MAX3670 LOOP BANDWIDTH CALCULATOR

  Loop bandwidth  (K)   kHz  Required
  VCO Gain (KVCO)   kHz/V  Required
  Phase Detector Gain(KPD) µA/UI
  Predivider (N1)  
  Gain Logic Divider (N2)  
 
  Results Jumper Settings  
  Higher Order Pole Frequency (fHOP)***  kHz     GSEL1 GSEL2 GSEL3  
  Zero Frequency (fZERO)****  Hz              
 
  Components
  C1    pF   RSEL VSEL  
  R1    kΩ      
  C3    pF
  R3*    Ω Required
  C2**    µF
 
 
 
Instructions:
Enter a value in the Loop Bandwidth input box (default is 10).
Enter a value in the VCO Gain input box (default is 124.416).
Select a value from the Phase Detector drop-down box (default is 20).
Select a value from the Predivider drop-down box (default is 8).
Select a value from the Gain Logic Divider drop-down box (default is 1).
Enter a value in the R3 input box (default is 332).
Press the calculate button to compute your results.
* R3 should not exceed 1kΩ because of the op-amps inability to drive large loads.

** C2 is only nescessary if R1 is over 500kΩ. It will filter noise from the charge pump and prevent clipping in the op amp.

*** The higher order pole is recommended to be 4*K to reduce pole interference.

**** The zero frequency is recommended to be 100 time less than K to reduce peaking in the transfer response.