摘要:
A novel switched capacitor gain stage uses a unique circuit design and clocking technique that reduces the component mismatch offset voltage and the clock-induced feedthrough offset voltage produced by the circuit. The totalcapac- itance ratio between the input capacitors and the feedback capacitor necessary to achieve a desired total gain is also minimized.
摘要:
Structure de semi-conducteur possédant au moins trois types de puits (65, 68, 71) qui peuvent présenter différents niveaux de dopage, et procédés de fabricaton d'une telle structure. Dans un procédé, les régions qui deviendront des dispositifs actifs sont protégées par une couche de nitrure (62) lors de l'implantation des régions de puits associées (65, 68, 71). Dans une variante, des puits implantés au préalable sont recouverts d'une épaisse couche d'oxyde (66, 69) laquelle, en combinaison avec la couche de nitrure (62) produit un alignement automatique des puits adjacents. Dans une autre variante, les puits implantés sont recouverts d'oxyde (66) alors qu'un dernier puits est implanté en étant défini par une épaisse couche d'oxyde (66) et par une photoréserve (67a). Tous les procédés éliminent une étape de masquage et le besoin d'aligner le bord d'un masque de photoréserve successif avec le bord d'un masque de photoréserve précédent. Les structures ainsi formées peuvent présenter des puits P fortement dopés, des puits N fortement dopés, et des puits P ou N légèrement dopés, ou les deux, ce qui permet de former sur la même puce des dispositifs à tension de claquage élevée et de dispositifs à basse tension de claquage.
摘要:
In order to protect, from unauthorised copying, computer code placed in internal circuitry in a computer, an encoding Exclusive-OR gate (23) is provided in the computer for each data transmission lead (8) from the respective circuitry. One input lead of each encoding Exclusive-OR gate is connected to the corresponding incoming data transmission lead (7) in order to receive data to be transmitted on accessible data lines. The other input lead of each encoding Exclusive-OR gate is connected via a code matrix (22) to a source (11) of a random M-bit binary number. The output signal provided by each Exclusive-OR gate (23) is the encoded data bit which Is applied to one of the accessible data lines (8). The encoded data is decoded by a circuit similar to the encoding circuit. In the decoding circuit a decoding Exclusive-OR gate (33) is provided for each data transmission lead (9). One input lead of each decoding Exclusive-OR gate (33) is connected to an incoming encoded data transmission lead (8). The other input lead to the decoding Exclusive-OR gate (33) is connected via a code matrix (32) which is similar to the code matrix (22) provided in the encoding circuit, to a source (II) of a random M-bit binary number, where the M-bit binary number is the same M-bit binary number provided in the encoding circuit. The output leads of the decoding Exclusive-OR gates (9) are the transmission lines which carry the decoded data. The encoding matrix (22, 32) and the random M-bit word are the same in the encoding and decoding circuit, so the data on the output leads of the Exclusive-OR gates is properly decoded. However, the data on bus lines running between integrated circuits, and which therefore may be intercepted through the use of logic probes, is in encoded form, thereby. substantially increasing the effort required to illicitly determine the data stored.
摘要:
An array of MOS transistors (30) formed in a semiconductor substrate having a plurality of continuous diffused lines (bit lines) (7-3, 7-4, 7-5 and 7-6) serving as the source and drain regions of a plurality of MOS transistors. A plurality of conductive word lines (33, 133) are formed over the plurality of diffused lines, crossing the diffused lines at substantially right angles, with each conductive word line serving as the gates of a plurality of MOS transistors. Each transistor of the memory array is formed in a region containing two continuous diffused lines and a single word line. A single electrical contact (36-3, 4, 5, 6) to a bit line is formed for each such diffused line.
摘要:
A differential operational amplifier is provided with a feedback loop which continuously adjusts the common mode voltage level of the amplifier so that it lies in the center of the dynamic range of the amplifier. The feedback loop measures the instantaneous common mode voltage level and compares it with a reference voltage which is set to reflect the desired common mode voltage. An error signal is generated and fed back into the amplifier to adjust the instantaneous common mode voltage level towards the reference level. Frequency compensation is also provided to overcome the phase shift introduced by the use of RC networks.
摘要:
A late mask programming process is provided for factory programmed ROMs or logic circuitry. MOS transistors functioning as ROM cells or in logic circuitry are fabricated by a standard MOS Process. Then, a thin stop layer of silicon nitride is provided over the transistors and followed by a layer of silicon dioxide. Programming is accomplished by applying a program mask and etching through the layers overlying the gate regions of selected transistors down to the silicon nitride stop layer. The silicon nitride stop layer prevents overetching and shorting of the gates. Then, ions are implanted underneath the gates of the selected MOS transistors to alter their threshold so, for example, as ROM cells they signify a different state than those cells whose transistor gates are not implanted with ions. The silicon nitride layer serves to stop the etch solution but permits the ions to pass through, penetrate the substrate and raise the thresholds of the selected transistors. The silicon dioxide layer stops the ions from being implanted into the nonselected transistors.