121 points

Hi Changwoon,

Do you mean that Vout and GATE stays high even if UVEN is forced '0' ?

Can you share some test waveforms

Vin, Vout, GATE, Timer
Vout, GATE, Timer, input current
Vout, GATE, input current, UVEN voltage

Also, send me filled up design calculator. It is available at http://www.ti.com/product/TPS2493/toolssoftware

BR, Rakesh

0 Rakesh over 6 years ago in reply to Rakesh

TI__Guru** 107121 points

Hi Changwoon,

Any update on the above to debug.

BR, Rakesh

0 Changwoon Eom1 over 6 years ago in reply to Rakesh

Prodigy 105 points

I'm sorry for late reply.

The measurement waveform you requested has not yet proceeded.

We connected our 'load' to the TPS2493EVM and measured the IMON and found that the 6V level was maintained around 100us.

As a result of measuring the temperature of the N-channel FET(CSD19537Q3) currently in use, it measured up to 130 degrees when booting up.

Therefore, replacing the FET did not control the power output of the TPS2493.

The power input status is as follows.

Vin : 48V

Imax : 2.5A

Suspected of FET destruction, we replaced it with a high capacity FET (IRF540NS) on a new PCB.

And the temperature was raised to 70 degrees and operated normally.

0 Rakesh over 6 years ago in reply to Changwoon Eom1

TI__Guru** 107121 points

Hi Changwoon,

Is your problem solved with new FET ?

BR, Rakesh

0 Changwoon Eom1 over 6 years ago in reply to Rakesh

Prodigy 105 points

I'm still testing it with a new FET, but there are no problems yet.

Will the TPS2493 be affected when the FET is destroyed by overcurrent or high temperature?

The TPS2493 also had to be replaced with the FETs for normal operation.

0 Rakesh over 6 years ago in reply to Changwoon Eom1

TI__Guru** 107121 points

Hi Changwoon,

Yes, it is possible to get controller also damage during the process. A damaged/ failed FET would put stress on the GATE section of the controller TPS2493.

BR, Rakesh

0 Changwoon Eom1 over 6 years ago in reply to Rakesh

Prodigy 105 points

Thank you for answer.

If you have any questions again I will leave.

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TPS2493: UVEN pin Control problem...