Design of Current-Mode Square-Root Domain Band-Pass Filter with Reduced Voltage

Abstract

A design technique for current-mode square-root domain band-pass filter fabricated in a 0.25 µm CMOS process is presented. The basic building block consists of current-mode current mirrors, square-root circuits and capacitors, and in which the overall supply voltage is reduced by adopting low-voltage level-shift current mirror. Both of the simulation and measured results, which are in good agreement, indicate that the prototype of the bandpass provides tunable center frequency of 4-10 MHz with bias-current-tunable, −26.7 dB total harmonic distortion (THD), and approximately 1.598 mW power dissipation with a 1.5 V supply voltage. Advantages of the proposed filter include high frequency operation, tuneability, low supply voltage operation, low power consumption, and low third order intermodulation distortion.

Square-Root-Domain Second-Order Trans-Admittance Type Universal Filter Design

“…It should be noted that 0 can electronically be tuned by changing 0 as shown in Eq. ( 8) [11], [17], [22].…”

“…A number of SRD circuits such as first-order filters [13]- [15], second-order voltage-mode (VM) [16], [17] and current-mode (CM) filters [11], [15], [18], [19] and trans-admittance circuits [12], [13], [20] were presented by the authors in the literature. Also, there are some papers in the literature about the squareroot and the squarer/divider structures that were used to obtain trans-admittance type filter circuits [10], [18], [21].…”

1.5 V square‐root domain universal biquad filters

“…A number of second‐order SRD filters have been already proposed in the literature . All of them are multifunction filters in the sense that they are not able to simultaneously realize all the aforementioned filter functions.…”