What is the output/input impedance value of CC2xxx?

Jacktang

What is the output/input impedance value of CC2xxx? [Copy link]

For single-ended output/input, we can consider 50 Ohm. For double-ended differential ports, such as CC253x and CC254x, the differential impedance is a non-standard value. TI recommends copying the reference design instead of telling the specific impedance value due to the following considerations.

First, the RF output/input impedance of differential port chips such as CC253x and CC254x is not the standard 50 Ohm or 100 Ohm.

Second, it is not practical to tell the differential impedance. Because the simulation parameters during chip design are different from the actual ones, the reference design is determined by TI engineers after a lot of debugging and testing based on the simulation parameters.

Third, because the parasitic RF parameters on the board have a relatively large impact on the differential impedance, if the line width and line spacing calculated by the impedance calculation tool are used, the effect will be far worse. It is still necessary to debug the impedance matching on the board.

Finally, the actual routing strictly requires the use of distributed parameters to be rigorously described. In addition, if the impedance is told, it is still impossible to strictly control it due to the parasitic parameters of the routing and devices on the circuit board.

Because of the above reasons, strict reference design becomes the most feasible, simplest and most effective method.

alan000345

Good knowledge.