Fully digitally programmable voltage mode universal filter

Fully Digitally Programmable Generalized Mixed Mode Universal Filter Configuration

“…Comparison in Table 3 shows that the CM general biquadratic UFs of [18,22] which in limited sense may be considered as analog counterpart of the proposed Generalized DPUF, not only use quite large number of active and/or passive components but also lack number of features. Another application [27], realizing VM DPUF, uses six programmable blocks as used in Generalized DPUF, but it provides programmability of filter parameters only, not the reconfigurability. This feature (reconfigurability) is unique to the Generalized DPUF and is not available in any CC-based reported DPUFs.…”

“…Only the feature in which the proposed configuration lacks is unavailability of inverted response as provided by [1], but this can be easily achieved by taking the output from opposite Z-port. VM DPUF of [27] uses six active elements and provides almost similar features of First Derived configuration. However, it is not reconfigurable and also it uses quite large number of floating elements.…”

Electronically Tunable Current-mode Multifunction Filter Using Current-controlled Current Follower Transconductance Amplifier

“…Current-mode (CM) signal processing circuits received considerable attention because this technique offers several advantages compared to voltage-mode (VM) signal processing circuits, such as greater signal bandwidth, wider dynamic range and especially simpler circuitry [27], [28]. Considering the universal filters in , the circuits in [3][4][5][6][7][8][9][10][11][12] are VM filters while the circuits in [13][14][15][16][17][18][19][20][21][22][23][24][25][26] are CM filters. This paper is focused on the CM filters which are supposed to use only a single active device and grounded capacitors.…”

Reconfigurable Mixed Mode Universal Filter

“…Current feedback amplifier (CFA) plays significant role in area of signal processing/generation because of its higher speed, higher slew rate, simpler circuit realization, and most importantly the independence of gain and bandwidth [1][2][3]. Introduction of digital control/programming in CFA has further boosted its functional flexibilities and versatility [1]. Programmable characteristic of analog block is essential for controlling the undesired parameter variation caused by temperature and process.…”

“…The proposed UF can be reconfigured digitally to realize all the standard second order filter functions, namely, lowpass (LP), highpass (HP), bandpass (BP), band reject (BR), and allpass (AP) at single output port. The proposed DPUF configuration is (1) fully programmable as all the coefficients of its transfer function are independently controlled, which makes its parameters, namely, pole frequency ( 0 ), quality factor ( ), and gain ( ) independently programmable (2) fully cascadable by virtue appropriate (low/high for voltage/current) input and (low for voltage) output port impedances (3) less sensitive to nonidealities and parasitic effects. Use of only two grounded capacitor makes the proposed UF suitable from integration [12].…”