A 1 GHz Equiripple Low-Pass Filter With a High-Speed Automatic Tuning Scheme
A 1 GHz Equiripple Low-Pass Filter With a High-Speed Automatic Tuning Scheme
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具有高速自动调谐方案的 1 GHz 等纹波低通滤波器
DOI：
10.1109/tvlsi.2009.2034527
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发表时间：
2011
影响因子：
2.8
通讯作者：
C. Hung
中科院分区：
文献类型：
--
作者：
Tien;C. Hung
本文提出了一种带自动调谐电路的连续时间四阶等波纹线性相位Gm-C滤波器。实现了一种基于逆变器结构的高速OTA。共模前馈和共模反馈相结合的电路保证了输入输出共模稳定性。通过在输出节点处结合等效负阻电路，可以保持增益性能。通过使用深NWELL技术，可以通过调节体电压来实现跨导调谐。改进的自动调谐电路放宽了对调谐块的速度要求。通过使用运算放大器作为自动调谐方案的构建模块，滤波器-3 dB截止频率为1 GHz，群延迟小于4%的变化，直到1.5 fc频率。在-4dbm双音信号情况下，在滤波器截止频率处获得了-43dB的IM3。该芯片采用0.18 μ mCMOS工艺实现，在1.5V电源电压下，芯片面积为1mm2，功耗为175mW。
A continuous-time fourth-order equiripple linear phase Gm-C filter with an automatic tuning circuit is presented. A high speed OTA based on the inverter structure is realized. The combined common-mode feedforward and common-mode feedback circuit ensures the input and output common-mode stability. The gain performance could be maintained by combining an equivalent negative resistor circuit at the output nodes. Transconductance tuning can be achieved by adjusting the bulk voltage by using the deep-NWELL technology. The modified automatic tuning circuit relaxes the speed requirement of the tuning blocks. Through the use of the operational transconductance amplifier as a building block with the automatic tuning scheme, the filter - 3 dB cutoff frequency is 1 GHz with the group delay less than 4% variation up to 1.5 fc frequency. The - 43 dB of IM3 at filter cutoff frequency is obtained with -4 dbm two-tone signals. Implemented in 0.18-μ m CMOS process, the chip occupies 1 mm2 and consumes 175 mW at a 1.5-V supply voltage.