In this paper we report a 2.4GHz ultra low power (ULP) CMOS down-converter based on current-reuse bleeding technique with resistive feedback. A new figure of merit maximizing g m f T -to-current ratio has been used to bias the transconductance stage. This single balanced mixer shows a conversion gain of 18.7dB and a noise figure of 11.5dB at 10MHz intermediate frequency (IF). Operating under 0.8V supply, the mixer core consumes 330µW and achieves an IIP3 and ICP1 of -14.9dBm and -21dBm respectively. The LO to IF and LO to RF isolations are 43dB and 28dB respectively.