A low power consumption component which operate at a high frequency is provided by separating out those critical signal paths which acquire a higher voltage to operate below a maximum propagation delay requirement and operating the remainder of the devices of the component at a lower power supply to minimize overall power consumption of the component.

Method and structure for improving power consumption on a component while maintaining high operating frequency

A multiple output spread spectrum clock circuit is provided that reduces electromagnetic emissions when two different clocks operate at frequencies which overlap one another. Two such clock circuits (10 and 11) are controlled so as to introduce a phase difference between the clocks as they operate through their spread spectrum profiles. The 'best' phase differences are around 18%, or around 50%, between adjacent spectrum clock outputs. The phase difference can be controlled by starting the first clock (SSCGn1) (10) at one point in time, while temporarily delaying the start of the second clock (SSCGn2) (11) until the appropriate moment; alternatively, it can be controlled by starting both clocks at the same moment in time, however, SSCGn1 begins at one point in the spread spectrum profile, while SSCGn2 begins at a different point in its spread spectrum profile.

Method and apparatus for providing multiple spread spectrum clock generator circuits with overlapping output frequencies

In contrast with a known dynamic gate-level simulation method, a method of analyzing electromagnetic interference (an EMI analysis method) according to the present invention enables estimation of EMI noise, by means of calculating signal propagation of each node through use of the signal propagation probability technique, and calculating variation time of each node through use of “the Static timing analysis technique”. In short, the present invention is characterized in calculating a frequency characteristic from the relationship between toggle probability of each node and delay in each node.

Method of analyzing electromagnetic interference

A method of suppressing noise in a circuit (302) is disclosed. The method comprises providing a supply voltage (Vcc) to a first terminal (312) of the circuit; (302) providing a ground voltage to a second terminal (314) of the circuit; providing a clock signal to the circuit; and actively decoupling noise from at least one of the first terminal (312) and the second terminal (314) of the circuit (302) by actively decoupling noise synchronously with the clock signal. A circuit for suppressing noise in a circuit (302) is also disclosed.

Method of and circuit for suppressing noise in a circuit

A semiconductor device 100 has a peripheral cell region 102 and an internal cell region. The peripheral cell region is provided with a signal input terminal 110 that inputs input signals having different voltage levels in a normal operation mode and in a test mode starting time; a first transmission circuit 120 that provides the input signal to the internal cell region; and a second transmission circuit 150 that outputs a control signal indicating a test mode when the input signal has a voltage level equivalent to a voltage to be provided when the test mode is started. Also, a control circuit 180 that cuts off current that flows in the second transmission circuit 150 when the input signal has a voltage level to be provided in the normal operation mode. The control circuit 180 includes first and second P-type transistors 182 and 184 formed in a floating N-type well.

Semiconductor device and electronic apparatus using the same

A circuit is provided that reduces the electromagnetic emissions from an integrated circuit. The circuit includes the resistive portion of an intrinsic low pass filter network and a means for modulating the resistance in response to switching of the integrated circuit nucleus logic elements. The resistance is increased before the nucleus logic elements switch and is gradually decreased upon completion of all switching of the nucleus logic elements. A portion of the transient switching pulse waveform, normally provided by the external power supply, is instead provided by the intrinsic nucleus capacitance associated with the nucleus logic. In particular the high frequency components are sourced by the intrinsic nucleus capacitance. The amplitude and the rise time of the transient switching pulse is thereby reduced. Further reduction in electromagnetic emission is provided by modified output buffers where transient switching waveforms are reduced by current limiting the output switching transistors and providing initial transient current from the intrinsic capacitance associated with the output buffer.

Integrated circuit having reduced electromagnetic emissions an integrated circuit including a variable impedance for reduced electromagnetic emission

A circuit is provided that reduces the electromagnetic emissions from an integrated circuit. The circuit includes the resistive portion of an intrinsic low pass filter network (26) and a means for modulating the resistance in response to switching of the integrated circuit nucleus logic elements. The resistance is increased before the nucleus logic elements switch and is gradually decreased upon completion of all switching of the nucleus logic elements. A portion of the transient switching pulse waveform, normally provided by the external power supply, is instead provided by the intrinsic nucleus capacitance (25) associated with the nucleus logic. In particular the high frequency components are sourced by the intrinsic nucleus capacitance (23). The amplitude and the rise time of the transient switching pulse is thereby reduced. Further reduction in electromagnetic emission is provided by modified output buffers (32) where transient switching waveforms are reduced by current limiting the output switching transistors and providing initial transient current from the intrinsic capacitance associated with the output buffer.

Gordon L. Mortensen

Papers

Integrated circuit having reduced electromagnetic emissions an integrated circuit including a variable impedance for reduced electromagnetic emission

Integrated circuit having reduced electromagnetic emissions