AFE1224

Burr-Brown's Analog Front End minimizes the size and cost of a single pair High bit rate Digital Subscriber Line (HDSL) system by providing all of the active analog circuitry needed to connect an HDSL digital signal processor to an external compromise hybrid and an HDSL line transformer. The transmit and receive filter responses automatically change with clock frequency, allowing the AFE1224 to operate over a wide range of data rates. The power dissipation of the device can be reduced under digital control for operation at lower speeds. The AFE1224 will operate at bit rates from 64kbps to 2.320Mbps.

Functionally, this unit consists of a transmit and a receive section. The transmit section generates analog signals from 2-bit digital symbol data and filters the analog signals to create 2B1Q symbols. The on-board differential line driver provides a 13.5dBm signal to the telephone line. The receive section filters and digitizes the symbol data received on the telephone line. The AFE1224 operates on a single 5V supply. The digital circuitry in the unit can be connected to a supply from 3.3V to 5V. The chip uses only 355mW for full-speed operation. It is housed in a 28-lead SSOP package.