The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 04, 1985
Filed:
Sep. 02, 1982
Klaus Heuber, Boblingen, DE;
Siegfried K Wiedmann, Stuttgart, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method of and a circuit arrangement for reading an integrated MTL(I.sup.2 L) store are described, wherein prior to or during a read operation, line capacities are discharged and in addition to the word line drivers and the bit line drivers, a read/write circuit is provided. Simultaneously with the selection of a word line (WL) or with a slight time delay (t1), two identical current sources (IRD0) are connected by means of two switches (S0 and S1) to the relevant bit lines (B0 and B1). As a result, the two injectors of the two bit line PNP transistors (T1 and T4) are supplied with the same currents. In a second phase (t2), the current sources (IRD0) are switched off so that the duration of the second time phase (t2) considerably exceeds the storage time constant (.tau.e) of the bit line PNP transistor (T4) connected to the switched 'OFF' NPN transistor (T3) of a cell. The effective storage time constant (.tau.SAT) of the bit line PNP transistor (T1 ), connected to the switched on NPN cell transistor (T2), considerably exceeds the storage time constant (.tau.e). As a result of the different time constants (.tau.e and .tau.SAT), the two storage charges (Q1 and Q4) are discharged at different rates during the third phase (t3), thus generating a very fast and high output signal (.DELTA.VBL=VS).