Abstract: A digital frequency detection circuit, or frequency discriminator, is implemented for use as a synchronization field detector for the synchronization field frequency in the data stream read from a computer floppy disk. No analog components are utilized; and the detector produces an output indicative of the presence of a valid synchronization field frequency whenever the incoming data pulses fall within a predetermined range of frequencies having a lowest frequency limit and an upper frequency limit. This is accomplished by employing a multi-stage binary counter for counting the reference clock pulses from a computer. The counter is reset each time an incoming data pulse is received; and the outputs of the counter are coupled to coincidence gates, which establish the lowest and highest frequency limits of the predetermined range of frequencies to be detected.

Abstract: A level-shifter circuit includes a deep N-tank to insulate the N-channel portions of transistors from the substrate. The circuit is formed on a P-type substrate coupled to reference voltage Vss. A first field-effect transistor has first and second N+ doped regions formed in a third isolating P- doped region. The third doped region is formed in a fourth isolating N- doped region, which is formed in the substrate. A second transistor has first and second N+ doped regions formed in the same isolation regions as those of the first transistor. A third field-effect transistor has first and second P+ doped regions formed in an isolating N- region that is formed in the substrate. A fourth field-effect transistor has first and second N+ doped regions formed in the same isolation N- region as that of the third transistor. The gate of the first transistor is coupled to a first input.

Abstract: The present invention relates to a substrate voltage generator for a semiconductor device, comprising an oscillator for generating an oscillating signal to compensate the resistance value with temperature, a voltage pump driver for providing clock signals, a voltage pump for generating substate voltage, a level detector for detecting the substrate voltage, and a oscillating driver for providing the bias voltage, wherein the power consumption in the standby state of semiconductor devices can be reduced and the driving capacity is not variable even though the temperature is changed.

Abstract: A residual charge removing circuit connected to a node in a power-on reset pulse generating circuit for removing positive charges which remain in this node when a power supply is turned off is disclosed. This residual charge removing circuit is formed of two N-channel MOS transistors connected in series between the node and the ground, and one capacitor. Out of the two N-channel MOS transistors, the transistor near the node has a grounded gate. The capacitor is connected between a gate of the transistor, out of the two N-channel MOS transistors, which is distant from the node, and a power supply. The gate of the transistor distant from the node is connected to a connection point between the two N-channel MOS transistors. Therefore, when a supply potential lowers below a threshold voltage Vth of the MOS transistors due to the power-off, the transistor distant from the node is turned off, so that a potential of the connection point becomes -Vth owing to a discharge of negative charges from the capacitor.

Abstract: Capacitance compensation techniques are used to reduce capacitive effects that impact on the performance of current steering circuits (FIG. 1). In an isolation technique (FIGS. 2a-2e), a resistor (R) or a diode (D) is coupled to a data-switched transistor to dampen voltage perturbations associated with the gate-to-source capacitance. In a design variable technique FIGS. 3a-3d), a transistor (PDV) is included in either the output or ground legs of the current steering circuit to provide a design variable to counteract the capacitive effects of the associated data-switched (PDX/NDX) or voltage-controlled (PREF) transistor. In a bipolar substitution technique (FIG. 4), a data-switched bipolar transistor (QDX) is substituted for the data-switched MOS transistor, and made sufficiently small to significantly reduce junction capacitance. In addition, capacitive effects can be reduced by introducing fabrication alterations (FIGS.

Abstract: A semiconductor memory device having a substrate voltage production circuit comprises a time delay circuit. The time delay circuit of the present invention has a simple construction and is provided to facilitate removal of an unwanted substrate current I.sub.SUB existing during a precharge cycle of memory operation. The substrate voltage production circuit requires no additional regulating signals for operation. Latch-up conditions commonly caused by such unwanted substrate currents are eliminated and stable semiconductor memory device operation is achieved.

Abstract: A driving circuit for driving a floating circuit (28) responsive to a digital signal (IN) includes two DMOS transistors (10, 12) which are driven in opposite phase on their respective gates starting from the digital signal. The two DMOS transistors are biased by a current source which is formed by a current mirror (16, 18), which mirrors a reference current (I.sub.BIAS), and by an auxiliary circuit (34-44) for injecting an additional current pulse during switching. Two MOS transistors (20, 22) serve as the respective loads for the two DMOS transistors. The MOS transistors can be P-channel transistors, in which event the gate of each MOS transistor (20, 22) can be connected to the drain of the other MOS transistor. Two Zener diodes (24, 26) can be employed to limit the voltage between the gate and source of the respective MOS transistor. The driving output of the floating circuit (28) can be the drain of one of the DMOS transistors.

Abstract: A circuit for providing a glitch-proof, powered-down inactive state to a memory array is disclosed. Cross-coupled NAND gates provide non-overlapping true/complement outputs for an on-chip receiver. Stable inactivation of both true and complement outputs is ensured without performance degrading delay stages.

Abstract: A semiconductor integrated circuit device having an analogue signal processing circuit and a digital signal processing circuit formed on a single semiconductor substrate is disclosed. As an example of the analogue signal processing circuit, a voltage comparator is described. Being liable to be affected by noise, an inverter 2 is formed of an NMOS transistor 41 and a resistance R. For transistor 41 is formed in a well region having a conductivity type (p) opposite to the conductivity type of the substrate (n), it is not easily influenced by noise transmitted through the substrate. Therefore, a voltage comparator independent of the adverse effect of noise from the digital signal processing circuit is obtained.

Abstract: An updown counter up-counts binary data stored in respective flip-flops in an up-count mode, and down-counts the binary data stored in the respective flip-flops in a down-count mode. When a command for an up-count mode is applied by an up/down control signal, the binary data stored in the respective flip-flops is converted into a complement on two after converting it into a complement on one. When a command for a down-count mode is applied by an up/down control signal, the binary data stored in the respective flip-flops is converted into a complement on one after converting it into a complement on two. The converted data is used to rewrite the data stored in the respective flip-flops.

Abstract: A clock alignment circuit is responsive to a high speed clock signal for generating a low speed clock signal. A clock generator circuit monitors the phase difference between the high speed clock signal and the low speed clock signal and develops a control signal in response thereto during a time slot window signal for adjusting the transitions of the low speed clock signal to align with the high speed clock signal. The clock generator circuit is placed in the vicinity of the associated utilization circuit to that the low speed and high speed clock signals maintain alignment.

Abstract: An output of a power-on-reset (POR) circuit is coupled to another circuit which needs to have the logic states thereof reset during each time a power supply used to power same is switched on. The POR circuit includes a first input circuit for generating an output signal that tracks the power supply output voltage Vdd approximately a first predetermined threshold below Vdd, as Vdd ramps up and further includes a second input circuit which generates an output signal which tracks approximately a second predetermined threshold above a second fixed voltage level, e.g., ground. The POR circuit further includes a comparator which compares the output signals from the first and second input circuits and switches an output signal thereof from a first to a second logic state once the input circuit output signals cross each other. A buffer is typically coupled to the output of the comparator to limit loading on same so as not to affect the comparator switching point.

Abstract: A signal transmission circuit which transmits a signal over a transmission line includes a line driver circuit comprising a differential amplifier and an emitter follower circuit connected thereto, and a metal oxide semiconductor field-effect transistor which provides a high impedance when power supply from a power supply source is turned off and, thereby, causes the line driver circuit to provide a high output impedance to the transmission line when power supply is turned off.

Abstract: An uninterrupted event-time recorder enables high-precision measurements of the time-of-occurrence of randomly- and rapidly-occurring, digitally specified events such as the leading and/or trailing edges of asynchronous pulses. The lowest order binary digits of the recorder are constructed of high-speed synchronous integrated circuit counter devices. For an N-bit timer having M low-order bits, the highest order (N-M) bit counting is executed by two parallel (N-M)-bit slow-speed counters, one of which is incremented by the terminal count of the M-bit high-speed counter and the other which is incremented by the most significant bit (MSb) of the M-bit counter. The (N-M)-bit counters are read out through a multiplexer controlled by the MSb.

Abstract: Dummy power source wirings connected to a power source wiring are arranged in empty regions among the signal wirings that cross the clock wirings, the dummy power source wirings being arranged over or under the clock wirings in a manner to cross the clock wirings. The dummy power source wirings are formed to equalize the capacitances of the wirings whose lengths should be equalized among, for example, the clock distributing circuits or among the clock drivers.

Abstract: A pulse control circuit generates latch signals in response to edges of externally-input pulses and generates a resetting signal after each of the latch signals is generated. A pulse position measurement counter counts reference clock signals, thereby measuring the time interval between the generation of one latch signal and the generation of the succeeding latch signal. In response to the latch signal, a latch circuit latches the time interval measured by the pulse position measurement counter as output data. A pulse detector detects that the time interval between successive latch signals is shorter than a predetermined time. It also detects that the number of latch signals which have been input is larger than a predetermined number. A data control circuit is employed in association with the pulse detector.

Abstract: Disclosed is a sense amplifier employing an emitter coupled logic (ECL) circuit. A constant voltage generating circuit independent of a change or a fluctuation of a power supply voltage level is provided. Two current-mirror circuits supply constant currents to the ECL circuit based on a generated constant voltage. Since a constant current independent of the change of power supply voltage level is supplied to the ECL circuit, the ECL circuit reliably converts a small potential difference generated between I/O lines into a current signal. Accordingly, no erroneous reading operation is performed.

Abstract: A controlled slew rate buffer is disclosed which comprises a driver receiving voltage along a voltage supply line and includes feedback apparatus which senses the noise level along the voltage supply line and slows the speed of the buffer when the noise level passes a given threshold. The driver comprises at least one of (1) first and second VSS voltage sources and (2) first and second VDD voltage sources.

Abstract: A power-on-reset circuit includes first to third first-conductive-type MOSFETs, a second-conductive-type MOSFET, a capacitance, and first to third resistances. In the power-on-reset circuit, whether a reset signal is supplied to an external circuit is determined by threshold voltages of the MOSFETs and independent on the building-up speed of the power supply voltage.

Abstract: An electrical assembly including a digital logic circuit, an analogue processing circuit and an analogue power circuit is connected to test equipment. Test data from the equipment is supplied to the circuits via a shift register divided into three serial portions. One portion is connected between the digital circuit and the processing circuit, another portion is connected between the processing circuit and the power circuit, the final portion being connected at the output of the power circuit. The portions can isolate the circuits from each other and supply test data to the circuit under test. The test data output from the circuit is clocked along the register to its output.