i'm studying about Phase Frequency Detector (PFD) as a part of Phase Locked Loop (PLL) theory, but after viewing the textbook, i've got some questions.here is the link from which you can download a part of my textbook about PFD:
http://www.mediafire.com/view/?2qst60ke29ci44i
i haven't been clear why we can get equation (2.24) ?
In my opinion, from figure 2.11, ud can get only two value Ub and zero, so the average signal can not get a negative value! However, according to textbook, the opposite's still right ! hope someone can give me an explaination ! ^~^
http://www.mediafire.com/view/?2qst60ke29ci44i
i haven't been clear why we can get equation (2.24) ?
In my opinion, from figure 2.11, ud can get only two value Ub and zero, so the average signal can not get a negative value! However, according to textbook, the opposite's still right ! hope someone can give me an explaination ! ^~^