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Low Stand By Power Word Driver Circuit

IP.com Disclosure Number: IPCOM000090479D
Original Publication Date: 1969-Apr-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Wiedmann, SK: AUTHOR

Abstract

The circuit includes series-connected transistors T1 and T2. The base of T2 is fed, through input 8, with the chip select signal. The output signal from decoder D6 is applied to the base of T1. An increased current flow via the transistors to memory cell 7 is prevented through the simultaneous presence of a chip select and a decoder signal.

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Low Stand By Power Word Driver Circuit

The circuit includes series-connected transistors T1 and T2. The base of T2 is fed, through input 8, with the chip select signal. The output signal from decoder D6 is applied to the base of T1. An increased current flow via the transistors to memory cell 7 is prevented through the simultaneous presence of a chip select and a decoder signal.

In the stand-by state, no signal is applied to input 8. T2 is blocked, thus preventing collector current from flowing through driver T1 to several word drivers. The emitter-base junction of T1 acts as a normal diode so that the stand-by current from cell 7 flows from +V2 via resistor 5 and the diode path of T1.

Selection of the chip by a positive pulse on input 8 causes T2 to change to its conductive state. When all inputs of D6 have a positive potential, the D6 output emits a signal and the base potential of T1 rises. The base current Iw/beta, beta being the current amplification factor in common emitter circuit, necessary for controlling T1 is substantially less than the stand-by current of a word. The base potential of T1 of the nonaddressed words is kept so low by the potential of the D6 signal that only stand-by current is permitted to flow. The following characteristics of the circuit are advantageous. No special resistance is required for applying the word stand-by current of a memory cell 7. The power loss in the stand-by state is considerably reduced since the individual word dri...