Frequency Synthesizers ICs
Frequency synthesizers ICs (Integrated Circuits) are electronic circuits that are used to generate a stable and accurate output frequency signal from a reference frequency input signal.
These ICs are widely used in various electronic systems such as wireless communication systems, radar systems, and test and measurement instruments.
The basic operation of a frequency synthesizer IC involves generating a series of harmonic signals from a reference frequency using a frequency multiplier or divider circuit. These harmonic signals are then mixed with another signal generated by a voltage-controlled oscillator (VCO) to produce the desired output frequency.
The output frequency can be controlled by varying the frequency of the VCO with a control voltage provided by an external source or a built-in frequency control circuit.
There are various types of frequency synthesizer ICs available in the market, including analog and digital frequency synthesizers. Analog frequency synthesizers use analog components such as mixers, amplifiers, and filters to generate the output frequency signal. They offer high performance in terms of phase noise and spurious signals but are relatively complex and expensive to implement.
Digital frequency synthesizers, on the other hand, use digital signal processing techniques to generate the output frequency signal. They offer high accuracy and flexibility in terms of frequency resolution and tuning range and are relatively easy to implement. However, they suffer from higher phase noise and spurious signals compared to analog frequency synthesizers.
The Most Popular Frequency Synthesizers IC
There are many popular frequency synthesizer ICs available in the market, here are a few examples:
1.Analog Devices AD9959: This IC is a high-speed DDS (direct digital synthesizer) with a 14-bit DAC and a maximum output frequency of 500 MHz.
2.Texas Instruments CD4046B: This is a low-power CMOS IC that can be used as a phase-locked loop (PLL) or a frequency synthesizer. It has a maximum frequency range of 1 Hz to 40 kHz.
3.Silicon Labs Si5351A/B/C: This is a low-jitter clock generator IC that can generate up to 3 different frequencies simultaneously. It can be programmed using an I2C interface and has a maximum frequency of 200 MHz.
4.Maxim Integrated MAX2870: This is a fractional-N PLL frequency synthesizer with an integrated VCO. It has a maximum frequency of 13.6 GHz and can be programmed using a SPI interface.
5.National Semiconductor LM565/LM566: These are general-purpose PLLs that can be used as frequency synthesizers, tone decoders, or FM demodulators. They have a maximum frequency range of 0.001 Hz to 500 kHz.
6.Analog Devices ADF4350/ADF4351: These are high-performance fractional-N synthesizers with a maximum frequency of 4.4 GHz. They can be programmed using a SPI interface.
7.Texas Instruments LMX2594/LMX2595: These are ultra-low-noise synthesizers with a maximum frequency of 15 GHz. They have an integrated VCO and can be programmed using a SPI interface.
8.These are just a few examples of popular frequency synthesizer ICs. The choice of IC depends on the specific application requirements such as frequency range, resolution, phase noise, power consumption, and interface compatibility.