LM73606: Simulation, hardware & system design tools forum

christophe vidon

Part Number: LM73606

Tool/software:

I have tried to simulate on PSPice_for_TI a simple LM73606RNP with the schematic inspired from Webench tool. Input 15V out: 9V All other parameters standard : SYNC, BIAS to GND; RT SS-TRK N.C. The signals at the inputs are correct: VIN, EN, VCC, RT are OK. But the outputs signals show #0V : CBOOT, SW, FB, BIAS ... I do not understand using standard schematic working well on Webench [simu on Webench is OK ...] that does not work ... I use the std biblio LM73606RNP_TRANS by default. It seems that there are two peaks on SW / CBOOT at 40us and then ... 0V definitively as if there is a problem of boot / init ... Please help me I cannot see any mistake as all the schematic is standard based ...

7 months ago

0 Joshua Austria 7 months ago

TI__Mastermind 27800 points

Hi,

What load on output is being used to simulate this in PSPICE for TI?

Additionally, can you please note what was changed from the original schematic on PSPICE?

Thank you,

Joshua Austria

0 christophe vidon 7 months ago in reply to Joshua Austria

Prodigy 30 points

Hi,

About the output load : 2 ohm (so 9V / 2 = 4.5A load)

I changed the discrete parts to fit to the webench simulation ... (except for the load I do not understand what is your load in the webench ...)

0 Joshua Austria 7 months ago in reply to christophe vidon

TI__Mastermind 27800 points

Hi Christophe,

Does the default configuration in PSPICE for this part work on your machine? If so, can you share that schematic and its results?

Thank you,

Joshua Austria

0 christophe vidon 7 months ago in reply to Joshua Austria

Prodigy 30 points

I used the default config profile.

0 Joshua Austria 7 months ago in reply to christophe vidon

TI__Mastermind 27800 points

Hi Christophe,

Apologies for the confusion. By default configuration, I mean the schematic that comes default when you download this PSPICE model from TI.com. There should already be a validated circuit that will startup properly. If this setup does not work on your machine, then we can suspect that the issue lies with the machine being used or the program setup, as opposed to the schematic itself.

Thank you,

Joshua Austria

+1 christophe vidon 7 months ago in reply to Joshua Austria

Prodigy 30 points

OK Joshua ! I used the (LM73606) pspice model : snvmbe5.zip that we can download from TI site, and right that works well on my pspice simulator ... for instance here the startup simu (10 min to finish it on my PC) But that does not do exactly what I want (this is 12V > 5V). Nevertheless I can keep it as a reference and slightly modify it until it fits as what I want ... So thank you for your support I will come back to you if I cannot do what I aim to. In a second time after I will finalize my design is it possible to make a review of my schematic by TI ? I also want to design a more complex stuff: TPS7H5007 + TPS7H6015 based, how can I do as it does not exist a complete TI simulation of both ICs together ? What do you advice to me for that design ?

0 Joshua Austria 7 months ago in reply to christophe vidon

TI__Mastermind 27800 points

Hi Christophe,

Glad to see that the PSPICE model works. Should you have any issues further, please feel free to come back to this thread.

In terms of a review of the schematic, we can do that. Please open a new thread in that case.

Finally, in terms of simulating IC's together, this should be feasible, granted that all the proper libraries and device's are imported correctly in PSPICE for TI. This may take some time, and increase complication, but this should be feasible.

Thank you,

Joshua Austria