Integer-N PLL/Synthesizer Suppresses System Noise

The LTC6945 6-GHz, integer-N frequency synthesizer specifies a normalized closed-loop in-band phase noise of -226 dBc/Hz and a normalized in-band 1/f noise of -274 dBc/Hz. Wideband phase noise floor is -157 dBc/Hz and spurious output is -102 dBc. In a typical 900-MHz application, the device enables a closed-loop phase noise of -100 dBc/Hz at 1-kHz offset. The LTC6945 is designed to work in conjunction with an external low noise VCO up to 6 GHz. In addition, the device has an on-chip output divider that is programmable from 1 through 6 to extend the tuning frequency coverage to as low as 350MHz. Available in a 4 mm x 5 mm, 28-lead plastic QFN package, price starts at $4.95 each/1,000. LINEAR TECHNOLOGY CORP., Milpitas, CA. (800) 454-6327.