Browse Prior Art Database

Array On Chip Sense Amplifier

IP.com Disclosure Number: IPCOM000076452D
Original Publication Date: 1972-Mar-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Leung, H: AUTHOR [+4]

Abstract

Described is an array on-chip sense amplifier. Referring to Fig. 2, the line A is up during the full-select mode. This sets up the voltage on line VD. The current source is determined by transistor T4 with the current magnitude equal to V2-VD2 over R7.

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Array On Chip Sense Amplifier

Described is an array on-chip sense amplifier. Referring to Fig. 2, the line A is up during the full-select mode. This sets up the voltage on line VD. The current source is determined by transistor T4 with the current magnitude equal to V2-VD2 over R7.

Initially before any signal occurs, the bases of transistors T7 and T8 are at the same potential. However, due to the mismatch in the respective VBE's of transistors T7 and T8 or to differences in resistors R4 and R6, transistor T7 conducts less than transistor T8. The data-out current at the anode of diode D5 is a fraction (depending on the offset) of the total current source value.

When a signal arrives, the potentials at the bases of transistors T7, T8 change depending whether the signal is a "1" or "0". First, assume a 1 signal is being interrogated, then current flows in the IR path. This current lowers the potential at the base of transistor T9 and the base of transistor T6 is higher in potential than that of transistor T9. The base of transistor T7 is then higher in potential than that of transistor T8. The current will conduct through transistor T7 resulting in an output at the data-out terminal. The reverse operation occurs when a 0 signal is sensed.

Diodes D3 and D4 are used to prevent transistor T4 from saturating under worst-case conditions. Transistor T5 is used to turn on and off the conduction in diodes D3 and D4 so that no standby power is dissipated, since line A comes...