LM5156: LM5156

ADITYA MENE

Part Number: LM5156
Other Parts Discussed in Thread: LM5155

Tool/software:

Hi Sir,

I am planning to design a power supply using the LM5156 controller, with a programmable output voltage ranging from 0 V to 150 V, based on the Program-Controlled Vout Power Supply technique described in TI's documentation.

I would like to know whether this approach is practically feasible with the LM5156 for such a wide output range—especially with output going as low as 0 V.
Could you please advise on the following:

Is this solution practical and reliable for real-world implementation, particularly when sweeping from 70 V to 150 V?
Are there any limitations or key design considerations when using LM5156 in this configuration?
Can you suggest any reference designs or application notes for implementing a digitally controlled feedback path (e.g., using DAC or filtered PWM)?
What are the stability and loop compensation considerations across such a wide dynamic range?

Supporting documents :

https://www.ti.com/lit/an/slvaej4/slvaej4.pdf?ts=1751106246167&ref_url=https%253A%252F%252Fwww.google.com%252F

https://www.ti.com/lit/ds/symlink/lm5156.pdf?ts=1751028123042

Your guidance on this would be highly appreciated.

2 months ago

0 Mounika Girish 2 months ago

TI__Intellectual 2426 points

Hi Aditya,

Thank you for using e2e forum.

ADITYA MENE said:
LM5156 controller, with a programmable output voltage ranging from 0 V to 150 V,

It is possible to have the programmable output voltage from 0V to 150V using flyback or SEPIC.

ADITYA MENE said:
Is this solution practical and reliable for real-world implementation, particularly when sweeping from 70 V to 150 V?

With flyback or SEPIC,it is possible and also on adjustable output

ADITYA MENE said:
Are there any limitations or key design considerations when using LM5156 in this configuration?

Depends on which topology and also on the specs like input voltage, output power and load.

ADITYA MENE said:
What are the stability and loop compensation considerations across such a wide dynamic range?

More challening to find the suitable compensation but the circuit has to be stable under all operating points

Please take a look at the https://www.ti.com/tool/POWERSTAGE-DESIGNER

Best regards,

Mounika

0 ADITYA MENE 2 months ago in reply to Mounika Girish

Prodigy 60 points

Hi Mounika,

First of all thank you for your valuable response. I am planning to implement this technique for Boost convertor topology. The specifications are as follows:

Input Voltage 18V DC to 40VDC and expected output is 70V DC to 150V DC variable using program controlled power supply technique. Please let me know if this is practical in case of boost converter using LM5156.

Your guidance on this would be highly appreciated.

Thanks & Regards

Aditya Mene

0 Mounika Girish 2 months ago in reply to ADITYA MENE

TI__Intellectual 2426 points

Hi Aditya,

Just to clarify, The output needs to be adjustable from 70V to 150V and not 0V to 150V right?

Best regards,

Mounika

0 ADITYA MENE 2 months ago in reply to Mounika Girish

Prodigy 60 points

Hi Mounika,

As I have mentioned earlier output needs to be adjustable from 70V to 150V and not 0V to 150V.

Your guidance on this would be highly appreciated.

Thanks & Regards

Aditya Mene

0 Mounika Girish 2 months ago in reply to ADITYA MENE

TI__Intellectual 2426 points

Hi Aditya,

Please also help with the output current needed.

Adding a ref. design with LM5155 device - https://www.ti.com/tool/PMP21629 and https://www.ti.com/tool/PMP21781

Best regards,

Mounika

0 ADITYA MENE 2 months ago in reply to Mounika Girish

Prodigy 60 points

Hi Mounika mam,

The Current requirement for my application is 1 A 150 W output power.

Thanks & Regards,

Aditya Mene

+1 Mounika Girish 2 months ago in reply to ADITYA MENE

TI__Intellectual 2426 points

Hi Aditya,

There is no concern on LM5155 for this specifications mentioned

18V DC to 40VDC and expected output is 70V DC to 150V DC , 1 A 150 W output power

Best regards,

Mounika

+1 ADITYA MENE 2 months ago in reply to Mounika Girish

Prodigy 60 points

Hi Mounika Mam,

Thank you for your valuable support.

It’s great to know that there are no concerns with using the LM5155 for the specified input range of 18 V to 40 V DC and the expected output of 70 V to 150 V DC at 1 A (150 W). Your guidance is much appreciated.

If you're open to it, I’d be glad to connect on LinkedIn or any other platform you prefer to stay in touch and continue learning from your insights.

Thanks & Regards

Aditya

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LM5156: LM5156