LM5155: LM5155 Boost Output to 200V+/-10%

Hi Mahammadirfan,

Thanks for reaching out. 

LM5155 can operate down to 2.97V when Bias and VCC are connected. The input can even go down to 1.5V, if the Bias pin is supplied with a voltage higher than 3.5V (from external).

Mahammadirfan Saiyed said:

provide part which can support minimum 2.5V input and can provide the boost output of 200V , 0.2-0.5A.

This is not realistic for a single stage. Also not for flyback topology. You can think about a 2- or 3 stage solution for this.

Best regards

Moritz

Hi Mortiz,

Thanks for your response.

Can you guide me for the reference design with 2 or 3 stage solution ? I have seen one device which is making 200V using the part #LM5155. So requested it. I dont have much details of though.

The sheet I have used is able to do it using this chip # LM5155.

4265.LM5155_56_Quickstart_Calculator_for_Boost_Converter_Design_V1_1_1.xlsx

Thanks

Hi Mortiz,

What if I use the LM5155 in DCM mode and for less than 50mA load current ? I don't want to use 2 or 3 stage design to avoid cost implications.

"LM5155 can operate down to 2.97V when Bias and VCC are connected" I can do this.

Hi Mortiz,

AWaiting for your feedback.

Thanks

Hi Mortiz,

Thanks, I will go through it and get back to you.

Hi Mortiz,

I have gone through the document and measured as follows:

• VIN=3V

• VOUT=200V

• IOUT=0.03A

• L=1.5 μH

• At 100 kHz → Duty ≈ 7.7%

• At 2 MHz → Duty ≈ 34.4%

• At 100 kHz: tON=0.077×10 μs=0.77 μs≫50 ns

• At 2 MHz: tON=0.344×0.5 μs=0.172 μs=172 ns≫50 ns

• So it’s feasible with L=1.5 μHL 

  $Is\; my\; calculation\; are\; correct\; ?$

Can I use LiDAR Power Supply 2 As per Fig 10-8 which shows Voltage Tripler for Vout =200V and input VIN = 2.97V - 16V by shorting VCC and BIAS ?

I am also trying to find simulation tool for this but unable to find it with power bench due to the limitation

Hi Mortiz,

Thanks for your feedback.

I have downloaded and used Power stage Designer but its not that much useful and conclusive. PFA. Its directly showing the inductor value only and nothing else.

Also online tool with this input is showing error like no matching circuit even with boost drop down menu or it is providing circuit with transformer and we dont want to go with the transformer based design.

Regards,

Mahammadirfan Saiyed

Hi Mortiz,

Sure I will do it .

Can you suggest me the EVK of LM5155 or similar with Link which I can use to generate 200V/50-100mA ? 

I can use few external parts incase needed.

Thanks

Hi Mahammadirfan,

You could use the LM5155EVM, but you would need to change many parts.

Inductor, FET, output caps...

Best regards

Moritz

Hi Mortiz,

In that case it will not be useful.

Let me order IC only and make the PCB at my end with coupled inductor to increase the output voltage to 200V around as below. I hope this will work without PSR/SSR feedback mechanism .

Hi Mortiz,

Not Exactly, but something like below, though not used of TINA but tried hard for this to get the exact behavior but its throwing error like below.

Also tried ripple ratio 200% but may be there is some error as well.