SBOS746A June 2016 – February 2021 THS6302
THS6302 is a dual-port, very-high-bit-rate linear xDSL, G.Fast, and G.mgFast differential line driver where the device drives a twisted pair cable. The signal is typically generated by a DAC in the DSL ASIC at low signal swings that is amplified by the G.Fast line driver.
The G.Fast system is ac-coupled when transmitting information above the audio band. On the input of the line driver, this ac-coupling translates into the series capacitors to isolate the dc voltage coming from the DAC output common-mode voltage. On the output, a transformer is used to help isolate the 48 V present between the tip and ring of the telephone line.
The transformer can be set to any useful ratio. In practice, the transformer-turn ratio is set between 1:1 and 1:1.4 for the device. Synthetic impedance at the output of the line driver is common in many xDSL applications. However, to support high AC performance needed for typical G.Fast and G.mgFast applications, THS6302 is an internally fixed-gain device and often synthetic impedance configuration is not recommeded to maintain the AC performance.
Note: the resulting load detected by the amplifier may affect the amplifier linearity or output voltage swing capabilities.