Balanced Output Transconductor Research Articles

New Four-Quadrant CMOS Current-Mode and Voltage-Mode Multipliers

In this paper, a four-quadrant current-mode multiplier based on a new squarer cell is proposed. The multiplier has a simple core, wide input current range with low power consumption, and it can easily be converted to a voltage-mode by using a balanced output transconductor (BOTA) [1]. The proposed four-quadrant current-mode and voltage-mode multipliers were confirmed by using PSPICE simulation and found to have good linearity with wide input dynamic range. For the proposed current-mode multiplier, the static power consumption is 0.671 mW, the maximum power consumption is 0.72 mW, the input current range is ±60 µA, the bandwidth is 31 MHz, the input referred noise current is 46 pA/√Hz, and the maximum linearity error is 3.9%. For the proposed voltage-mode multiplier, the static power consumption is 1.6 mW, the maximum power consumption is 1.85 mW, the input voltage range is ±1V from ±1.5V supply, the bandwidth is 25.34 MHz, the input referred noise voltage is 0.85 µV/√Hz, and the maximum linearity error is 4.1%.

DIGITALLY CONTROLLED CMOS BALANCED OUTPUT TRANSCONDUCTOR AND APPLICATION TO VARIABLE GAIN AMPLIFIER AND GM-C FILTER ON FIELD PROGRAMMABLE ANALOG ARRAY

A digitally controlled balanced output transconductor (DCBOTA) is proposed and analyzed. The proposed DCBOTA is based on the BOTA given in Ref. 1 and MOS switches. The DCBOTA transconductance is tunable in a range of 2n-1 times using n bits control word. The proposed DCBOTA is simulated using CMOS 0.35 μm technology and the results have shown the feasibility of the proposed DCBOTA. The simulation results show that the DCBOTA has a transconductance tuning range from 20 μA/V to 140 μA/V using 3 bits control word and a 3-dB bandwidth larger than 80 MHz. A general configurable analog block (CAB) based on the proposed DCBOTA, capacitor array and MOS switches, is also presented. A collection of the CABs, fully differential buffers (FDBUFs), and their interconnection to construct a field programmable analog array (FPAA) is introduced. The DCBOTA is also used to realize a wide band digitally controlled variable gain amplifier (DCVGA) and six-order lowpass filter with variable gain and tunable cutoff frequency from 1 MHz to 7 MHz.

A New CMOS Rail-to-Rail Low Distortion Balanced Output Transconductor

This paper presents a new CMOS transconductor providing low distortion for rail-to-rail signals. The circuit is based on using the anti-phase common source topology with the floating current source to extend its linearity range. The difference in the biasing currents of the floating current source is compensated to maintain the two output currents balanced by subtracting it at the output nodes. The proposed transconductor is suitable for applications requiring wide dynamic ranges. Rail-to-rail operation is achieved with THD less than −37 dB. The bandwidth achieved by the transconductor is 67.5 MHz using a supply voltage of ±1.5 V.

A Modified CMOS Balanced Output Transconductor with Extended Linearity

A new CMOS balanced output transconductor is presented. The circuit is based on applying the dynamic biasing technique on the floating current source to extend its linearity range. The difference i...

CMOS balanced output transconductor and applications for analog VLSI

A new CMOS programmable balanced output transconductor (BOTA) is introduced. The BOTA is a useful block for continuous-time analog signal processing. A new CMOS realization based on MOS transistors operating in the saturation region is given. Application of the BOTA in realizing bandpass–lowpass–allpass–notch biquad mixed mode filter using four BOTAs and two grounded capacitors and in realizing current mode MOS-C oscillators using three or four BOTAs and two grounded capacitors are given. PSpice simulation results for the BOTA circuit and for its applications are also included.

A New CMOS Programmable Balanced Output Transconductor and Application to a Mixed Mode Universal Filter Suitable for VLSI

A new CMOS programmable balanced output transconductor (BOTA) is introduced. The BOTA is a useful block for continuous-time analog signal processing. A new CMOS realization based on MOS transistors operating in the saturation region is given. Application of the BOTA in realizing a mixed mode universal filter using six BOTAs and two grounded capacitors is also introduced. The filter’s gain can be adjusted simply by varying the amplitude of a transconductance through its control voltage without affecting \omega_{\rm 0} and Q of the filter. Also, the Q of the filter can be adjusted by a single transconductor independent of \omega_{\rm 0}. PSpice simulation results for the BOTA circuit and for the universal filter are also given.

A CMOS programmable balanced output transconductor for analogue signal processing

A new CMOS programmable balanced output transconductor (BOTA) is introduced. The BOTA is a useful block for continuous-time analogue signal processing. A new CMOS realization of the BOTA is given. The proposed realization is based on the cascaded connection of a new voltage controlled differential transconductor, a voltage controlled MOS grounded resistor and a balanced output transconductor stage. Applications of the BOTA in realizing a floating resistor, a balanced output differential integrator, a continuous-time balanced output bandpass–lowpass filter, a floating inductor and the active realization of the RLC filters using a minimum number of the BOTA are given. PSpice simulation results for the BOTA circuit and for its applications are also given.