28v power supply design

[honnaraj.t]

Hi,
I want to design a DC-DC converter to get 5V from 28V(DC). The following are requirement has to match

1) The unit should operate with a power supply with a nominal voltage of 28V.
2) The unit should operate correctly in the input voltage range of +16V DC to +31.5V DC
3) The unit should functional when the power supply voltage drops to 12V DC for few seconds i.e 50ms

questions:
1) How do i provide a single solution which satisfies all these requirements.
2) kindly provide supporting document or link

Thanks in advance.

rds
honnaraj

 

[Dan Mills]

You forgot the second most important number in power supply design (how much current), but I would hit TI and linear tech to see who has something suitable for a buck converter at whatever current you need.

TIs 'webbench' tool will do almost all of the work for you.

as 5V is very much less then 12V, I dont see an issue with extending the operating range down to 12V so the hold up requirement goes away (and down to 8V or so should be doable).

Unless you need more then a few amps, this is trivial to solve.

73 Dan.

 

[KlausST]

Hi.

IC manufacturers help you:
https://www.linear.com/products/step-down_(buck)_regulators

Its just an example of one manufacturer, there are many others....
You will also find datasheets and application notes.


Klaus

 

[colin55]

This DC to DC converter is available on eBay for about $10.00 I think it is 1.5 amp