Accurate Tunable‐Gain 1/x Circuit Using Capacitor Charging Scheme. Issue 5 (1st October 2015)

• Record Type: Journal Article
• Authors: Yang, Byung‐Do; Heo, Seo Weon
• Is Part Of: ETRI journal. Volume 37:Issue 5(2015)
• Page Start: 972
• Page End: 978
• Publication Date: 2015-10-01
• Subjects: 1 over x -- analog divider -- process independent -- capacitor charging -- tunable gain; Telecommunication -- Periodicals; Electronics -- Periodicals; Electronics; Telecommunication; Periodicals; Periodicals; 621.38205
• DOI: 10.4218/etrij.15.0114.0577
• Languages: English
• ISSNs: 1225-6463

Abstract

Abstract : This paper proposes an accurate tunable‐gain 1/ x circuit. The output voltage of the 1/ x circuit is generated by using a capacitor charging time that is inversely proportional to the input voltage. The output voltage is independent of the process parameters, because the output voltage depends on the ratios of the capacitors, resistors, and current mirrors. The voltage gain of the 1/ x circuit is tuned by a 10‐bit digital code. The 1/ x circuit was fabricated using a 0.18 μm CMOS process. Its core area is 0.011 mm 2 ( 144 μ m × 78 μ m ), and it consumes 278 μW at V DD = 1.8 V and f CLK = 1 MHz . Its error is within 1.7% at V IN = 0.05 V to 1 V.