This is the peer-reviewed version of the following article: Masood-ul Hasan, Yanqing Zhu, and Yichuang Sun, ???Design for testability of high-order OTA-C filters???, International Journal of Circuit Theory and Applications, Vol. 44 (10): 1859-1873, October 2016, which has been published in final form at doi: 10.1002/cta.2200. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Copyright ?? 2016 John Wiley & Sons, Ltd.A study of oscillation-based test for high-order Operational Transconductance Amplifier-C (OTA-C) filters is presented. The method is based on partition of a high-order filter into second-order filter functions. The opening Q-loop and adding positive feedback techniques are developed to convert the second-order filter section into a quadrature oscillator. These techniques are based on an open-loop configuration and an additional positive feedback configuration. Implementation of the two testability design methods for nth-order cascade, IFLF and leapfrog (LF) filters is presented, and the area overhead of the modified circuits is also discussed. The performances of the presented techniques are investigated. Fourth-order cascade, inverse follow-the-leader feedback (IFLF) and LF OTA-C filters were designed and simulated for analysis of fault coverage using the adding positive feedback method based on an analogue multiplexer. Simulation results show that the oscillation-based test method using positive feedback provides high fault coverage of around 97%, 96% and 95% for the cascade, IFLF and LF OTA-C filters, respectively. Copyright ???? 2016 John Wiley & Sons, Ltd

Abstract-A fully-differential seventh-order 0.05° equiripple linear phase low-pass filter based on multiple loop feedback (MLF) leapfrog (LF) topology is presented for read/write channels. The filter is designed and simulated with the proposed fully balanced, highly linear operational transconductance amplifier (OTA). This OTA contains two complementary differential cross-coupled input pairs and a pair of regulated cascode output in order to achieve both lowdistortion and wide dynamic rang in high-frequency operation. Simulations in 0.25µm CMOS show that the cutoff frequency of the low pass filter without and with gain boost ranges from 50 to 150MHz and 65 to 250MHz respectively, dynamic-range is over 65dB and total harmonic distortion is less than 40dB. The group delay ripple is less than 5% for frequencies up to 1.5 times of the cutoff frequency, and for a 2-volt power supply, the maximum power consumption is 216mW.

Original article is available at : http://www.springerlink.com/ Copyright Springer [Full text of this article is not available in the UHRA]Design and performance comparison of high-order operational transconductance amplifier and capacitor (OTA-C) filters using leapfrog (LF) and inverse-follow-the-leader-feedback (IFLF) structures are investigated. The filters are designed for a 125 MHz seventh-order equiripple group delay lowpass characteristic with and without gain boost and simulated in 0.25 ??m 2-V CMOS. A fully differential highly linear OTA with cross-coupled input pairs and regulated cascode output is used for the simulation. Simulated results show that while the IFLF OTA-C filter can achieve a higher gain boost, the LF OTA-C filter has better other performances

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