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

Wai, May Phu Pwint; Suwanjan, Peerawut; Jaikla, Winai; Chaichana, Amornchai

doi:10.5755/j02.eie.28949

Cited by 3 publications

(25 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to its wide transconductance amplifier, high voltage-gain, large signal bandwidth, wide supply voltage, high accuracy, and high drive capability, the commercially available LT1228 IC is an interesting electronically tunable active component suitable for many circuit designs. As a result, many active VM second-order filters, oscillators, inductance simulators, and wave generators based on the attractive commercial LT1228 ICs were proposed in the literature [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. The LT1228 implements gain-controlled through a transconductance g m at the front end and a CFA at the back end, and combines these two amplifiers into an 8-pin package [ 49 ].…”

Section: Introductionmentioning

confidence: 99%

“…According to [ 32 ], two interesting independent amplitude VM BPFs are proposed, but both the HPF and LPF cannot be simultaneously obtained in each circuit configuration. The high-fidelity three-way speaker system uses one HPF, one BPF, and one LPF to connect the tweeter, midrange, and woofer, so the HPF, BPF, and LPF structures must be simultaneously implemented in the circuit design [ 31 , 33 ]. An interesting LT1228-based electronically tunable VM second-order multifunction filter is presented in [ 33 ], which simultaneously implements HPF, BPF, and LPF transfer functions from the same circuit configuration.…”

Section: Introductionmentioning

confidence: 99%

“…The high-fidelity three-way speaker system uses one HPF, one BPF, and one LPF to connect the tweeter, midrange, and woofer, so the HPF, BPF, and LPF structures must be simultaneously implemented in the circuit design [ 31 , 33 ]. An interesting LT1228-based electronically tunable VM second-order multifunction filter is presented in [ 33 ], which simultaneously implements HPF, BPF, and LPF transfer functions from the same circuit configuration. According to [ 33 ], the circuit has the following features: (i) The filter can simultaneously generate VM second-order HPF, BPF, and LPF transfer functions, and is suitable for three-way crossover networks.…”

Section: Introductionmentioning

confidence: 99%

“…An interesting LT1228-based electronically tunable VM second-order multifunction filter is presented in [ 33 ], which simultaneously implements HPF, BPF, and LPF transfer functions from the same circuit configuration. According to [ 33 ], the circuit has the following features: (i) The filter can simultaneously generate VM second-order HPF, BPF, and LPF transfer functions, and is suitable for three-way crossover networks. (ii) The parameters of the filter, ω o and Q, permit for electronic and orthogonal controllability.…”

Section: Introductionmentioning

confidence: 99%

“…In this paper, two new synthesis methods for VM LT1228-based second-order multifunction filters based on non-inverting/inverting HPF transfer functions are designed and developed. Each of the two proposed designed and synthesized VM second-order multifunction filters uses three commercial LT1228s, five resistors, and two grounded capacitors, which is one more resistor than the filter topology implemented in [ 33 ], to achieve two independent gain-controlled filter responses. Both the designed and the synthesized VM second-order multifunction filters have the following advantages.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Synthesis of High-Input Impedance Electronically Tunable Voltage-Mode Second-Order Low-Pass, Band-Pass, and High-Pass Filters Based on LT1228 Integrated Circuits

Chen¹,

Chen²,

Chang³

2022

Sensors

View full text Add to dashboard Cite

This paper introduces two new high-input impedance electronically tunable voltage-mode (VM) multifunction second-order architectures with band-pass (BP), low-pass (LP), and high-pass (HP) filters. Both proposed architectures have one input and five outputs, implemented employing three commercial LT1228 integrated circuits (ICs), two grounded capacitors, and five resistors. Both proposed architectures also feature one high-impedance input port and three low-impedance output ports for easy connection to other VM configurations without the need for VM buffers. The two proposed VM LT1228-based second-order multifunction filters simultaneously provide BP, LP, and HP filter transfer functions at Vo1, Vo2, and Vo3 output terminals. The pole angular frequencies and the quality factors of the two proposed VM LT1228-based second-order multifunction filters can be electronically and orthogonally adjusted by the bias currents from their corresponding commercial LT1228 ICs, and can be independently adjusted in special cases. In addition, both proposed VM LT1228-based second-order multifunction filters have two independent gain-controlled BP and LP filter transfer functions at Vo4 and Vo5 output terminals, respectively. Based on the three commercial LT1228 ICs and several passive components, simulations and experimental measurements are provided to verify the theoretical predictions and demonstrate the performance of the two proposed high-input impedance electronically tunable VM LT1228-based second-order multifunction filters. The measured input 1-dB power gain compression point (P1dB), third-order IMD (IMD3), third-order intercept (TOI) point, and spurious-free dynamic range (SFDR) of the first proposed filter were −7.1 dBm, −48.84 dBc, 4.133 dBm, and 45.02 dBc, respectively. The measured input P1dB, IMD3, TOI, and SFDR of the second proposed filter were −7 dBm, −49.65 dBc, 4.316 dBm, and 45.88 dBc, respectively. Both proposed filters use a topology synthesis method based on the VM second-order non-inverting/inverting HP filter transfer functions to generate the BP, LP and HP filter transfer functions simultaneously, making them suitable for applications in three-way crossover networks.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Synthesis of High-Input Impedance Electronically Tunable Voltage-Mode Second-Order Low-Pass, Band-Pass, and High-Pass Filters Based on LT1228 Integrated Circuits

Chen¹,

Chen²,

Chang³

2022

Sensors

View full text Add to dashboard Cite

show abstract

Two New and Improved Electronically Adjustable Voltage-Mode Multifunction Biquadratic Filters With Independent Control of Band-Pass, High-Pass, and Low-Pass/Regular Notch Filter Gains

et al. 2023

View full text Add to dashboard Cite

In this study, two new and improved electronically adjustable voltage-mode (VM) biquadratic filters using three off-the-shelf LT1228 integrated circuits (ICs), two grounded capacitors (GCs), and six resistors are proposed for independent control of the band-pass (BP), high-pass (HP), and low-pass/regular notch (LPN/RN) filter gains. Each proposed electronically adjustable VM multifunction biquadratic filter has one input and six output voltages, enabling simultaneous realization of one low-pass (LP), two BP, two HP, and one LPN/RN filtering responses from the same configuration. Each filter parameter, namely the pole angular frequency (ω o ) and quality factor (Q), can be electronically controlled and orthogonally adjusted by the corresponding LT1228 bias current I B . In special cases, the parameters of ω o and Q can be electronically controlled and independently adjusted. Each electronically adjustable VM multifunction biquadratic filter has one high input impedance and three low output impedances for independent control of BP, HP, and LPN/RN filter gains. Due to its one high input impedance and three low output impedances, each proposed filter is suitable for cascaded VM circuits without external voltage buffers. Pspice simulations are used to verify the theoretical structure analysis of each proposed LT1228-based electronically adjustable VM multifunction biquadratic filter. Furthermore, experimental tests are performed using three off-theshelf LT1228 ICs, and several passive components to verify and evaluate the performance of each proposed LT1228-based biquadratic filter.INDEX TERMS LT1228, analog circuit design, integrated circuits, voltage-mode, filters.

show abstract

Design and Verification of a New Universal Active Filter Based on the Current Feedback Operational Amplifier and Commercial AD844 Integrated Circuit

Chen,

Wey,

Chen

et al. 2023

Sensors

View full text Add to dashboard Cite

This paper presents a triple-input and four-output type voltage-mode universal active filter based on three current-feedback operational amplifiers (CFOAs). The filter employs three CFOAs, two grounded capacitors, and six resistors. The filter structure has three high-input and three low-output impedances that simultaneously provide band-reject, high-pass, low-pass, and band-pass filtering functions with single-input and four-output type and also implements an all-pass filtering function by connecting three input signals to one input without the use of voltage inverters or switches. The same circuit configuration enables two unique filtering functions: low-pass notch and high-pass notch. Three CFOAs with three high-input and low-output impedance terminals enable cascading without voltage buffers. The circuit is implemented using three commercial off-the-shelf AD844 integrated circuits, two grounded capacitors, and six resistors and further implemented as a CFOA-based chip using three CFOAs, two grounded capacitors, and six resistors. The CFOA-based chip has lower power consumption and higher integration than the AD844-based filter. The circuit was simulated using OrCAD PSpice to verify the AD844-based filter and Synopsys HSpice for post-layout simulation of the CFOA-based chip. The theoretical analysis is validated and confirmed by measurements on an AD844-based filter and a CFOA-based chip.

show abstract

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

Cited by 3 publications

References 14 publications

Synthesis of High-Input Impedance Electronically Tunable Voltage-Mode Second-Order Low-Pass, Band-Pass, and High-Pass Filters Based on LT1228 Integrated Circuits

Synthesis of High-Input Impedance Electronically Tunable Voltage-Mode Second-Order Low-Pass, Band-Pass, and High-Pass Filters Based on LT1228 Integrated Circuits

Two New and Improved Electronically Adjustable Voltage-Mode Multifunction Biquadratic Filters With Independent Control of Band-Pass, High-Pass, and Low-Pass/Regular Notch Filter Gains

Design and Verification of a New Universal Active Filter Based on the Current Feedback Operational Amplifier and Commercial AD844 Integrated Circuit

Contact Info

Product

Resources

About