Fully integrated, high performance triple SD PLL (2.2Ghz to 4.4Ghz) with minimized interaction

3 Sigma delta PLLs covering an octave have been integrated on one BiCMOS 0.35 um CSS (channel stacking switch) chip. The 3 PLLs can work simultaneously synthesizing the same frequencies or different frequencies. To minimize the dynamic coupling among the PLLs a complete calibration algorithm has been implemented while to avoid static coupling a large use of differential structure and other design techniques have been used. The maximum composite spurious (due to PLLs coupling, Xtal spurious and fractional spurs) is -35 dBc (in +/-15 MHz range). Each PLL has a frequency range from 2.2 GHz to 4.4 GHz with a worst-case (over process and temperature) integrated rms of 1.2 deg at 3.8 GHz. The frequency step (31.25 KHz) is obtained with a 10 bit SD clocked at 32 MHz. The single PLL draw 35 mA from 3.8 Volt supply (regulated internally to 2.8 or 3.4 Volt) for 3.2 mm
²
.