Calibration of Cyclic-Pipelined ADCs Using CMOS for Area-Efficiency

Wael Saad Ahmed 1, *, Zahraa mehssen agheeb 2 and Walead kaled sleaman 1

1 Faculty of Medicine, Tikrit University, Salahaddin, Iraq.
2 Department of Electrical Engineering, University of Misan, Iraq.
 
Research Article
Global Journal of Engineering and Technology Advances, 2023, 15(03), 008–016.
Article DOI: 10.30574/gjeta.2023.15.3.0104
Publication history: 
Received on 06 April 2023; revised on 01 June 2023; accepted on 03 June 2023
 
Abstract: 
One of the principal obstacles in the development of pipeline analog-to-digital converters (ADCs) is the imprecision associated with residue amplification. Operational amplifiers (Op-Amps) that possess high gain and speed are recognized for their excessive power consumption, making them unsuitable for employment in proficient analog-to-digital converters (ADCs). The study presents a new method for foreground calibration that addresses amplification differences in cyclic-pipelined ADCs, reducing the need for internal amplifier DC gain. The calibration technique was applied to a cyclic-pipelined ADC with a sampling rate of 2 MS/s and 16-bit resolution. The design of this ADC was optimized for area efficiency, and its fabrication utilized 180 nm CMOS technology. The analog-to-digital converter (ADC) used a 5-bit resolution sub-ADC performing 4 cycles to reduce potential errors. Each cycle contained one bit of redundancy. A fixed-point iterative algorithm was used to find the exact gain for each amplifier. Simulation data shows a SINAD of 100. 6 dB, despite a 57 dB DC gain amplifier. The ADC's active area is 1. 8 mm2 at 30 consumption. 43 mW.
 
Keywords: 
ADC; 180 nm; Pipeline; Convertor; DC gain
 
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