Title :
A CMOS ADSL codec for central office applications
Author :
Siniscalchi, Patrick P. ; Pitz, Jeanne K. ; Hester, Richard K. ; DeSoto, Stewart M. ; Wang, Minsheng ; Sridharan, Sucheendran ; Halbach, Robert L. ; Richardson, Donald ; Bright, William ; Sarraj, Maher M. ; Hellums, James R. ; Betty, Christopher L. ; West
Author_Institution :
Texas Instrum. Inc., Dallas, TX, USA
fDate :
3/1/2001 12:00:00 AM
Abstract :
A CMOS central office codec that supports Full Rate and G.Lite asymmetric digital subscriber line (ADSL) transmission is described. The transmit channel consists of application-dependent digital filters, a 14-bit, 8.832-MSample/s current steering DAC, a 1.104-MHz analog filter, and a programmable attenuator. Due to extensive on-chip digital signal processing, the codec complies with the ADSL transmit power spectral density standards without external filtering. The receive channel contains -17.5 to 33.5 dB of programmable gain staggered strategically across three stages, a 138-kHz analog low-pass filter, a 14-bit, 2.208-MSample/s pipeline ADC, and a digital 138-kHz low-pass filter. The receive channel has a wide input range that can accommodate large line voltages present at the line hybrid circuit. The IC occupies 55.2 mm2 and dissipates 450 mW from a 3.3-V supply
Keywords :
CMOS integrated circuits; codecs; digital subscriber lines; low-power electronics; -17.5 to 33.5 dB; 1.104 MHz; 138 kHz; 14 bit; 3.3 V; 450 mW; CMOS ASDL codec; Full Rate transmission; G.Lite transmission; analog filter; analog low-pass filter; asymmetric digital subscriber line; broadband communication; central office; current steering DAC; digital filter; digital low-pass filter; hybrid circuit; low-voltage IC; on-chip digital signal processing; pipeline ADC; power spectral density; programmable attenuator; programmable gain; receive channel; transmit channel; Attenuators; Central office; Code standards; Codecs; DSL; Digital filters; Digital signal processing; Filtering; Gain; Low pass filters;
Journal_Title :
Solid-State Circuits, IEEE Journal of
