Output Impedance and Termination of Zero Delay Buffers | Cypress Semiconductor
Output Impedance and Termination of Zero Delay Buffers
The output impedance of Cypress Zero Delay Buffers is between 20-30 ohm, unless otherwise specified in the datasheets. So its recommended to use a 20-30 ohm series resistor to match a 50 ohm transmission line. Since the output impedance for the ZDBs is between 20-30 ohm, it is recommended to start with (X-28) Ohms series termination placed as close as possible to each output pin (where X is the transmission line impedance you connect to), thus assuming a 28 Ohms output impedance initially. So if you connect the output to 50 Ohms, then 50-28=22 Ohms series termination will be required for impedance matching.