Active Circulator Circuits Using Oa, Ccii, Cfoa and DVCC

Abstract

A review of the two types of circulators using Operational Amplifiers (OA) with detailed comparison is given. Novel active circulator circuits using Current Conveyors (CCII) and Current Feedback Operational Amplifiers (CFOA) and Differential Voltage Current Conveyor (DVCC) are introduced. The proposed CCII circulator circuit uses six CCIIs and three floating resistors. Two different circulator types using the CFOA are given. A circulator circuit which uses three DVCCs and has the advantage of using three grounded resistors is also introduced.Spice simulation results using 0.5 µm CMOS transistors are included to support the theoretical analysis and demonstrate comparisons among the different types of circulators.

Dual-Mode Controlled Pulse Width Monostable Multivibrator Using DVCCs

“…The voltage-tuned parameter V TU was then be determined using (10). Regarding the RCM operation, the value of R 3 was calculated after the values of R 1 =R 2 and capacitor C were substituted into (13). Regarding the experimental tests, a prototype circuit (Fig.…”

“…Regarding the RCM operation, R 3 ¼ 12:5 k ) R x ¼ 50 was calculated after substituting R 1 ¼ 8:7 k, R 2 ¼ 43 k and C ¼ 100 nF into (13). Figure 5 shows the experimental results for the design example with the pulse width T VCM ¼ T RCM ¼ 1 ms for both operating modes.…”

“…Equation (9) indicates the expression of V TL when I X2 is set equal to I Z2 . The pulse width T RCM of the RCM can be obtained based on (9) and (12), and is presented in (13) …”

“…Equations (10) and (13) indicate that the pulse width of the proposed circuit can be tuned by adjusting the voltage-tuned parameter V TU and resistor R 3 , enabling a dual-mode controlled pulse width design to be achieved. Compared with previous DVCC-based topologies, 20 the proposed circuit o®ers a more versatile scheme to ful¯l the electronic and non-electronic tuning manners for the output pulse within a single con¯guration.…”