This application note helps customers choose between the CS61575 and CS61574A. Both the CS61575 and CS61574A are pin-compatible, higher performance alternatives to the CS61574. Performance improvements include a reduction in power requirements by 50%, a guarantee of 14 dB of transmitter return loss, and an optional B8ZS/AMI/HDB3 coder. Both the CS61575 and CS61574A provide all these advantages, and differ only in the areas of receiver jitter transfer function and receiver propagation delay.