Gea-ok Cho

RF AMP IC for Optical Disc Player

This paper describes RF amp integrated circuit for the read channel of optical disc players that include CD and DVD demanding the equalizer and the decision block. A RF equalizer is composed of boosting filter to slim the data pulse and 9th order Bessel filter to attenuate high frequency noise. Boosting filter emphasize 6dB at 6MHz and maintains the linear phase within 1% by pole zero cancellation method. An important advantage is tuneability of the boosting and frequency characteristics by controlling the transconductance, therefore, it is enough to cover the tolerance of fabrication. The high frequency noise due to equalization is attenuated by 9th order Bessel filter which has the slope of over -42dB/oct. Measured jitter keeps within 4.5n. The decision block includes one bit analog to digital converter and the low pass filters to detect asymmetry and asymmetric amp. As the analog and the digital signals are mixed on a chip, the main ground and the NMOS bulk ground, DGND and AGND respectively, are separated. Also, it is laid out very carefully to minimize the digital noise in analog block Implemented in a 0.8um CMOS n-well technology, the RF equalizer and the decision block chip occupy 3000um × 1000um. Power consumption from asingle 5V is around 300mW.