Multiphase Oscillator with 40% Spread Spectrum Frequency Modulation and 250Khz Output Frequency
This is a precision, low power, and easy-to-use oscillator that provides multiphase outputs. The output frequency of the project is set to 250Khz, with 40% spread spectrum. The oscillator frequency can be set by resistor R1, and the spread spectrum can be changed using R3. The master oscillator is controlled by the RSET resistor R1 and has a range of 100khz to 20Mhz. In order to accommodate a wider output frequency range, a programable divider, (divide by 1, 10, 100) is included and can be set using jumper J1. The integrated programmable multiphase circuit provides either 2, 3, or 4 phase waveforms. The LTC6902’s SSFM capability modulates the oscillator’s frequency by a pseudorandom noise (PRN) signal to spread the oscillator’s energy over a wide frequency band. This spreading decreases the peak electromagnetic radiation level and improves electromagnetic compatibility (EMC) performance. The amount of frequency spreading is programmable by a single additional external resistor R3 (RMOD). Refer to 4 Phase output waveform diagram.
Multiphase Oscillator with 40% Spread Spectrum Frequency Modulation and 250Khz Output Frequency – [Link]