A pseudo differential Gm - C complex filter with frequency tuning for IEEE802.15.4 applications

作者：Cheng Xin^*; Zhong Lungui; Yang Haigang; Liu Fei; Gao Tongqiang

来源：Chinese Journal of Semiconductors, 2011, 32(7).

DOI：10.1088/1674-4926/32/7/075005

• Center frequency
• CMOS processs
• Common mode
• Common mode feedback
• Complex filters
• Feed-Forward
• Frequency-tuning
• GmC filter
• Group delay ripples
• IEEE 802.15.4
• IEEE 802.15.4 standards
• In-band
• Low-IF receivers
• Measurement results
• Nonideality
• Power supply
• Pseudo differential
• Re-configurable

This paper presents a CMOS Gm - C complex filter for a low-IF receiver of the IEEE 802.15.4 standard. A pseudo differential OTA with reconfigurable common mode feedback and common mode feed-forward is proposed as well as the frequency tuning method based on a relaxation oscillator. A detailed analysis of non-ideality of the OTA and the frequency tuning method is elaborated. The analysis and measurement results have shown that the center frequency of the complex filter could be tuned accurately. The chip was fabricated in a standard 0.35 μm CMOS process, with a single 3.3 V power supply. The filter consumes 2.1mA current, has a measured in-band group delay ripple of less than 0.16 μs and an IRR larger than 28 dB at 2 MHz apart, which could meet the requirements oftheIEEE802.15.4 standard.

• 出版日期2011