Phase detectors are an integral part of electronic circuits due to the purpose they serve. In principle, a phase detector is used to generate an output voltage that is directly related to the phase difference between two varied signals.

Phase detectors are crucial to the operation of a phase-locked loop. To fully understand the significance of a phase detector, you’ll need to understand how a phase locked loop works. However, just to give you an idea, this circuit is used in every radio communication system.

A phase detector is the name of a circuit, but the truth is that a lot of different electronic circuits can be designed to work as a phase detector. However, these are the two most common types of phase detector: phase sensitive detector, phase-frequency sensitive detector.

Phase Sensitive Detector

This is the simplest configuration of a phase detector as the name suggests, this type of circuit is only sensitive to the phase of the input signal. The phase sensitive detector can only detect the phase difference between the two relayed signals.

It’s also worth mentioning that while one signal comes from the source, the other is supplied through a Voltage Controlled Oscillator. After phase detection, a directly proportional voltage is generated.

However, phase sensitive detector is not your best option if you’re looking to generate a constant voltage. These detectors only generate a constant output voltage if the phase difference is also constant. A constantly changing phase difference means a varying voltage will be generated.

Phase-Frequency Detector

The need for a phase-frequency detector arises from a critical flaw in the phase sensitive detector. Since the phase sensitive detector is responsible for generating a voltage proportional to the phase difference, this can lead to the generation of AC voltage in an out-of-lock circuit.

In a phase sensitive detector, the voltage can continue to rise and burn out other circuit components!

However, phase-frequency detectors overcome this flaw by producing a proportional voltage to phase difference but only if it’s within the ±180° range. Once the phase difference exceeds these limits, the voltage is limited to the positive or negative extreme as well.

This ensures that the circuit elements are safe and alarmingly high voltage isn’t generated. Phase-frequency detector’s ability to detect when the phase difference is ± 180° is also why it’s also sensitive to the frequency as well as the phase.

Phase detectors are essential components in circuits of many hardware designs. If you’re looking for a reliable and high-quality phase detector as well, get in touch with ADSANTEC!

We have a huge assortment of ultra-high speed and high-frequency chips including clock splitter, active phase shifter, active power divider, and so much more! Get in touch now to make sure that your circuit’s physical implementation goes according to plan!