A 0.18μm CMOS 300MHz Current-Mode LF Seventh-order Linear Phase Filter for Hard Disk Read Channels
A 300MHz CMOS seventh-order linear phase gm-C filter based on a current-mode multiple loop feedback (MLF) leap-frog (LF) structure is realized. The filter is implemented using a fully-differential linear operational transconductance amplifier (OTA) based on a source degeneration topology. PSpice simulations using a standard TSMC 0.18μm CMOS process with 2.5V power supply have shown that the cut-off frequency of the filter can be tuned from 260MHz to 320MHz and dynamic range is about 66dB. Group delay ripple is approximately 4.5% over the whole tuning range and maximum power consumption is 210mW.