This paper presents a third order continuous time current mode RD modulator for WLAN standard applications. The proposed circuit utilized feedback architecture with scaled and optimized DAC coefficients. At circuit level, we propose a modified cascade current mirror integrator with reduced input impedance which results in more bandwidth and linearity and hence improves the dynamic range. Also, a very fast and precise novel dynamic latch based current comparator is introduced with low power consumption. This ultra fast comparator facilitates increasing the sampling rate toward GHz frequencies. The modulator exhibits dynamic range of more than 60 dB for 20 MHz signal bandwidth and OSR of 10 while consuming only 914 lW from V power supply. The FoM of the modulator is calculated from two different methods, and excellent performance is achieved for proposed modulator. | Design of an ultra low power third order continuous time current mode R modulator for WLAN applications
