Integrated continuous-time filter design - an overview

A Low Power, Fully Differential Bulk Driven OTA in 180 nm CMOS Technology

“…Single ended small signal equivalent circuit of the differential feed-forward OTA is shown in Fig. 6 and the corresponding transfer function can be written as in (2). A bulk driven feed-forward compensated OTA then built using the transconductors.…”

“…However, low output impedance requirement of Opamp makes it power hungry. For this reason, OTAs are widely used in place of Opamps but with some careful design [1], [2]. Various designs of OTA are described in the literature.…”

A systematic approach to circuit design and analysis: classification of two-VCCS circuits

“…This electronic variability allows for on-chip self-correction for spread in IC-processing and temperature variations (e.g., f-tuning in Gm-C filters [37], [38]). Moreover, it enables adaptive signal processing (e.g., AGC [39]).…”

Active N-path Filters: Theory and Design

“…These filters were typically off-chip, bulky and expensive which led to penalties in terms of cost, form factor and less design flexibility. The push towards single-chip solutions led to a tremendous amount of research on the integration of these bandpass filters [9,10,11,12,13,14,15,16]. Analog BPFs have been notoriously difficult to implement on-chip.…”

“…The success of commercial wireless communication products is due, in part, to the inclusion of highly integrated radio frequency (RF) transceivers which feature low cost, low power consumption, and performance levels that meet demanding system specifications. The architecture of integrated RF transceivers has been largely determined by RF bandpass filter performance and system requirements [9]. Early radio architectures such as super-heterodyne needed several bandpass filters (BPF) in the receiver or transmitter chain to suppress interference and image signals.…”