some questions about ADF5901 and ADF4159


i use ADF5901 with ADF4159. But i have two questions about ADF5901. 

1. Does the output power of TX out of ADF5901 can be changed from -20dBm to +8dBm  by change the Tx AMP CAL REF CODE? i connect a amplifier after ADF5901. So I should check this.

2. I think the VCO-CAL  in ADF5901 is useless  when  i use ADF4159 to control the Vtune of VCO in ADF5901. So i want to know how do i set the N-Divider and R-Divider in ADF5901?  

 Because in a PLL,the  N-divider and R-divider i really use is  in PLL just the ADF4159 but not in VCO just the ADF5901.

look forward for your reply.

  • As you can read from the previous response by pwalsh, REFin is needed for VCO calibration and initialization on the ADF5901 to ensure the VCO is centered in the band of operation. As per ADF5901 datasheet, REFin frequency range is 10MHz min. and 260MHz max. As said, REFin is for VCO_CAL which is to make sure the right frequency. It is not related to the TX output power. TX output power is controlled by using TX_AMP_CAL_REF_CODE