switching regulator output voltage

Status
Not open for further replies.
Y

yassin.kraouch

Advanced Member level 2
Joined
Jul 5, 2009
Messages
631
Helped
40
Reputation
80
Reaction score
40
Trophy points
1,308
Activity points
5,094
in the picture attached a shematic from a switching regulator, i take this from the manufacturer datasheet, the output is 3V3, what is the resistance that i should change to output 5V ?
 

Attachments

  • reg_switch.png
    30.6 KB · Views: 89

Re: switch regulator output voltage

The ratio of R1 to R2 sets the output voltage. For 5V out, you want R1/R2=3.0486. Any combination of resistances close to this will work fine, but you should keep the values in the range of 1K-100K.
 

Re: switch regulator output voltage

To add to the discussion, you also need to ensure that the L1 choke that the datasheet recommends does not saturate for the new output voltage setting.
My calculations show that there is a small increase in inductor peak current with 5V output compared to the 3.3V output (for same output maximum load current). Also Vin_min will no longer be allowed to be 4.4 V, this being a buck topology.

Regards
 

Re: switch regulator output voltage


the Vin_min that i willl use is 12V
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…