# Breakpoint frequency

1. Nov 10, 2005

### Midas_Touch

How do I derive the equation of the breakpoint frequency f = 1/2*pi*R*C for a high active filter and a low active filter? Do I use Vin/Vout?

R= resistance
C = Capacitance
Vin = Voltage input
Vout = Voltage output

2. Nov 10, 2005

### SGT

The breakpoint is the frequency where the reactive impedance $$j2\pi fC$$is equal in absolute value to the real impedance R.