Isolated DC-DC converter from 3.3V to 24V @ 4-20mA

Emilija Zukauskaite

Other Parts Discussed in Thread: LM3481, LM5001, TLV61046, TPS61170

Hi,

Please advice what IC I could use for my application as Webench tool doesn't show any results. Vin is 3.3V to 4.2V and Vout is 24V 4-20mA. The output must be isolated.

Thanks!

Emilija

over 5 years ago

0 Ambreesh Tripathi over 5 years ago

TI__Expert 6860 points

Emilija,

You should be able to use LM3481 device for this application .

---Ambreesh

0 Emilija Zukauskaite over 5 years ago in reply to Ambreesh Tripathi

Expert 1100 points

Hi Ambreesh,

LM3481 doesn't work using webench. I get a message "Your preferred device does not work with the inputs you selected.". Have you got any more suggestions?

Thank you.

Emilija

0 Ambreesh Tripathi over 5 years ago in reply to Emilija Zukauskaite

TI__Expert 6860 points

Emilija,

I was able to simulate the same using LM3481 .

---Ambreesh

0 Emilija Zukauskaite over 5 years ago in reply to Ambreesh Tripathi

Expert 1100 points

Hi Ambreesh,

I tried again and it says design cannot be created with the inputs your selected! I tried selecting LM3481 Boost or flyback version from the drop down menu. And I used the same inputs you tried. I really dont know what I'm doing wrong.

Thank you.

Emilija

0 Emilija Zukauskaite over 5 years ago in reply to Emilija Zukauskaite

Expert 1100 points

Hi Ambreesh,

Have you got a simpler solution for my application using less external components? I'm more concerned about the space and the cost rather than the efficiency.

Thank you.
Emilija

0 Ambreesh Tripathi over 5 years ago in reply to Emilija Zukauskaite

TI__Expert 6860 points

Emilija,

I am forwarding your request to the Boost team . They may have low input voltage capable integrated FET boost converter that can be configured as flyback design .

--Ambreesh

0 Garrett Roecker over 5 years ago in reply to Emilija Zukauskaite

TI__Mastermind 21720 points

Hi Emilija,

Is the input voltage of 3.3V fixed? If not please provide the range of the input voltage.
Also is there any desired switching frequency?

Please take a look at the LM5001. This reference design show how to configure the LM5001 as a flyback
http://www.ti.com/tool/PMP7902

Thanks,

Garrett

0 Helen chen over 5 years ago

TI__Mastermind 40080 points

Dear Sir,

Please take a look at TLV61046, it can just meet your requirement. And it has load disconnect function.

0 Emilija Zukauskaite over 5 years ago in reply to Garrett Roecker

Expert 1100 points

Hi Gareth,

The input range is from 3.3V to 8V. There is no requirement for switching frequency.

I tried LM5001 but webench didnt work with my requirements.

Thanks,

Emilija

0 Emilija Zukauskaite over 5 years ago in reply to Helen chen

Expert 1100 points

Hi Helen,

I forgot to mention that the input range is 3.3V to 8V.

Also the IC needs to control light loads because its 4-20mA current.

Thanks and Regards,
Emilija

0 Helen chen over 5 years ago in reply to Emilija Zukauskaite

TI__Mastermind 40080 points

Dear Sir,

Thanks for the update, 8V is a little bit too high for the TLV61046. You can consider to use TPS61170, but this part doesn't has load disconnect function.

0 Emilija Zukauskaite over 5 years ago in reply to Helen chen

Expert 1100 points

Hi Helen,

Will TPS61170 work even Webench doesn't simulate?

Thanks and Regards,
Emilija

0 Helen chen over 5 years ago in reply to Emilija Zukauskaite

TI__Mastermind 40080 points

Hi Emilija,

It could support 3.3Vin/24V output. you can apply for a TPS61170 EVM board to test it.

0 Emilija Zukauskaite over 5 years ago in reply to Helen chen

Expert 1100 points

Thank you, Helen.

0 Helen chen over 5 years ago in reply to Emilija Zukauskaite

TI__Mastermind 40080 points

You're welcome, good luck!

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Isolated DC-DC converter from 3.3V to 24V @ 4-20mA