Frequency divider

A frequency divider is an electronic circuit that divides an input frequency in a specific, almost always integral or rational division ratio. The output waveform can be symmetrical or asymmetrical. The input signal is often a square wave signal, but also sinusoidal and other input signals are possible.

Operation

Frequency division can be based on different principles. There are both analog and digital frequency divider. Options include counting circuits (for example, ring counter ) and PLL circuits.

To construct a very simple synchronous frequency divider for rectangular signals can be used cycles or edge-triggered flip-flops. A simple flip-flop divides by 2

For use as a frequency divider, there are special electronic circuitry, counters. The division is always an integer, preferably in multiples of 2 or 10 levels. One differentiates between synchronous and Asynchronzählern counters. Another possibility are so-called machines.

Pure analog frequency dividers are designed as synchronized oscillators. They are broadly tuned to the expected frequency and then synchronized by the external, to be divided signal. However, the usable frequency range is comparatively small. An application example is the blocking oscillator.

In addition to electronic methods of frequency division, mechanical, pneumatic, and optical principles are possible.

Application

Electronic frequency dividers are widely used. They are found in digital watches, calculators, radio and television equipment, electronic organs, stepper motors and measuring devices such as frequency counters.

Measuring limits

Standard circuits achieve about 100 MHz (108 Hz), the fastest circuits can work up to about 1011 Hz. The combination of very fast electronics and laser frequency comb means and allows measurements to 1015 Hz

• Electrical circuit