GENERAL DESCRIPTION

The STLC1511 G.lite Analog Front End (AFE) chip implements the analog transceiver functions required in both a central office modem and a customer premise modem. It connects the digital modem chip with the loop driver and hybrid balance circuits. The STLC1511 has been designed with excellent dynamic range in order to greatly reduce the external filtering requirements at the front end. The AFE chip and its companion digital chip along with a loop driver, implement the complete G.992.2 DMT modem solution. The STLC1511 transmit path consists of a 14-bit Nyquist rate D/A converter, followed by a programmable gain amplifier (TxPGA). The transmit gain is programmable from 0 to -32dB in 2dB steps.

■ Wide transmit (~80dB) and receive (~69dB) dynamic range to limit the external filtering requirements for extended loop reach operation

■ Programmable tx gain: 0 ÷ -32dB in 2dB steps

■ 14-bit D/A converter in transmit path

■ Programmable rx gain: 0 ÷40dB in 0.5dB steps

■ 12-bit A/D converter in receive path

■ Integrated phase-locked loop with an externall LC or crystal oscillator

■ Low power: 300mW @ 5.0V

■ 64-pin TQFP package