A hybrid integrated trunk and subscriber line interface
A two-chip hybrid integrated trunk and subscriber line interface has been fabricated for voice and data applications. This paper will discuss features including a programmable battery feed with lightning protection, battery-reversal signaling, 2-4 wire conversion, loop closure detection and power down capability.
A Versatile Subscriber Line Interface Circuit
This paper will describe a bipolar SLIC LSI for telephone switching. The aluminum master slices accommodate central offices as well as PABXs, ie. constant resistance feed and constant current feed. The SLICs are programmable by the external components to meet any of line impedance requirements.
Ion implanted, compatible, complementary PNP's for high slew rate operational amplifiers
A compatible complementary pnp transistor with usable breakdown voltage has been developed which allows a significant improvement in the slew rate of monolithic integrated circuit amplifiers with low to moderate standby power. Monolithic circuits with high speed npn's and lateral pnp's can be made with high slew rates, but only at the expense of standby power. As this power becomes too large to remove from the chip, the performance is limited. Compatible, complementary pnp's allow the node capacitances to be charged with high currents with low standby power, thus allowing a significant increase in circuit performance. The triple diffused vertical pnp's reported earlier are not acceptable in amplifiers because of the low collector-emitter breakdown of approximately 7.5 volts. A similar acceptable two epi process has been reported using diffusion, however, the process described herein provides much tighter control on device parameters.