Differential line driver

摘要

A differential line driver with 4X supply voltage swing with a 1:1 transformer, which enhances the loop length for applications such as digital subscriber line includes: a differential circuit having first and second input nodes, first and second output nodes 52 and 54, and a supply voltage node; a transformer 22 having a first coil coupled between the first and second output nodes; and a center tap 50 of the first coil coupled to the supply voltage node. The device also acts as an active impedance termination, which eliminates the series termination resistor in conventional hybrids and thereby saving 6dB transmit power. <IMAGE>