Showing papers by "STMicroelectronics published in 1975"

Clock generator and delay stage

Abstract: A clock generator for an MOSFET integrated circuit having a plurality of cascaded delay stages is disclosed. Each delay stage includes a bootstrap inverter having first and second transistors connected in series between the drain supply voltage and a source supply voltage, thus forming a first node between the transistors. The first node is capacitively coupled to a bootstrap node which is connected to the gate of the first transistor. The bootstrap node is also coupled through the channel of a third transistor to an input. The gate of the third transistor forms a third node. Circuit means are provided for precharging the third node and then isolating the third node while an input signal is applied through the third transistor to the bootstrap node so that the third node is also bootstrapped up to permit rapid charging of the bootstrap node to the full voltage of the input signal. The second transistor is held on by a precharge signal so that the first node is held low until the bootstrap node has been charged to the input voltage. Then both the third node and the gate of the second transistor are discharged to turn the second and third transistors off, thus permitting the bootstrap node to go rapidly above the drain supply voltage. The bootstrap node may be used directly as output, or can drive the gate of an output transistor so as to produce a very rapidly rising output which quickly reaches the full drain supply voltage. Circuit means is also provided to discharge the third node to disable the output before an input signal occurs. Since the third node is automatically discharged after receiving an input, the input may subsequently be changed without changing the output. Circuit means is also provided to selectively discharge the bootstrap node to isolate the output after it has achieved maximum voltage, so that the output can be capacitively boosted above the drain supply voltage. A circuit is also provided to reset the output to zero volts in conjunction with isolation of the output. A clock generator employing the various functions of a plurality of cascaded delay stages is also disclosed to demonstrate the capabilities of producing a series of clock pulses which go to V DD in timed sequence in response to input signal, of producing a voltage substantially above V DD , and of producing a pulse of predetermined duration.

MOSFET Memory chip with single decoder and bi-level interconnect lines

Abstract: A dynamic random access read/write memory having 4,096 binary storage cells is disclosed. The system utilizes a single set of six address input buffers and one decoder for both row and column address information. The memory array includes two 32×64 arrays of dynamic storage cells separated by a row of 64 sense amplifiers each having split sense buses or digit lines extending to each column of memory bits. The decoders are disposed along one edge of the array which is at right angles to the row of sense amplifiers. The column enable lines from the decoders extend through the memory array between parallel row enable lines and then turn and proceed as a different level of interconnect between parallel digit lines to select the addressed sense amplifiers. Each column enable line enables two sense amplifiers which simultaneously read data from two cells of the addressed row. The least significant bit of the six column address inputs is used to make the final one out of two selection of the sense amplifier and thus the cell from which data is to be read or in which data is to be written. The decoder includes circuit means for storing the decode signal identifying a selected row while subsequent column address signals are input to the chip and decoded by the same decoder. Row address data is first input through the six address pins to the chip; the six inputs are sampled and latched in six address buffers; and the six address inputs are then decoded so that a single row enable line is selected and held active dynamically. Then while data is read from all storage cells in the active row by the sense amplifiers, column address signals applied to the same input pins for the chip are sampled and latched in the same six address buffers, and decoded by the same decoder to select and hold a column enable line active.