Hi team,
My customer measured Vout ripple on LM61460EVM-AS-400K. Could you check and comment for each condition 1 and 2? I'd like to know that these waveforms are normal or not.
Condition.1
Vin=24V
Vout=3.308V (Rfbt=300kohm, Rfbb=130kohm)
Fsw=490kHz (Rrt=27kohm)
Iout=0A to 6A (24v-0A in the file means output current is 0A)
/cfs-file/__key/communityserver-discussions-components-files/196/LM61460EVM-Vout-ripple.zip
Looking at the zoomed waveform, the output ripple voltage does not seem to be normal. Have you seen similar Vout ripple on the LM61460EVM? Is that normal operation?
Customer modified the L, Cout, and Vout value on condition.2. Could you also check the Vout ripple voltage waveforms in the below link? In the zoomed waveform of 24 V, the ripple voltage contains a square wave, which seems to be an effect of Cout ESL.
Condition.2
Vin=24V / 7V
Vout=3.375V (Rfbt=285kohm, Rfbb=120kohm)
Iout=0A to 6A
L=3.3uH (1267AY-3R3N)
Cout=added 22uF as CO5, so total cout=22uFx5=110uF
Fsw=490kHz (Rrt=27kohm)
Customer added 22uF(CO5) in the red circle.
Regards,
Yamaguchi