Luciano Tomasini

100-V high-performance amplifiers in BCD technology for SLIC applications

The circuits described in this paper are a line driver and a sensing amplifier. They are part of a Subscriber Line Interface Circuit (SLIC) fabricated in BCD technology that operates up to 100 V. The driver requires about 500 ¿A of quiescent current, can sink and source up to 100 mA, and remains stable for all possible line lengths. The sensing amplifier senses the line current to synthesize both the ac and DC line termination. It achieves a 2 mV offset and a gain-bandwidth product of 2.5 MHz. The adopted mixed technology allows the realization of a compact single chip SLIC.

Analog front end of an ECBM transceiver for ISDN

The analog front end of an echo cancellation burst mode (ECBM) transceiver operating from a single 5-V supply is described. The chip performs pulse shaping and line driving in the transmit section and hybrid function, equalization, A/D and D/A conversion, automatic gain control, threshold detection for a phase-locked loop (PLL), and wake-up in the receive section. The partitioning between analog and digital functions is explained. The analog portion of the chip is described for both the receive and transmit portions, and design considerations for the various building blocks are outlined. The chip contains 45 amplifiers of seven different types and three different types of comparators and dissipates about 160 mW in the normal operation mode and 5 mW in the power-down mode. The die area is 50000 mil/sup 2/ in a 2- mu m, double-poly, single-metal CMOS technology. >

A BiCMOS speech circuit with only two external components

This paper reports on a telephone chip that performs all the basic functions of a speech circuit using only two external components. Precision filtering using Switched Capacitor (SC) techniques is used to implement on-chip impedance termination, hybrid with sidetone cancellation and DC characteristics starting from a single 1% external resistor. Better than 30 dB matching is achieved without any external trimming. The TX linearity is better than 50 dB up to 4.4 Vpp on the line. The chip has an active area of approximately 4,000 mils2 and draws 1.5 mA from the supply.

A BiCMOS Speech Circuit with only Two External Components

This paper reports on a telephone chip that performs all the basic functions of a speech circuit using only two external components. Precision filtering using Switched Capacitor (SC) techniques is used to implement on-chip impedance termination, hybrid with sidetone cancellation and DC characteristics starting from a single 1% external resistor. Better than 30 dB matching is achieved without any external trimming. The TX linearity is better than 50 dB up to 4.4 Vpp on the line. The chip has an active area of approximately 4,000 mils2 and draws 1.5 mA from the supply.