Part Number: LM5113
Is TI aware of any issues with the LM5113 Spice model when parasitic inductance is placed in series with the Vcc pin and the Vss pin. In my model I am attempting to account for parasitic inductance between the decoupling cap and the Vcc/ Vss pins. The circuit is running at 30 MHz. What I observe is if I place an inductance of > 2.5nH in series with these pins the output of the device fails to produce a proper square wave. When the inductance is <2.5nH the circuit works properly. .Any thoughts on this? Thanks
In reply to Alberto Doronzo:
In reply to Michael Brand:
I am running my simulation on Simetrix.
There are a couple of things that might help running the simulation :
1. ensuring that your voltage supply for both high and low side is stiff (except for the extra capacitance), as at those frequencies it might be difficult to charge up the HB cap.
2.because of the extremely low time constant at nodes, the simulator might not converge, you might have to detune the parasitic instructors with a parallel resistor.
Please see below the simulated waveforms for both high gate (wrt the switched node) and the low side gate - the spikes are likely an artifact but there is no way of checking as the LM5113 is not capable of those frequencies. Also see the setup below.
If you are interested in higher frequency applications, we can have a private conversation about your needs.
Thank you and best regards,
Thanks for the information. I will try to run my circuit on SIMetrix to see if it makes a difference. I should point out that I am running the high side driver as a ground referenced circuit off of the same 5V as the low side driver. I am therefore not using a bootstrap capacitor. I will contact you later about higher frequency operation. Thanks
I have copied the LM5113 spice model into my SImetrix circuit file. The transfer went fine. I used the unencrypted pspice model from the TI web site. I can not make it work. The high side driver switches properly but the peak of the waveform only reaches 3.6 volts. I would expect it to be closer to 5V. The low side driver output is just noise. What model did you use and how did you make it work? I should point out that I have been successfully running the LM5113 model on LTSpice with no problem. I had to move to Simetrix for other reasons. Further this one day turnaround to hear back from you is not working. I need to get answers much quicker. This modeling issue is severely delaying the completion of my task. Is their away we can have direct communication by phone. Thanks
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.