A current-mode tunable low-supply-voltage ring oscillator

✍ Scribed by Minglin Ma; Chunhua Wang

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 888 KB
• Volume: 20
• Category: Article
• ISSN: 1096-4290
• DOI: 10.1002/mmce.20470

✦ Synopsis

A new circuit topology using a current-mode low-pass filter for sinusoids has been presented. The technique is relatively simple, in the proposed circuit, only three identical current-mode low-pass filters are connected to each other to realize the small signal path. No external passive components are required except for three capacitors. When compared with LC oscillators, the die area of this work, without inductors, is much smaller. When compared with voltage-mode ring oscillators, the supply voltage of this work is much lower. As a particular example, a 2.4 GHz, 1.2-V power supply, 5-mW sinusoidal oscillator is demonstrated. The oscillation frequency is tuned by the value of that three capacitors, over $900 MHz, and the tuning range is 37.5%. The phase noise results in À94 and À120 dBc/Hz at 1 and 10 MHz from the carrier, respectively. V