A 3rd-order current-mode filter in 0.12 μm CMOS

Abstract. For software radio applications in system-on-chips, a 3rd-order current-mode Butterworth filter in 120 nm CMOS is realized. This filter is used for reconstruction purposes between a current-steering DAC and a current-mode mixer. Power can be reduced by using a current-mode architecture. The cut-off frequency of this filter is switchable between 1 MHz and 4 MHz, the current consumption is 4.5 mA at V_DD=1.5 V, the inband noise density is 100 pA/√Hz and it has a dynamic range up to 65 dB.