25-09-2010, 05:13 AM
Coba kita hitung, jika RZmirror (imp. kolektor-emitor) current source = 100k, VCC = 42 VDC, Vmref (voltase referensi mirror basis) = 5.6V (sesuai zener), berapa Rctl_mirror (r emitor Tr mirror)?
RZmirror = ((Vmref - VBE) x RZmirror) / (VCC - (Vmref - VBE))
>>> Asumsikan TR berbahan silikon, VBE = 0.6V
Maka:
RZmirror = ((5.6 - 0.6) x 100000) / (42 - (5.6 - 0.6)) =~ 13513 Ohm =~ 13.5 k-Ohm
Seharusnya R 10 k di emitor BC546/BC556 mirror itu pakai R pendekatan 12 K diseri 1.5 K...
RZmirror = ((Vmref - VBE) x RZmirror) / (VCC - (Vmref - VBE))
>>> Asumsikan TR berbahan silikon, VBE = 0.6V
Maka:
RZmirror = ((5.6 - 0.6) x 100000) / (42 - (5.6 - 0.6)) =~ 13513 Ohm =~ 13.5 k-Ohm
Seharusnya R 10 k di emitor BC546/BC556 mirror itu pakai R pendekatan 12 K diseri 1.5 K...