Does the DS26334 LIU support internal impedance-matched operation? If so, what are the steps to program the device in this mode?
A10. Yes, the DS26334 does support internal impedance-matched operation for devices that are revision A2 or later. Revision A1 does not support this mode. When the DS26334 is in internal impedance-termination mode, RTIP and RRING require no external resistance components. However, for better internal resistance accuracy, a 16.5kΩ ±1% resistor is required on the RESREF pin. For external termination mode, the RESREF pin must be tied to GND. It is also important to note that, in internal impedance-termination mode, a 1:1 transformer on the receive side is required. If you are using a 1:2 transformer, a 30Ω resistor must be placed in parallel with RRTIP and RRING.
