Abstract: A class D amplifier is provided that is capable of reducing distortion of a specific sampling frequency, and frequencies that are multiples of this frequency to a level where an LPF is not required and small-scale control circuit. Class D amplifier 100 is provided with H (full) bridge output section 120, output control section 110 that is configured with random number generator 103 that takes individual random numbers that do not depend on input values as output values, and PWM control signal generating circuit 104 that generates a final PWM control signal from the input values and output values of random number generator 103. Output control section 110 divides a pulse signal outputted at a reference point between sampling frequencies into a plurality of pulse signals with random widths that do not include the reference point, and outputs the pulse signals with random widths.

Abstract: A high-precision and high-performance level shift circuit, which is not adversely influenced by an offset error owned by an operational amplifier. Two sets of resistors (4o) and (4p) having the same resistance values, which are connected between differential output terminals and an operational amplifier (4r) for performing a level shift control are provided. A feedback operation is carried out in such a manner that an average voltage of each of differential outputs (4i) and (4m) is continuously made coincident with a DC reference potential (4q) irrespective of an offset error of an output-purpose operational amplifier, and a level shift function having a small error is realized. Two resistors (4h and 4l) are series-connected between a differential output of a digital/analog converter (4a) and a level shift circuit to output a voltage outside an output dynamic range of the digital/analog converter (4a).

Abstract: A high-precision and high-performance level shift circuit is provided, which is not adversely influenced by an offset error owned by an operational amplifier, and an output dynamic range of a digital/analog converter of a signal source.

Abstract: In a cell library database, timing verification is conducted on an LSI which exists in a variable power supply system capable of changing the source voltage arbitrarily and which includes logic delay information associated with a plurality of source voltages. The database is configured, for example, so that the voltage information V of the source is represented in multiple bits V [1:0] and delay times Alh (Vlh) to Bhl (Vhh) between the time input signals A and B are each changed and the time the output signal Y changes are described for respective pieces of source voltage information LH (1.2 V), HL (1.5 V) and HH (1.8 V). This allows timing verification in the variable source system which operates with the source voltage changed dynamically.

Abstract: A method of growing compound semiconductor epitaxial layer by an atomic layer epitaxy, comprises the steps of blowing on a predetermined surface a compound source material gas constituted by atoms having an ion polarity different from atoms constituting the predetermined surface so that the compound source material is adsorped on the predetermined surface in a non-decomposed state, and decomposing the adsorped compound source material on the predetermined surface into atoms constituting crystals at the predetermined surface so as to grow an atomic layer of atoms having the same ion polarity as the compound source material gas. The ion polarity of the atomic layer prevents adsorption of the compound source material after the atomic layer is grown.

Abstract: A method of growing a group III-V compound semiconductor epitaxial layer on a substrate by use of atomic layer epitaxy grows an aluminum layer on one of {100}, (111)B, ( 111)B, (111)B, and (111)B planes of the substrate by supplying a quantity of aluminum amounting to at least two times a surface density in a group III-V compound semiconductor epitaxial layer or grows an aluminum layer on one of {110} planes of the substrate by supplying a quantity of aluminum amounting to at least three times the surface density in the group III-V compound semiconductor epitaxial layer, and grows a layer of a group V material on the aluminum layer by supplying a quantity of the group V material amounting to at least two or three times a surface density in the group III-V compound semiconductor epitaxial layer. The layer of the group V material and the aluminum layer constituting the group III-V compound semiconductor epitaxial layer.