591BD125M000DG

Oscillators

Oscillators are devices or circuits that generate a sine wave at a specific frequency and amplitude. Oscillators are usually used in applications such as signal generation and regulation. In many cases, they also provide a timing reference for synchronizing electronic equipment. 591BD125M000DG is a type of oscillator.

591BD125M000DG Application Field

The 591BD125M000DG is a Voltage Controlled Oscillator (VCO) designed for use in Ultra Low Power (ULP) applications such as Radio Frequency Identification (RFID) and wireless technology. This oscillator is designed to operate from 3.0V to 5.5V. It provides a wide, pin selectable, output frequency range of 125MHz to 1000MHz in 4 selectable kHz steps. Other features of the 591BD125M000DG include low current consumption, approximately 150nA, aiding in ULP operation and wide temperature range operation.

591BD125M000DG Working Principle

The 591BD125M000DG is a closed loop frequency synthesizer where the voltage supplied to the device sets the oscillator frequency. A voltage controlled oscillator (VCO) is used for the frequency synthesis, and a Phase Locked Loop (PLL) is used to make the oscillator accurately follow the input voltage. The PLL is composed of an analog control loop and a digital loop, which is implemented in a digital signal processor (DSP) integrated circuit (IC).

The analog control loop is composed of the VCO, the maximum frequency divider, the phase/frequency comparator, and the low pass filter. The VCO is a CMOS oscillator with an adjustment range of 125MHz to 1000MHz. The output of the VCO is fed to the maximum frequency divider, which divides the frequency into 16 parts. The output of the divider is compared with the reference frequency (generated by the DSP) in a phase/frequency comparator, and the difference (error signal) is fed to the low pass filter to remove high frequency components. The low pass filter output voltage is applied to the VCO to control its frequency.

The digital loop consists of the DSP IC which is programmed with an algorithm to adjust the reference frequency according to the control voltage. The control voltage is fed to a DAC that converts it into digital signals, which are processed by the DSP IC to generate the reference frequency. The reference frequency is then sent to the phase/frequency comparator in the analog loop to compare with the output of the 10MHz divider.

Conclusion

The 591BD125M000DG oscillator is designed to provide a wide, pin selectable, output frequency range of 125MHz to 1000MHz in 4 selectable kHz steps, suitable for use in Ultra Low Power (ULP) applications. The oscillator is a closed loop system using a VCO and PLL as a frequency synthesizer, composed of an analog control loop and a digital loop.