The 8T49N4811 is a highly flexible FemtoClock® NG pin-programmable clock generator suitable for networking and communications applications. It can generate five different output frequencies with multiple copies of each. A fundamental mode crystal, single-ended, or differential input reference may be used as the source for the output frequency. The use of pin programming to select the input source/frequency, desired output frequencies, and output styles allows a single device to be used in a wide variety of applications without the need for register programming. Selection pins use 3-level options to maximize flexibility while minimizing package size. Selection is performed by tying a selection pin high or low or by leaving it floating, eliminating the need for passive components to drive a desired logic level.