Browse Prior Art Database

High Speed Sense Amplifier and Dual-Phase Output Circuit

IP.com Disclosure Number: IPCOM000047857D
Original Publication Date: 1983-Dec-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Bellis, RF: AUTHOR [+4]

Abstract

The purposes of this circuit are to sense the state of bits stored within the array and provide off-chip drive capability for the stored data, together with a chip select/deselect function. The array circuits of a high speed ROS are designed to operate with very small voltage transitions to achieve the required performance. This means that the sense circuit must be capable of detecting the state of a stored bit where a small voltage change represents a transition from a zero to a one state. The sense amplifier must also be temperature-compensated and provide tracking with circuits within the array as well as being immune to variations in power supply voltages. The sense amplifier T2 operates in the grounded base mode with base voltage supplied by temperature-compensated reference generator T1.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 69% of the total text.

Page 1 of 2

High Speed Sense Amplifier and Dual-Phase Output Circuit

The purposes of this circuit are to sense the state of bits stored within the array and provide off-chip drive capability for the stored data, together with a chip select/deselect function. The array circuits of a high speed ROS are designed to operate with very small voltage transitions to achieve the required performance. This means that the sense circuit must be capable of detecting the state of a stored bit where a small voltage change represents a transition from a zero to a one state. The sense amplifier must also be temperature-compensated and provide tracking with circuits within the array as well as being immune to variations in power supply voltages. The sense amplifier T2 operates in the grounded base mode with base voltage supplied by temperature-compensated reference generator T1. The values of resistors R1, R2 and R4 are critically chosen to function together with T1 to provide the correct proportion of Vb tracking to compensate for similar Vb variations within the array being sensed. Sense transistor T2 is SBD (Schottky barrier diode) clamped to prevent saturation, and is kept in a slightly conducting state during the off mode by bias resistor R3 to improve turn-on time. Biasing allows the sense amplifier to switch with a small voltage transition and less than 1 ma of current change at the emitter of T2. An emitter-follower current switch consisting of T3, T4, T5, T6 and constant current sour...