# Why parallel diodes on the output of a switch-mode?

I am looking at buck-boost converters on the Texas Instruments design tool, and multiple of these topologies have parallel diodes on the output. I cannot see any reason to do this.

Can anyone explain the purpose of paralleling D4 and D2 on the output?

• Current sharing can be a problem but usually these two diodes are on a single die so we can expect a decent sharing between the two dice: a) they are at the same operating temperature and b) their $V_f$ are probably quite close as they come from the same wafer lot. I've seen that in many hi-volume adapter designs and even paralleled diodes bridges sometime! – Verbal Kint Sep 2 at 17:03