VCO ( 1 IC ) VCO PCB ( IF ) ( VCO ) ( IF ) VCO Maxim IC ( MAX2605 – MAX2609 ) VCO PCB VCO Maxim MAX2605–MAX2609 5 IC 650MHz VCO ( 6mm x10mm VCO 1) VCO 45MHz ( ) IC ( +0.4VDC +2.4VDC ) IC ( PLL ) MAX2605–MAX2609 +2.7VDC +5.5VDC ( 2) IC 6 SOT23 VCC IND 1 6 OUT+ GND 2 5 VCC TUNE 3 4 OUT- OUT MAX2605–MAX2609 2. MAX2605 – MAX2609 PCB TUNE 1. 1 VCO 2000 8 Microwaves & RF 3 VCO IC 6 SOT23 MAX2605 100kHz : 100kHz 150MHz 300MHz 300MHz 500MHz 500MHz 650MHz 45MHz 70MHz -117dBc/Hz 70MHz 150MHz -112dBc/Hz ( MAX2606 ) ; -107dBc/Hz ( MAX2607 ) ; -100dBc/Hz ( MAX2608 ) ; -93dBc/Hz ( MAX2609 ) IC : VCO VCO VCO ( (Q) ) 3 IC VCO ( ) MAX2605–MAX2609 Q MAX2605 Q PNP IC PMOS VCO VCO VCO Maxim MAX2605–MAX2609 VCO Maxim MAX2605 – MAX2609 ( f MAX ( VTUNE ) IC ( fOSC ) ≤ fMIN VTUNE = 2.4V Colpitts ( ) fMIN ) 0.4V IC VCC VCO IC OUT+ IND BIAS LF AMPLITUDE CONTROL TUNE MAX2605–MAX2609 OUT- GND 3. MAX2605 – MAX2609 VCO IC 4 fOSC ≥ fMAX ±2% ( <0.5%) PCB IND SMT VCO VCO L F2 VCO MAX2605–MAX2609 MAX2605 – MAX2609 VCO VCO : ; 1) ( 2) ( fNOM ) VCO 1) ( 5) / 4) IND PLL ( ( OUT- OUT+) ( VCC ) ( LF) ( SMT ) 1.2 LF1 LF2 LF1 Q LF2 L F1 LF – LF1 Q LF2 SMT 20% Q / 3dB OUTV CC OUT- OUT+ OUT+ PCB VCC MAX2608/MAX2609 OUT- OUT+ VCC C2 1 6 OUT+ R2 LF 2 5 R1 TUNE 3 4 OUTC1 FROM PLL LOOP FILTER OUTPUT 4. MAX2605 – MAX2609 VCO IC 5 TO PLL/MIXER THROUGH A RESISTOR OR CAPACITOR DIVIDER NETWORK / MAX2607* REQUIRED INDUCTANCE vs. DESIRED VCO FIXED FREQUENCY 170 MEASUREMENT CONDITIONS VCC = 2.75V, TA = +25°C, RLOAD = 100Ω||50Ω (100Ω RESISTIVE PULLUP PARALLELED WITH 50Ω VNA IMPEDANCE), UNUSED OUTPUT TERMINATED IN 50Ω, PCB PARASITIC SHUNT CAPACITANCE (IND TO GND) = 0.45pF 160 150 THE INDUCTANCE LISTED IS THE PRECISE NOMINAL INDUCTANCE VALVE REQUIRED FROM IND TO GND IN ORDER TO GUARANTEE THE VCO CAN TUNE TO THE DESIRED FIXED FREQUENCY, OVER ALL OPERATING CONDITIONS AND WORST-CASE COMPONENT VALUES (±2% INDUCTOR AND IC PROCESS VARIATION). REQUIRED INDUCTANCE (nH) 140 130 120 110 100 90 EFFECTIVE INDUCTANCE FROM IND TO GND 80 70 60 50 INDUCTOR VALUE MOUNTED ON EV KIT 40 30 150 160 170 180 190 200 *FIGURE FROM MAX2607 DATA SHEET 5. 210 220 230 240 250 260 270 280 290 300 DESIRED VCO FIXED FREQUENCY (MHz) MAX2607 VCO IC ( 150MHz 300MHz ) ( LF ) / VCO MAX2605–MAX2609 MAX2605 – MAX2609 ! Maxim MAX2605–MAX2609 VCO 6 MAX2605 – MAX2609 VCO VCO $0.03