Title :
A BiCMOS analog front-end circuit for an FDM-based ADSL system
Author :
Langford, D. Scott ; Tesch, Bruce J. ; Williams, Brian E. ; Nelson, G. Rodney, Jr.
Author_Institution :
Innovative Design Solutions, Melbourne, FL, USA
fDate :
9/1/1998 12:00:00 AM
Abstract :
This BiCMOS analog front-end (AFE) integrated circuit contains the analog transmit function and a low-noise receiver for FDM-based ADSL systems. The IC includes a current steered 14-bit 5-Msps D/A converter, laser trimmed third-order reconstruction and anti-alias filters, a programmable attenuator with 200-ohm output drive capability, 60-dB of RX programmable gain, and a serial interface. Trimmable thin-film resistors allow ±4% filter cutoff frequency and absolute gain accuracy. The multitone power ratio performance of the part is approximately 65 dB with a spurious free dynamic range >70 dBc. The CMRR of the RX channel is >90 dB@1.1 MHz. PSRR for transmit and receive are greater than 60 dB. The isolation features of the 1.2-μm BiCMOS technology allow transmit and receive to operate in full-duplex mode with greater than 80 dB of cross-talk isolation. The chip size is 25.8 mm2 which includes bond pads and electrostatic discharge protection devices
Keywords :
BiCMOS analogue integrated circuits; frequency division multiplexing; subscriber loops; 1.1 MHz; 1.2 micron; ADSL system; BiCMOS analog front-end integrated circuit; CMRR; D/A converter; FDM; PSRR; analog transmit function; anti-alias filter; bond pad; crosstalk isolation; dynamic range; electrostatic discharge protection device; full-duplex mode; laser trimmed reconstruction filter; low-noise receiver; multitone power ratio; programmable attenuator; serial interface; thin film resistor; Analog integrated circuits; Attenuators; BiCMOS integrated circuits; Cutoff frequency; Dynamic range; Filters; Isolation technology; Laser beam cutting; Resistors; Transistors;
Journal_Title :
Solid-State Circuits, IEEE Journal of
