AFE1115

® AFE 111 5 ® AFE1115 HDSL/MDSL ANALOG FRONT END WITH VCXO FEATURES q COMPLETE HDSL ANALOG INTERFACE q E1, T1 AND MDSL OPERATION q VCXO AND VCXO CONTROL CIRCUITRY q +5V ONLY (5V or 3.3V Digital) q SCALEABLE DATA RATE q 300mW POWER DISSIPATION q 56-PIN SSOP DESCRIPTION Burr-Brown’s Analog Front End greatly reduces the size and cost of an HDSL (High bit rate Digital Subscriber Line) system by providing all of the active analog circuitry needed to connect an HDSL digital signal processor to an external compromise hybrid and a HDSL line transformer. The transmit and receive filter responses automatically change with clock frequency—allowing the AFE1115 to operate over a range of data rates from 196kbps to 1.168Mbps. Functionally, this unit consists of a transmit and a receive section with a VCXO (Voltage Controlled vcDATA vcSCLK vcLE VCXO DAC Oscillator Crystal Oscillator) control DAC and VCXO circuitry. The transmit section generates, filters, and buffers outgoing 2B1Q data. The receive section filters and digitizes the symbol data received on the telephone line. Data to the VCXO and symbol data are sent to the AFE1115 via two serial interfaces; the receive data is available as a 14-bit parallel word. This IC operates on a single 5V supply. The digital circuitry in the unit can be connected to a supply from 3.3V to 5V. It is housed in a small 56-pin SSOP package. vcDAC VCXO Output VCXO Input VCXO Output Clock Pulse Former Filter Output Buffer txLINE+ txLINE– PLLOUT ...