The MAX2605-MAX2609 are compact, high-performance intermediate-frequency (IF) voltage-controlled-oscillators (VCOs) designed specifically for demanding portable wireless communication systems. They combine monolithic construction with low-noise, low-power operation in a tiny 6-pin SOT23 package. These low-noise VCOs feature an on-chip varactor and feedback capacitors that eliminate the need for external tuning elements, making the MAX2605-MAX2609 ideal for portable systems.
This application note describes phase-noise measurements performed on these parts, using Maxim Evaluation kits. VCC
= +2.75V, TA
= +25°C, and VTUNE
Note that in each graph presented, the phase noise follows the expect 20dB per decade roll-off. The MAX2607 was not measured for this application note, so a graph was not prepared. Expect the phase noise of the MAX2607 to follow the same roll-off exhibited by all the VCOs in this family.