STLC60134S

STLC60134S is the Analog Front End of the STMicroelectronics Tosca] ADSL chipset and when coupled with TLC60135 (DTM modem) allows to get a T1.413 Issue 2 compliant solution.

The STLC60134S analog front end handles 2 transmission channels on a balanced 2 wire interconnection;a 16 to 640Kbit/s upstream channel and a 1.536 to 8.192Mbit/s downstream channel.

A 256 carrier DMT coding (frequency spacing 4.3125kHz) transforms the downstream channel to a 1MHz bandwidth analog signal (tones 32-255) and the upstream channel (tones 8-31) to a 100kHz bandwidth signal on the line.

This asymmetrical data transmission system uses high resolution, high speed analog to digital and digital to analog conversion and high order analog filtering to reduce the echo and noise in both the ATU-C/ATU-R receivers and transmitters. External low noise driver and input stage used with STLC60134Sguarantee low noise performances.

The STLC60134S chip can be used at ATU-C and ATU-R ends (behaviour set by LTNT pin).The selection consists mainly of a filter interchange between the RX and TX path. The filters (with a programmable cutoff frequency) use automatic Continuous Time Tuning to avoid time varying phase characteristic which can be of dramatic consequencefor DMT modem. It requires few external components, uses a 3.3V supply (a separate 3.0V supply of the digital part is possible)and is packaged in a 64-pin TQFP in order to reduce PCB area.