摘要:
A two-level supply voltage detection circuit includes two power supply detection circuits. One of the power supply detection circuits is provided on the high potential side, and the other is provided on the lower potential side. Each power supply detection circuit outputs a detection signal which is active when the supply voltage is equal to or higher than a reference value. The two-level supply voltage detection circuit outputs an OR logic value of the detection outputs of the power supply detection circuits. Furthermore, the power supply detection circuit on the low voltage side includes a detection operation control circuit. Only when a detection signal output from the power supply detection circuit on the high voltage side is active, the detection operation control circuit turns off the power supply detection circuit on the low voltage side in response to the active detection signal.
摘要:
A bare-chip IP of a multi-chip module and an external device of the multi-chip module are interfaced with each other through a dedicated I/O bare-chip IP. Each of the bare-chip IPs other than the dedicated I/O bare-chip IP is not provided with an interface circuit for connection to the external device, and thus is only required to have a withstand voltage characteristic corresponding to the operating voltage of an internal circuit. As a result, it is only necessary to provide, on the bare-chip IPs, transistors of a few kinds of withstand voltage characteristics.
摘要:
Each bare-chip IP includes pad electrodes that are of the same size and shape, made of the same material, and arranged in an array at the same pitch over almost the entire surface thereof. A silicon wiring substrate includes pad electrodes that are arranged in an array over almost the entire surface thereof at the same pitch as that between the pad electrodes of the bare-chip IPs. The bare-chip IPs are mounted on the silicon wiring substrate, thereby making a multichip module.
摘要:
A power circuit including means for preventing the generation of an inrush current during the power circuit's initial operation without increasing the size of the power circuit is described. The power circuit comprises an output transistor for supplying a current from a power supply to an output terminal, and a differential amplifier for controlling the current supplied by the output transistor in such a manner as to regulate a voltage at the output terminal based on a preset reference voltage. A limiting transistor is provided as a source follower on a current path at the output stage of the differential amplifier. The gate potential of the output transistor is controlled using the source potential of the limiting transistor. Before the power circuit starts to operate, an operation controller charges a capacitor to control the gate potential of the limiting transistor so that during the initial operation of the power circuit, the capacitor is discharged by using a current source. Accordingly, during the initial operation of the power circuit, the gate potential of the limiting transistor gradually decreases while the gate-source voltage of the output transistor gradually increases. As a result, the generation of the inrush current can be suppressed.
摘要:
A current mirror circuit 10 is formed to have a current ratio (a transistor size ratio) of 1:m. As well, respective pairs of nMOS transistors MN1, MN3 and nMOS transistors MN2, MN4 are formed to have a current ratio of 1:m. Two currents output from the current mirror circuit 10 are each distributed to two. The distributed currents flowing in the nMOS transistors MN2, MN4 are added and are then allowed to flow into one resistor R2. Hence, for the resistor R2, only one resistor in which current of double flows suffices when m=1, for example. This effortlessly reduces the necessary resistance to one fourth.
摘要:
In a semiconductor integrated circuit of the present invention, the main circuit 2 includes MOS transistors in which the source and the substrate are separated from each other. The substrate potential control circuit 1 controls the substrate potential of the MOS transistors of the main circuit 2 so that the actual saturation current value of the MOS transistors of the main circuit 2 is equal to the target saturation current value Ids under the operating power supply voltage Vdd of the main circuit 2. Therefore, it is possible to suppress variations in the operation speed even if the operating power supply voltage of the semiconductor integrated circuit is reduced.
摘要:
A power supply voltage detection circuit includes a voltage division circuit for linearly dividing a power supply voltage, a reference voltage circuit for providing a reference voltage, and a comparison circuit for comparing the output voltage from the voltage division circuit and the reference voltage from the reference voltage circuit. The power supply voltage detection circuit outputs a signal upon detecting that the power supply voltage is equal to or higher than the reference voltage. A PMOS transistor is provided between the voltage division circuit and the comparison circuit. The PMOS transistor includes a source terminal connected to an output terminal of the voltage division circuit, a drain terminal connected to an input terminal of the comparison circuit, and a gate terminal connected to the ground. Until the output voltage from the comparison circuit is higher than the threshold voltage of the PMOS transistor, the PMOS transistor remains OFF, thereby canceling the input of the output voltage signal from the voltage division circuit to the comparison circuit. Thus, without using external components, the signal is prevented from being erroneously output due to the output voltage from the voltage division circuit rising over, without crossing, the reference voltage from the reference voltage circuit during a sharp rise of the power supply voltage.
摘要:
During an intermittent operation mode, a switch is normally opened and a capacitor with a large capacitance is isolated from a circuit. Under this condition, a power source voltage is intermittently supplied to a driven device. Since a charge/discharge current of the capacitor during the intermittent operation mode is limited to the charge/discharge current of the capacitor with a small capacitance, the power consumption can be lowered. In addition, since no switch exists in the current path from a power source voltage conversion circuit to the driven device, there is no drop, due to a switch, in the voltage supplied from the power source voltage conversion circuit to the driven device. On the other hand, during a continuous operation mode in which power source voltage is continuously provided to the driven device, the switch is normally closed and a capacitor with a large capacitance is connected to the power source system. Then the noise level in the supplied power is lowered.
摘要:
A cell library database includes function information of standard cells which are basic circuits forming a logical device, each of the standard cell comprising at least one of power supply terminal as logical terminals, the function information of the standard cell containing logical information or delay information of the power supply terminal relative to an output terminal, or function information of macro cells which are functional circuits forming a logical device, each of the macro cell comprising at least one of power supply terminals as logical terminals, the function information of the macro cell containing logical information or delay information of said power supply terminals relative to an output terminal. A design aiding system uses the cell library database to execute logical simulation, etc.
摘要:
The screen-input image display device has a touch panel for outputting touched locations of a finger or the like in contact with a display panel screen; and a sensing circuit for sensing coordinates of the touched locations based on the output of the touch panel. The touch panel has a transparent conductor film which is single layer on a transparent substrate, the transparent conductor film being patterned into numerous electrode pads arranged in rows and columns of a two-dimensional matrix, and surface areas of the electrode pads vary depending on the location of the touch areas. Coordinates of the touch locations are sensed based on the proportion of charge signals of the touch locations due to differences in surface areas of the electrode pads.