15V split rail supply design recommendation

Gergo Santha

Other Parts Discussed in Thread: REF102, TPS54060, TPS54060EVM-590

Hi!

In my recent design I'd like to use an inverted REF102 to get a -10V reference to an MDAC. There would be an I/V converter step after the MDAC, too. In the same design there would be a digital circuitry drawing maximum 50mA current at regulated 3.3V and I also need a low current 5V regulated source to supply an USB-Serial bridge chip. The main power source would be a 24V wall adapter. In summary:

+/- 15V clean rails
+5V for USB-serial bridge
+3.3V for MCU, LCD display w/ backlight etc

For the inverting step I found this note which looks promising: link. However, I'd welcome any recommendations in the first steps as there are lots of possible ways to create such a power supply environment. Thank you!

over 12 years ago

0 Chris Glaser over 12 years ago

TI__Guru*** 147670 points

Here's one better than that link: http://www.ti.com/tool/tps54060evm-590 and http://www.ti.com/lit/an/slva369/slva369.pdf

That's a design for a +/-15V supply that even has an EVM for you to test on. If you need it cleaner, you can use LDOs off the +/-18V that the EVM puts out.

I would recommend re-using the TPS54060 to get 5V from 24V and then using a switcher or LDO to go from 5V to 3.3V. You can find suitable devices at power.ti.com.

0 Gergo Santha over 12 years ago in reply to Chris Glaser

Genius 3585 points

Hi Chris,

thank you for the great advice. I ordered the EVM yesterday. By the way, are the Gerbers publicly available? I'm considering to keep the psu board external.