High Speed Transconductance-C-Opamp Integrator Using Current-Feedback Amplifier

Takahide SATO  Shigetaka TAKAGI  Nobuo FUJII 

Publication
IEICE TRANSACTIONS on Electronics  Vol.E88-C  No.6  pp.1166-1171
Publication Date: 2005/06/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Analog Circuit and Device Technologies)
Category: Building Block
Keyword: 
transconductance-C-opamp integrator,  analog continuous filter,  current-feedback amplifier, 

Full Text: PDF(279.3KB)

Summary: 
A high-speed transconductance-C-opamp integrator using a current-feedback amplifier is proposed. The integrator has good frequency response compared with a conventional transconductance-C-opamp integrator using a voltage-feedback amplifier. The current-feedback amplifier shifts the second pole of the proposed integrator to the upper frequency. The frequency is proportional to the current gain of the current-feedback amplifier. The proposed integrator can eliminate effects of the parasitics at the output node of the transconductance since the voltage at the node is fixed. One of the circuit examples of the proposed integrator is shown. Its validity is confirmed through HSPICE simulations. The proposed integrator works as predicted up to 260 MHz.