TPS92560MR16BSTEVM with E-transformer

Dear uMin
I'm Trinh Dieu. Nice to meet you!
I also have the problem as your problem but my E-transformer is Tridonic.
Has your problem been fixed ? Please share the solution with me !
My email : dieu.trinh_van@allyparkgroup.com
Thank you verry much !

Hello uMin,

Most of the E-transformers used for MR-16 were designed for high wattage resistive loads (incandescent/halogen at 50 watts).  The TPS92560 circuit draws much less power so it is a bit more difficult to make work properly.  I would check to make sure the wires leading to the EVM are short and those to the LEDs are also short.  Check to make sure R1 and C1 are on the board and R1 value measures correct.  They help the E-transformer run correct.  You are also running at 230 volt input which makes this more of a challenge.  If you have more than one EVM try running two in parallel.  If you don't try adding some small resistor load in addition to the EVM to see if you can make it operate correct.  I would start with 1 or 2 watts additional resistive load, 144 ohms and 72 ohms and go down from there until the unit operates, just to see how far from correct operation you are.

Another thing that can be causing issues in the input voltage distortion.  If there is higher dv/dt than the normal sinusoidal waveform the EMI components in the E-transformer can be causing less current to be demanded at times causing circuit malfunction.

Regards,

Hello Irwin Nederbragt

Nice to meet you !

I also have problem with TPS92560 for MR16 and  E-transformers

I want to MR16 lamp work  with E-transformers of Tridonic ( TE-0105 U 1–10 V) . I design based TPS92560MR16BSTEVM

but my circuit runs incorrectly according ( not operating ) as the design.

The power of E-transformer when no load is 1.5W.

When i conect my circuit  with this E-tran, the total power ( Pe_trans + Pdriver + Pled) is 12W .But I measured power of LED (Pled) is 3.2W.

When the circuit runs, IC is very hot, after about 3 minute, IC is burnt.

So, to my circuit compatible with this E-transformer , what I have must be modified ?

I'm looking forward to hear from you soon

My email : dieu.trinh_van@allyparkgroup.com
Thank you verry much !

Hello Trinh,

The MOSFET you are using is not the right device for this.  It is a 600 volt device with high gate charge, 78 nC, and it appears your switching frequency is quite high so the TPS92560 will get hot.  I would find a different MOSFET with low Qgtot to start with.  Have you measured the switching frequency?

I looked up the electronic transformer, Tridonic TE-0105 U.  It states; "Not suitable for operation with MR16 LED bulbs".  It is 1-10 V dimming, do you know how it dims, does it reduce output voltage or current?  What does the output of this transformer look like when dimming on a standard MR-16 bulb?  On phase cut dimming the voltage amplitude does not change only a portion of the waveform is cut where the TPS92560 circuit will not run.  So as the dimmer is turned down a larger portion of the AC waveform is cut to cause dimming.  The datasheet also states it is "phased out".

If your load is 9V/0.45A mA which is a fairly small load for an E-transformer.  Have you looked at this circuit with an oscilloscope to see if it is operating correct?  What does the input voltage look like, the MOSFET drain voltage, LED voltage and current?

Have you tried other E-transformers or running this from a DC input?

Regards,

Dear Irwin Nederbragt
Thank you for reply.
I replaced the old mosfet as part: CSD17308Q3 ( 5.1nC) but the total power ( Pe_trans + Pdriver + Pled)still is 13W, Pled = 5.4W
=>The power consumption on the driver circuit is 13W-5.4W - 1.5W , about 6W and TPS92560 still is very hot.
i don't know, why the power consumption in my driver is lager, so the TPS92560 will get hot.
Can you tell me cleary about :
It is 1-10 V dimming, do you know how it dims, does it reduce output voltage or current? What does the output of this transformer look like when dimming on a standard MR-16 bulb? On phase cut dimming the voltage amplitude does not change only a portion of the waveform is cut where the TPS92560 circuit will not run. So as the dimmer is turned down a larger portion of the AC waveform is cut to cause dimming. The datasheet also states it is "phased out".
I don't understand your mean. Please tell me if you need anything infomation about my appilication.
Thanks you very much !

Hello,

What is the switching frequency?  Have you measured it?

Can you place a 6-8 watt resister load on the output of the Etransformer and see what it does (Pin, Pout)?

Phased out means they will not be providing that E-transformer for much longer.

Do you know how this Etransformer dims?

Regards,