Speakerguy
Active Member
Hey guys,
General question here. I was watching an Analog Devices web seminar the other day and they talked about power supply filtering of a switching power supply followed by a standard linear regulator (LM7805). They mentioned that a choke in series with the voltage output of the 7805 (after the output capacitors) helped dramatically in their application.
Question: how do I go about selecting the value of the choke, and do I want to put any bulk electrolytics after it (pi filter)? The ripple rejection of linear regs seems to be pretty poor above 100KHz which is where most switchers operate.
Thanks!
General question here. I was watching an Analog Devices web seminar the other day and they talked about power supply filtering of a switching power supply followed by a standard linear regulator (LM7805). They mentioned that a choke in series with the voltage output of the 7805 (after the output capacitors) helped dramatically in their application.
Question: how do I go about selecting the value of the choke, and do I want to put any bulk electrolytics after it (pi filter)? The ripple rejection of linear regs seems to be pretty poor above 100KHz which is where most switchers operate.
Thanks!