Universal Filter Based on Compact CMOS Structure of VDDDA

Abstract

This paper proposes the simulated and experimental results of a universal filter using the voltage differencing differential difference amplifier (VDDDA). Unlike the previous complementary metal oxide semiconductor (CMOS) structures of VDDDA that is present in the literature, the present one is compact and simple, owing to the employment of the multiple-input metal oxide semiconductor (MOS) transistor technique. The presented filter employs two VDDDAs, one resistor and two grounded capacitors, and it offers low-pass: LP, band-pass: BP, band-reject: BR, high-pass: HP and all-pass: AP responses with a unity passband voltage gain. The proposed universal voltage mode filter has high input impedances and low output impedance. The natural frequency and bandwidth are orthogonally controlled by using separated transconductance without affecting the passband voltage gain. For a BP filter, the root mean square (RMS) of the equivalent output noise is 46 µV, and the third intermodulation distortion (IMD3) is −49.5 dB for an input signal with a peak-to peak of 600 mV, which results in a dynamic range (DR) of 73.2 dB. The filter was designed and simulated in the Cadence environment using a 0.18-µm CMOS process from Taiwan semiconductor manufacturing company (TSMC). In addition, the experimental results were obtained by using the available commercial components LM13700 and AD830. The simulation results are in agreement with the experimental one that confirmed the advantages of the filter.

Electronically and Orthogonally Tunable SITO Voltage-Mode Multifunction Biquad Filter Using LT1228s

“…The simulation results in Figs. [6][7][8][9][10][11] indicate that the proposed filter operates well as expected. The operational frequency is around 10 MHz.…”

“…The biquad filters in [7], [9], [11], [13], [15]- [17] are multiple input multiple output, and the filters in [8], [10], [14], [18] are multiple input single output configuration. The biquad multifunction filters in [8]- [10] are constructed from the different commercially available ICs. The filters in [15], [16] consist of five LT1228s.…”

“…In [10], [14], [18], these filters employ the floating capacitor, while the proposed filter uses grounded capacitors which ensure the compensation of the parasitic effects in ABB. The filters in [7], [8], [10], [14], [18] cannot simultaneously provide several filter responses. Although the proposed filter provides only LP, HP, and BP responses, but it is sufficient to be applied in some applications, such as the three-way crossover network.…”

“…The biquad multifunction filters utilizing LT1228 as an active element were proposed in [12], [13], [15], [16]. The ABB employed [8]- [10] is constructed from the different commercially available ICs. Some filters proposed in [10], [14], [18] don't use the grounded capacitors.…”

“…As a result, it requires the buffer to connect the other circuits. Both ω 0 and Q of the proposed filters in [7], [9], [11], [14], [18] cannot be offered electronic controllability, while the circuits proposed in [8], [10], [12], [14], [17], [18] cannot be independently tuned.…”