Title :
Body-Driven Enhanced-Impedance Current Source: An Approach to the Implementation of Low-Voltage Current-Steering D/A Converters
Author :
Hokmabadi, S. Moslem ; Zabihian, S. Alireza ; Lotfi, Reza
Author_Institution :
Ferdowsi Univ. of Mashhad, Mashhad
Abstract :
Regular Current-Steering D/A Converters (CS-DACs) using high-swing cascode current-source structures fail to operate with very-low supply voltages. In this paper, body-driven enhanced-impedance current cells have been employed to satisfy required characteristics of CS-DAC in low headroom voltage. In this technique, a body-driven amplifier increases the output impedance of a cascode current source without degrading its high-frequency behavior. A 1-V 10-bit 100MHz CS-DAC using the proposed current source structure has been designed and simulated in a 0.18um CMOS technology. Monte-Carlo simulations show that the probability of Spurious Free Dynamic Range (SFDR) of more than 60 dB is more than 90% for input frequencies up to Nyquist frequency, which confirms the proper operation of the converter in very low supply voltages.
Keywords :
CMOS integrated circuits; Monte Carlo methods; digital-analogue conversion; low-power electronics; CMOS technology; CS DAC; D/A converters; Monte Carlo simulations; body driven enhanced impedance current source; cascode current source; headroom voltage; high frequency behavior; low voltage current steering; output impedance; size 0.18 mum; spurious free dynamic range; voltage 1 V; Analog-digital conversion; CMOS digital integrated circuits; CMOS technology; Degradation; Dynamic range; Frequency conversion; Impedance; Low voltage; Signal resolution; Threshold voltage;
Conference_Titel :
Electronics, Circuits and Systems, 2007. ICECS 2007. 14th IEEE International Conference on
Conference_Location :
Marrakech
Print_ISBN :
978-1-4244-1377-5
Electronic_ISBN :
978-1-4244-1378-2
DOI :
10.1109/ICECS.2007.4511198
