Q
I´m using the spice model of the ADG884. In the datasheet the -3dB Bandwidth is18MHz. In the simulation the result is about 1.7GHz. Is the analog bandwidth of
the signal chain not contained in the Spice model?
A
The SPICE Model of ADG884 contains correct bandwidth value. The simulation ofbandwidth is not possible with a AC sweep simulation. Please have a look at
attachment.
For bandwidth simulation a network analyzer is needed. I simulated in MultiSim
12.0 with Network analyzer XNA1 of Agilent. It matches input and output with a
50 Ohm resistor.
The simulation result is very precise. The S-Parameter s21 shows Vout/Vin. At
-3dB amplitude decrease (upper chart, page 2), or at -45° phaseshift (lower
chart, page 2)you have a frequency of about 18 MHz.
The attached measurement shows at -45.134° phase shift a frequency/bandwidth of
17.78MHz.
