Analog voltage comparator based on digital differential circuit

This paper proposes an innovative, digital-in-concept prospective idea for designing smart analog circuits, operated on low voltage. The mixed signal circuit consists of both digital and analog circuit in which the CMOS digital circuit is easier to fabricate and it increases the speed of the circuit as most of the delay in the circuit comes from the analog circuitry. In present work digitally enhanced analog voltage comparator has been designed using a pure digital differential circuit technique. The proposed digitally enhanced analog voltage comparator circuit has low power dissipation of 0.324μW, high resolution of 1.96 mV, low DC offset of 1 mV, full output swing of 0-1.8V and common mode input range of 0-1.8V. The digital differential circuit has been connected in the unity gain configuration to prove the concept of proposed circuit. The circuit has been simulated using SPICE in TSMC 0.18μm CMOS technology at 1.8 V with load capacitance of 1pf.

[1]  R. S. Gamad,et al.  Design of Low Power and High Speed CMOS Comparator for A/D Converter Application , 2012 .

[2]  Edinei Santin,et al.  A Two-Stage Fully Differential Inverter-Based Self-Biased CMOS Amplifier With High Efficiency , 2011, IEEE Transactions on Circuits and Systems I: Regular Papers.

[3]  Germano Nicollini,et al.  A 1 W 104 dB SNR Filter-Less Fully-Digital Open-Loop Class D Audio Amplifier With EMI Reduction , 2012, IEEE Journal of Solid-State Circuits.

[4]  Harish M. Kittur,et al.  A 180nm CMOS Low Power Latched Comparator for NMR Applications , 2012 .

[5]  Sudhanshu Shekhar Jamuar,et al.  Low voltage analog circuit design techniques , 2002 .

[6]  K. E. Kuijk,et al.  A precision reference voltage source , 1973 .

[7]  Geng Yang,et al.  The Design of All-Digital Polar Transmitter Based on ADPLL and Phase Synchronized ΔΣ Modulator , 2012, IEEE Journal of Solid-State Circuits.

[8]  P.R. Gray,et al.  MOS operational amplifier design-a tutorial overview , 1982, IEEE Journal of Solid-State Circuits.

[9]  Mohamed I. Elmasry,et al.  MOS current mode circuits: analysis, design, and variability , 2005, IEEE Transactions on Very Large Scale Integration (VLSI) Systems.

[10]  Francesco Centurelli,et al.  A very low-voltage differential amplifier for opamp design , 2011, 2011 20th European Conference on Circuit Theory and Design (ECCTD).

[11]  O. Moreira-Tamayo,et al.  All-digital TX frequency synthesizer and discrete-time receiver for Bluetooth radio in 130-nm CMOS , 2004, IEEE Journal of Solid-State Circuits.

[12]  Ian Galton,et al.  A digital common-mode rejection technique for differential analog-to-digital conversion , 2001 .