Hi All I have setup a simulation in LTSpice with components selected that I wish to create a real PCB for but wanted to simulate it first, I wondered if anyone wouldn't mind looking at it and making any suggestions of how I could improve this. (It takes in 12V and outputs 60V @ 5A) I'm personally worried about the intial peak current, will the inductor be fine with this? I am also worried about the ringing present in the voltage which can be seen when zooming in. Any suggestions would be greatly appreciated. Simulation is attached with this post.

Kind Regards

Art

 

One thing I forgot to add to this simulation was a load of 12 Ohms across the output so the current (5A) is being drawn.

Thanks
Art

 

Morning art,
I have tried running the asc file, but it never converges, runs for ever.?
E

Added the 12R load, still the same.

 

Morning art,
I have tried running the asc file, but it never converges, runs for ever.?
E

Added the 12R load, still the same.

Morning art,
I have tried running the asc file, but it never converges, runs for ever.?
E

Added the 12R load, still the same.

Oh right that's unusual, I know it takes a really long time for the simulation to finish do you know what I need to change on my side? Or can you edit what I have uploaded in any way?

 

hi,
I will give it a look over.
E

 

hi,
I will give it a look over.
E

thank you

 

hi,
Just ran the the LT3758 model test sim, runs OK, so I guess that model is OK, will keep looking.
E

 

See

 

See
View attachment 145508

wow thank you for this may I ask the reasoning for the ferrite bead for future referencing this is my first time designing something of this nature

 

hi,
Just ran the the LT3758 model test sim, runs OK, so I guess that model is OK, will keep looking.
E

great thank you

 

hi,
Nice catch Bordodynov, never had cause to use a ferrite model before.
Eric

 

hi,
Nice catch Bordodynov, never had cause to use a ferrite model before.
Eric

Do you think there is anything else that should perhaps be added to improve it even further?

 

See
View attachment 145508

one thing I did want to confirm is the current through the inductor is this coil craft inductor rated appropriately or should I change it to something else?

 

hi,
Nice catch Bordodynov, never had cause to use a ferrite model before.
Eric

Do you think the Inductor is suitable, I'm mainly concerned about the initial spike at the beginning?

 

The current jump is short-lived. It occurs without the participation of a chip. In order to remove the jumps of current through the inductance, it is necessary to slow down, i.e. stretch the front of the input voltage in time. This can be done using a powerful transistor, a 100kΩ-1MΩ resistor and a capacitor. In order for this circuit to quickly return to its original state when the voltage is removed (disconnected), a diode must be added. I removed comparatively low-frequency oscillations of the output voltage using a resistor and Schottky diode in the gate. Short-term emissions remain. It is these emissions and filter the beads. Resonant phenomena can occur with inductances.

 

The current jump is short-lived. It occurs without the participation of a chip. In order to remove the jumps of current through the inductance, it is necessary to slow down, i.e. stretch the front of the input voltage in time. This can be done using a powerful transistor, a 100kΩ-1MΩ resistor and a capacitor. In order for this circuit to quickly return to its original state when the voltage is removed (disconnected), a diode must be added. I removed comparatively low-frequency oscillations of the output voltage using a resistor and Schottky diode in the gate. Short-term emissions remain. It is these emissions and filter the beads. Resonant phenomena can occur with inductances.

Hi great thank you for the explanation really appreciate it, so in practise if I were to create a PCB with this circuit would the jumps in current be present, if so could you show me an LTSpice model of what I should add in order to avoid this?

Kind Regards
Art

 

I'll show it a little later.

 

I'll show it a little later.

ok great thank you very much

 

See

 

See
View attachment 145529

Hi there would you mind looking at the new post I put up still a boost topology but slightly different that I simulated in Lt Spice it's a synchronous boost converter this time any help would be greatly appreciated.

Kind Regards

Art