Design of Linear Feedback Shift Register for Low Power Applications

This paper presents the design & implementation of the Linear Feedback Shift Register (LFSR) using the Mentor Graphics tool in 90nm technology. LFSR’s have a wide variety of applications. They are used in pseudo-random variety generation, whitening sequences and pseudo-noise sequences. MOS current-mode logic (MCML) and Dynamic current-mode logic (DYCML) are employed to design an LFSR. MCML is widely used in high-speed applications and these MCML circuits are based on current steering logic. The advantages of the MCML method are that they have high noise immunity due to their differential nature of inputs. The disadvantage of MCML approach is static power dissipation. To overcome these issues of MCML logic, Dynamic CML logic is used. Its advantages include low static power dissipation and high performance. This paper shows the comparison results of CMOS, Dynamic CML and MCML designs in terms of delay, power and transistor count.