摘要:
A data transfer circuit is provided for sending digital data at high rates across short but significant distances within an integrated circuit. The data is sent on parallel conductors that are divided into a number of groups. At the receiving end, a multiplexer selects each of the groups in turn and presents them at a set of conductors that are the same in number as one of the groups. At the transmitting end, a data marshalling circuit takes the bitstream to be transmitted and places it on the conductors in a particular redundant fashion so that the bitstream appears to advance across the set of outputs of the multiplexer. That is particularly useful where those outputs are presented to a pre-emphasis filter and line driver. The apparent data rate can be changed by making two or more of the groups of conductors have identical data.
摘要:
There is provided a power supply monitor circuit comprising a positive supply monitoring input, a negative supply monitoring input, and a voltage divider connected between the positive and negative supply monitoring inputs and having an intermediate node providing a potential intermediate those on the positive and negative supply monitoring inputs. A sampling circuit is connected to sample the potential at each of the positive supply input the negative supply input and the intermediate node. Also provided is a method of monitoring noise on a power supply whereby phase information from those samples is derived about the noise signals at the two said points.
摘要:
The present invention provides a support grid having the form of a web of vertically disposed plates said web of plates comprising (a) a network of strands of plate segments connected by junctions, the said strands terminating only at the periphery of the grid, and (b) one or more internal plate branches, each plate segment being joined at one end to a junction with at least two other plate segments and at the other end either being joined to a junction with at least two other plate segments or terminating at or near C the periphery of the grid, said internal branch comprising a plate having a free end within the grid and being joined at one end thereof to a segment or to another branch, characterised in that in horizontal cross-section through the grid each segment has at least two angular and/or curved portions which alternate in direction.
摘要:
There is described a semiconductor switch device having two semiconductor components, the first component receiving drive signals from the second. The first component contains either a single power bipolar switch element for single ended control of the energisation of a load or a bridge of such elements enabling energisation of a load with different polarities. The switch elements, which may be transistors or darlington multiple transistors, have voltage dropping elements connected in the leads to their control bases, so that the drive signals from the second component can be produced by low impedance connection to one or the other supply conductor, thereby keeping the power dissipation of the second component to a low value. The voltage dropping elements may be a series resistor or a constant current circuit. The first component may have a temperature sensitive member, such as a diode, for diverting current from the control base of the or each switching element to terminate its conduction if the temperature of the component becomes too high. The switch device is used in a switching system for a motor vehicle, for example, where central control is required of a plurality of loads at various locations. A central controller transmits coded control signals to local controllers which direct the control signals to the correct switch devices. Status signals representing the functional states of the loads and the outputs of local sensors are sent to the central controller to produce there a corresponding display.
摘要:
To provide an integrated circuit with protection against overvoltage and overcurrent conditions, the channel of a field effect transistor is connected between the d.c. supply conductor for the integrated circuit and a further conductor for connection to one pole of a d.c. source for the circuit. The channel of the transistor is provided by a region of an epitaxial layer on a substrate of opposite conductivity type which provides a back gate for the transistor. A conductor is provided for connecting the substrate to the other pole of the d.c. source. The d.c. supply line voltage for the integrated circuit is thereby limited to the pinch-off voltage of the field effect transistor and the power supply current is limited to the zero gate-bias drain current of the field effect transistor. A protection arrangement also is disclosed for limiting forward current flow through an isolation diode in an integrated circuit resulting from accidental reverse polarity connection of a d.c. source to the circuit. The isolation diode is connected to the d.c. supply conductor only through a path including a current limiting resistor. A circuit combining both protection features also is described, the protection resistor connecting one end of the field effect transistor channel to the conductor for connection to the d.c. supply source to limit forward current flow through the diode junction between the transistor channel region and the substrate back gate region resulting from accidental reverse polarity connection of a d.c. source for the circuit.
摘要:
A transducer apparatus wherein the source to drain conductance of an insulated gate semiconductor field effect device is modulated by the application of mechanical stress to the channel layer of the device. Specific transducer modifications include microphone pickups and phonopickups. The pickup may include preamplifiers in either discrete or integrated circuit form.
摘要:
A data transfer circuit is provided for sending digital data at high rates across short but significant distances within an integrated circuit. The data is sent on parallel conductors that are divided into a number of groups. At the receiving end, a multiplexer selects each of the groups in turn and presents them at a set of conductors that are the same in number as one of the groups. At the transmitting end, a data marshalling circuit takes the bitstream to be transmitted and places it on the conductors in a particular redundant fashion so that the bitstream appears to advance across the set of outputs of the multiplexer. That is particularly useful where those outputs are presented to a pre-emphasis filter and line driver. The apparent data rate can be changed by making two or more of the groups of conductors have identical data.
摘要:
A driver amplifier for a bus feeds single polarity signals of controlled slew rate to the bus. The slew rate control is effected by a feedback capacitor connected from the output to the input of the amplifier. A clamp is provided for selectively connecting the input of the amplifier through a low impedance path to a point of reference voltage so that when the amplifier is quiescent signals on the bus cannot be fed through the capacitor to turn on the amplifier. A current source and a switchable current sink are connected to the input of the amplifier to change the capacitor to produce the slew rate controlled transitions. Another driver amplifier of the same design but using components of the opposite conductivity type can be used to apply signals of the opposite polarity to the same bus.
摘要:
A reference circuit. Included are first and second reference circuit blocks, first and second controllable current sources connected to supply current through the first and second reference circuit blocks respectively, an amplifier having non-inverting and inverting inputs responsive to the voltages developed by the first and second reference circuit blocks respectively and having an output connected to control the currents provided by the first and second current sources, and an output stage having a reference output controlled by the output of the amplifier. The reference circuit further comprises start-up circuitry, including a latch having an output indicating its state and being responsive to a signal indicative of the output from the reference output to latch from a first state into a second state when that signal passes a first threshold, and a switch that is responsive to the output of the latch to supply a control signal.
摘要:
The present invention relates to pre-distortion in transmitter circuits and provides a circuit for introducing pre-distortion into the output of a transmitter, wherein said pre-distortion comprises a pre-cursor, a cursor and a post-cursor, the circuit comprising: a first driver arranged to switch an output drive between said pre-cursor and said cursor; a second driver arranged to switch an output drive between said post-cursor and said cursor; a third driver arranged to switch an output drive between a positive cursor drive and a negative cursor drive. The arrangement provided give flexibility when setting the pre-cursor, cursor and post-cursor levels.