A 7.2 GHz Bipolar Operational Transconductance Amplifier for Fully Integrated OTA-C Filters

1994 ◽  
pp. 67-77
Author(s):  
M. Atarodi ◽  
J. Choma
2017 ◽  
Vol 15 ◽  
pp. 149-155 ◽  
Author(s):  
Jochen Briem ◽  
Marco Mader ◽  
Daniel Reiter ◽  
Raul Amirpour ◽  
Markus Grözing ◽  
...  

Abstract. This paper presents an electrical, fully integrated, high quality (Q) factor GmC bandpass filter (BPF) stage for a wireless 27 MHz direct conversion receiver for a bendable sensor system-in-foil (Briem et al., 2016). The core of the BPF with a Q factor of more than 200 is an operational transconductance amplifier (OTA) with a high linearity at an input range of up to 300 mVpp, diff. The OTA's signal-to-noise-and-distortion-ratio (SNDR) of more than 80 dB in the mentioned range is achieved by stabilizing its transconductance Gm with a respective feedback loop and a source degeneration resistors RDG. The filter stage can be tuned and is tolerant to global and local process variations due to offset and common-mode feedback (CMFB) control circuits. The results are determined by periodic steady state (PSS) simulations at more than 200 global and local process variation parameter and temperature points and corner simulations. It is expected, that the parasitic elements of the layout have no significant influence on the filter behaviour. The current consumption of the whole filter stage is less than 600 µA.


2021 ◽  
Vol 16 (2) ◽  
pp. 1-11
Author(s):  
Rafael Sanchotene Silva ◽  
Luís Henrique Rodovalho ◽  
Jefferson Luiz Brum Marques ◽  
Cesar Ramos Rodrigues

This paper presents a novel differential pA/V Operational Transconductance Amplifier (OTA) topology. The circuit is suitable for the implementation of fully integrated operational transconductance amplifier-capacitance (OTA-C) filters with small feature size capacitors, suited for electrophysiological signal acquisition and conditioning. Unlike typical OTA-Cs, the proposed topology consists of transconductance reduction technique based on unbalanced output branches thatallow current subtraction thus enabling transconductances in the order of pA/V. The technique is demonstrated through the design of a 59pA/V transconductor, which is very suited for designing long-time-constant filters. This OTA-C achieved a worst-case 0.35% THD with just 61.7nW average power consumption, which allows its applicability to biomedical implants. Simulations were carried out with STMicroelectronics 0.13µm HCMOS9 node using Cadence’s IC design tools. Weemployed the OTA in a design of a fourth-order bandpass filter with a narrow bandwidth of 12.5–21.8Hz. Similar results to the ideal transfer function, turn the proposed OTA ideal for biosensing-based applications.


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