Please explain,How a 180 phase shift occurs in "ce" Amplifier. Change in input voltage leads to change in output voltage is some how I know, but this happen in "cb" Configuration too. When Vbe increases Vce decrease(PNP transistor)

  • \$\begingroup\$ A "change" can be pos. or negative...Open your mind.... \$\endgroup\$
    – LvW
    Commented Nov 4, 2018 at 12:37
  • \$\begingroup\$ @LvW exactly.. That change can be found in CB configuration also \$\endgroup\$ Commented Nov 4, 2018 at 14:17
  • \$\begingroup\$ Are you sure...? Can you explain? \$\endgroup\$
    – LvW
    Commented Nov 4, 2018 at 14:31
  • \$\begingroup\$ @LvW generally during a input signal operation if Veb increase then corresponding ly Vcb increase.. Correct me if it is mistake \$\endgroup\$ Commented Nov 4, 2018 at 15:08
  • 1
    \$\begingroup\$ cos(180 degrees) = -1. Does that help? \$\endgroup\$
    – TimWescott
    Commented Nov 4, 2018 at 16:22

1 Answer 1


The top end of the collector resistor does not move. Thus the bottom end, the output, has to move when the current changes.

But the 2 resistors are used at opposite ends, thus the phase becomes reversed.


simulate this circuit – Schematic created using CircuitLab


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