ADG918 RF switch

Question

I bought a ADG918 EVAL board. Here is the configuration: A modulated signal source 72Mhz sent into the RFC pin; 2.75V Vdd voltage; 1Mhz 0~1.5v square wave was in control pin. 
 Schematic: 
 
 Input on RFC pin: modulated 72Mhz 
 
 When power it on, the yellow is the output. 
 Q1: why there is a DC slop when it's off. I placed a capacitor before the input to isolate the DC voltage. 
 
 Q2: Can the input sinwave becomes a +/- sin wave let's say -1.5v to 1.5v peak to peak?

kikuman · Accepted Answer

Hi Simon88 ADG918 is an absorptive switch. So, any unused port is automatically terminated to 50-ohm. If you are measuring at point 2, you shouldn't be seeing any DC offset. Is there anything else connected to 2 when you are taking the plot?)

Electronic Design Services - PartnerZone

Products Mentioned

ADG918 RF switch