Abstract: The semiconductor device may include, but is not limited to, a first switching circuit, a second switching circuit, and a control circuit. The first switching circuit switches between first and second states. The second switching circuit switches between the first and second states. The second switching circuit reduces a first power impedance across the first switching circuit. The control circuit is coupled to the first and second switching circuits. The control circuit keeps the first switching circuit in the first state. The control circuit switches the second switching circuit from the second state to the first state.

Abstract: In a receiver circuit that receives data and clock signals through the cables, the number of transitions of a signal obtained based on the data or clock signal is detected by a frequency detection circuit, and when the number of transitions is not more than a predetermined set value, a signal for resetting the operation of a serial-parallel converter circuit included in a data processing unit is output, so as to control the output of received data. Thus, disconnection of the cable can be detected with low power consumption without providing a pull-up resistor and pull-down resistor and noise resistance can be improved.

Abstract: A device is provided for managing the current consumption peak on each powering-up of a domain in an electronic circuit. A plurality of domains are present and a global power supply grid provides power. Each domain is selectively supplied by a local supply grid connected to the global supply grid via a plurality of commanded switch transistors. A pre-charge transistor is used to pre-charge a domain at powering-up. A command circuit controls operation of the switch transistors through an analog command signal whose slew rate is controlled to ensure that switch transistor conduction is delayed to enable the pre-charge circuit to charge the domain to a sufficient degree that activation of the switch transistor will not draw excessive current.

Abstract: On-die-termination control circuit includes a mode detecting unit for detecting a power-down mode and a power-down delay configured to delay an on/off control signal in the power-down mode. On-die-termination control circuit provided a shift register configured to delay an on/off control signal in synchronization with shift clocks in a non-power-down mode, and transfer the on/off control signal as received without delay in a power-down mode, a power-down delay configured to delay the on/off control signal in the power-down mode, and not to delay the on/off control signal in the non-power-down mode and a controller configured to control enabling/disabling of an on-die-termination operation according to information about enable/disable timing of an on-die-termination operation provided by the on/off control signal that have passed through the shift register and the power-down delay.

Abstract: A circuit having dynamically controllable power. The circuit comprises a plurality of pipelined stages, each of the pipelined stages comprising two clocking domains, a plurality of switching circuits, each switching circuit being connected to one of the pipelined stages, first and second power sources connected to each of the plurality of pipelined stages through the switching circuits, the first power source supplying a first voltage and the second power source supplying a second voltage, wherein the first and second power sources each may be applied to a pipelined stage independently of other pipelined stages, first and second complementary clocks, and a plurality of latches connected to the first and second complementary clocks and to the plurality of pipelined stages for proving latch-based clocking to control the first and second clocking domains and to enable time-borrowing across the plurality of switching circuits.

Abstract: Data transmitter includes a first and second output nodes terminated to a first level, a controller configured to generate an off signal that is activated by logically combining first and second data during a low-power mode, a first driver configured to drive the first or second output node to a second level in response to the first data and a second driver configured to drive the first or second output node to the second level with a driving force different from that of the first driver in response to the second data, the second driver being turned off when the off signal is activated.

Abstract: A voltage supply control circuit is arranged between a true ground voltage and a pseudo ground line. In an active mode, first and second control signals are at the “H” and “L” levels, respectively. In response to this, a first switch is turned on so that a first node is electrically coupled to a power supply voltage, and attains the “H” level. Further, a second switch is turned on to couple electrically the ground voltage to a second node. In a standby mode, the first and second control signals are at the “L” and “H” levels, respectively. In response to this, a third switch is turned on to couple electrically the first and second nodes together. Since the power supply voltage was electrically coupled to the first node according to the turn-on of the first switch in the active mode, the path of the control signal including the first node to the switch has accumulated charged charges.

Abstract: A semiconductor device according to example embodiments that may include an on-die termination (ODT) control circuit having a pipe line structure which changes in response to a frequency of a clock signal and a termination resistance generator for generating termination resistance in response to a termination resistance control signal.

Abstract: A circuit including control logic; and configurable impedance logic, operatively coupled to the control logic, comprising a configurable transistor structure operative to selectively change from a high impedance mode where the configurable transistor structure is configurable as a plurality of series connected diodes having their cathodes coupled together, and a low impedance mode where the configurable transistor structure is configurable to include a plurality of cascoded transistors. The circuit may further include at least one control signal line from the control logic to the configurable impedance logic, where the control signal line is operative to provide a control signal for configuring the configurable impedance logic.

Abstract: In one embodiment of the present invention, a technique is provided to control leakage of a cache sub-array. Other embodiments are disclosed herein. A sleep and shut-off circuit is connected between a virtual supply terminal and a first physical supply terminal to reduce leakage from the cache sub-array when the cache sub-array is disabled in a shut-off mode. The cache sub-array is connected between the virtual supply terminal and a second physical supply terminal. An active circuit is connected to the sleep and shut-off circuit in parallel to enable the cache sub-array in a normal mode and to disable the cache sub-array in the shut-off mode.

Abstract: Embodiments disclosed herein provide sleep mode solutions for retaining state information while reducing power in a logic block.

Abstract: A combined input and termination circuit comprises a fixed portion of impedance and a programmable portion of impedance. The fixed portion is able to be fixed in a driver mode and a termination mode. The programmable portion is able to be configured to have a desired impedance in a driver mode or a termination mode while maintaining minimum associated capacitance.

Abstract: In various embodiments of the invention, a power-harvesting termination circuit may be used to 1) match the impedance of a signal line being terminated, and 2) recover a portion of electrical power from a signal on the signal line and provide the recovered power as an electrical voltage to be used to power other circuits. The power may be harvested at either the receiving device or at the transmitting device.

Abstract: A semiconductor integrated circuit includes a CMOS controlled inverter consisting of series-connected PMOS and NMOS transistors. The source of the NMOS transistor is coupled to a ground line through an additional NMOS transistor for power gating of voltage VSS. The source of the PMOS transistor can be coupled to a power supply line through an additional PMOS transistor for power gating of voltage VDD. The inverter receives an input signal IN and its complementary version that has transitioned earlier than the input signal. In response to the input signal, the inverter produces an output signal. A NAND gate that receives the output signal and the complementary input signal controls the power gating NMOS transistor. A NOR gate that receives the output signal and the complementary input signal controls the power gating PMOS transistor.

Abstract: A method to reduce power consumption within a clock gated synchronous circuit, said synchronous circuit comprising at least two successive stages, wherein each stage if activated propagates a data signal cycle by cycle to a succeeding stage, comprising the steps of: deriving a local clock activation signal from an external clock activation signal, wherein said local clock activation signal changes its value every cycle the external clock activation signal indicates a propagation, propagating the data signal and the local clock activation signal synchronously cycle by cycle from a particular stage to a succeeding stage whenever a local clock activation signal at the particular stage by derivation from the clock activation signal or by propagation through the synchronous circuit changes its value between two successive cycles, in order to propagate the data signal and the local clock activating signal within the same clock domain through the clock gated synchronous circuit.

Abstract: An output circuit providing an adjustable output amplitude and common-mode voltage is described. The output circuit includes at least one driver circuit and a common-mode feedback circuit including a first replica circuit of the at least one driver circuit. The common-mode feedback circuit is coupled to receive a first bias and provide an output coupled to the at least one driver circuit. The output circuit may also include a current circuit having a configurable resistor and a second replica circuit of the at least one driver circuit. The current circuit may be coupled to receive a second bias and to provide an output coupled to the at least one driver circuit and the common-mode feedback circuit.

Abstract: A semiconductor integrated circuit includes an output driver, a replica driver, a replica resistor, and an impedance adjustment circuit. The output driver is configured to be capable of changing current driving capability. The replica driver is configured to be capable of changing current driving capability. The replica resistor is connected to an output of the replica driver. The impedance adjustment circuit is configured to adjust the current driving capability of the output driver and the replica driver, based on an output voltage of the replica driver. In addition, the output driver, the replica driver, the replica resistor, and the impedance adjustment circuit are mounted in an integrated circuit package.

Abstract: System and method for reducing power-on transient current magnitude on distributed header switches. A preferred embodiment comprises a distributed header switch coupling a circuit to a power supply, the distributed header switch comprising a linear sequence of combination switches, each combination switches containing a pre-charge switch and a header switch. A first-pass involves sequentially turning on each of the pre-charge switches, which enables a voltage level at the distributed header switch to approach that of a final voltage level and a second-pass involves sequentially turning on each of the header switches. Since the voltage level at the distributed header switches is close to the final voltage level, a resulting transient current is small in magnitude.

Abstract: A design method places power gates or switch cells using unoccupied locations of logic cell rows. Two types of such switch cells, filler switches and sealer switches, may be provided using the unoccupied locations. In one embodiment, virtual ground voltage references to the logic cells are routed to their associated switch cells. Because conventional standard cell design and placement techniques achieve only a placement density or utilization between 70-80% (i.e., unoccupied space constitutes between 20 to 30% of the available space in each row of logic cells), by placing the power gate cells in the unoccupied space, the method does not increase the silicon real estate requirement even though the power gate cells are introduced into the design. Optimization techniques may be applied to achieve proper sizing and distribution of power gate cells, so as to avoid a performance penalty due to the power gate cells.

Abstract: On-die-termination control circuit includes a clock generator configured to generate shift clocks in response to an on/off control signal; and a shift register configured to delay the on/off control signal in synchronization with the shift clocks to control on/off timing of an ODT operation.

Abstract: A storage circuit has an input for receiving and storing data, a first power terminal coupled to a first conductor for receiving a first power supply voltage, and a second power terminal coupled to a second conductor. A power gate device has a first terminal coupled to the second conductor, a control terminal for receiving a bias voltage in response to a control signal, and a second terminal coupled to a terminal for receiving a second power supply voltage. A shorting device selectively electrically short circuits the first terminal of the power gate device to the control terminal of the power gate device in response to the control signal, thereby converting the power gate device from a transistor into a diode-connected device. The shorting device is smaller in size than the power gate device.

Abstract: An input buffer has a high voltage leg in parallel with a low voltage leg. The low voltage leg pulls up the pad when the pad voltage is below the power supply voltage. The high voltage leg remains off when the pad voltage is below the power supply. The low voltage leg is turned off when the pad voltage is above the power supply voltage. The high voltage leg is on when the pad voltage is above power supply voltage. A low voltage bias circuit and a high voltage bias circuit protect the transistors in the low and voltage legs when the pad voltage is above the power supply voltage. As a result, the pull-up circuit is high voltage tolerant and does not sink the current from pad.

Abstract: Disclosed herein is a semiconductor integrated circuit including, a circuit section, a first voltage line, a second voltage line, a third voltage line, a switch section, and a control section.

Abstract: A semiconductor integrated circuit device has a combinational logic circuit including one or plural logic cells connected in series. At least one of the logic cells includes a standard cell which includes a MIS transistor, an input terminal to which an output signal from a previous stage is inputted as an input signal, and an output terminal. A first conductivity-type first MIS transistor which is provided between the output terminal of the standard cell and a first power supply voltage, the first MIS transistor including a control terminal to which a circuit control signal is inputted, and the first MIS transistor supplying the first power supply voltage to the output terminal of the standard cell based on the circuit control signal in order to bring the standard cell into an operation-stopped state. A second conductivity-type second MIS transistor cuts off a leakage current of the MIS transistor in the standard cell.

Abstract: A two-wire transmitter for receiving power supply from an external circuit through two transmission lines and also transmitting a current signal based on the measurement value of a sensor includes a current control section to which a voltage is supplied from an external circuit, for controlling the current value of the current signal based on an electric signal responsive to the measurement value of the sensor, if current consumption of the two-wire transmitter becomes smaller than the current value of the current signal, the current control section for charging and if the current consumption becomes larger than the current value of the current signal, the current control section for discharging; a computation control section for outputting the electric signal to the current control section and also outputting a setting signal based on predetermined computation processing information; a clock supply circuit for controlling the frequency of a clock signal based on the setting signal and supplying the clock sig

Abstract: A circuit incorporating a current starved ring oscillator is coupled to a power gate switch in an integrated circuit. The circuit incorporating the current starved ring oscillator amplifies a voltage difference between a virtual ground associated with the power gate switch and ground, and converts the difference to a frequency. Digital logic monitors the output of the ring oscillator using a counter and a reference clock. Control circuitry controls operation of the integrated circuit in dependence on the monitored conditions associated with the power gate switch. A method monitors a virtual ground voltage across a power gate switch in an integrated circuit; and controls operation of the integrated circuit in dependence on the monitored virtual ground voltage.

Abstract: A system-on-chip or other circuit has an on-chip noise-free ground which is added to divert ground noise from the sensitive nodes. An on-chip decoupling capacitor, tuned in resonance with the parasitic inductance of the interconnects, can be provided to add an additional low impedance ground path.

Abstract: The present invention provides a voltage divider circuit capable of reducing a number of external devices and lowering the cost and power consumption. The present invention includes a plurality of resistors connected in series, a plurality of buffers and at least one source driver IC. In addition, a first terminal of the first resistor is electrically connected to a DC voltage and the first terminal of each of the remaining resistors is electrically connected to the second terminal of the previous resistor. The second terminal of the last resistor is grounded. The buffers and the resistors are correspondingly electrically connected, wherein the first terminals of the resistors are electrically connected to their corresponding input terminals of buffers. Moreover, the output terminals of the buffers are electrically connected to source driver ICs, wherein the buffers are one of the built-in buffers in each source driver IC.

Abstract: Voltage regulator circuitry is provided. The voltage regulator circuitry is suitable for powering core logic on a programmable logic device. The voltage regulator circuitry receives an external power supply voltage and reduces the external power supply voltage to a core power supply voltage if needed. If the external power supply voltage is at the same level needed to power the core logic, the voltage regulator circuitry passes the power supply voltage to the core logic. The voltage regulator circuitry monitors the core power supply voltage using a feedback path. Overshoot and undershoot fluctuations are minimized. The external power supply voltage may be supplied to a first bus. The core power supply voltage may be distributed on a second bus. A ring of transistors may be used to convey power from the first bus to the second bus. Control circuitry may control the ring of transistors based on programmable setpoint voltages.

Abstract: A design method places power gates or switch cells using unoccupied locations of logic cell rows. Two types of such switch cells, filler switches and sealer switches, may be provided using the unoccupied locations. In one embodiment, virtual ground voltage references to the logic cells are routed to their associated switch cells. Because conventional standard cell design and placement techniques achieve only a placement density or utilization between 70-80% (i.e., unoccupied space constitutes between 20 to 30% of the available space in each row of logic cells), by placing the power gate cells in the unoccupied space, the method does not increase the silicon real estate requirement even though the power gate cells are introduced into the design. Optimization techniques may be applied to achieve proper sizing and distribution of power gate cells, so as to avoid a performance penalty due to the power gate cells.

Abstract: A storage circuit has an input for receiving and storing data, a first power terminal coupled to a first conductor for receiving a first power supply voltage, and a second power terminal coupled to a second conductor. A power gate device has a first terminal coupled to the second conductor, a control terminal for receiving a bias voltage in response to a control signal, and a second terminal coupled to a terminal for receiving a second power supply voltage. A shorting device selectively electrically short circuits the first terminal of the power gate device to the control terminal of the power gate device in response to the control signal, thereby converting the power gate device from a transistor into a diode-connected device. The shorting device is smaller in size than the power gate device.

Abstract: Apparatus and method aspects for power gating of an integrated circuit (IC) include providing at least one I/O power pad of an IC with a switch arrangement. The at least one I/O power pad is utilized to control a power signal transfer to at least a portion of the IC.

Abstract: A digital circuit with dynamic power and performance control via per-block selectable operating voltage level permits dynamic tailoring of operating power to processing demand and/or compensation for process variation. A set of processing blocks having a power supply selectable from two different power supply voltage levels is provided. The power level of the overall circuit is set by selecting the power supply voltage for each block to yield a combination of blocks that meets operating requirements. Alternatively, one circuit per pair from a set of pairs of redundant logic blocks supplied by the different power supply voltage levels can be selected to meet the operating requirements. The unselected blocks can be disabled by disabling foot devices or disabling transitions at the inputs to the unselected blocks. Performance measurement and feedback circuits can be included to tune the power consumption and performance level of the circuit to meet an expected level.

Abstract: Systems and methods for current management for digital logic devices are provided. In one embodiment, a method of current management for a digital logic circuit comprises drawing power to drive a digital logic integrated circuit; determining a priori information about an impending current need of the digital logic integrated circuit; and controlling a bypass current in parallel with the digital logic integrated circuit based on the a priori information, wherein the bypass current is controlled to reduce discontinuities in the current supplied by a power supply.

Abstract: A calibration circuit of an on-die termination device includes a code generating unit configured to receive a voltage of a calibration node connected to an external resistor and a reference voltage to generate pull-up calibration codes. The calibration circuit also includes a pull-up calibration resistor unit configured to pull up the calibration node in response to the pull-up calibration codes. The pull-up calibration resistor unit is calibrated such that its resistance becomes higher as a power supply voltage increases.

Abstract: An analog buffer used in a source driver is provided. The analog buffer havs an input end, an output end, a transistor, first and second capacitors, first, second, third, fourth and fifth switches. The source and the drain of the transistor is coupled to the output end and receives a first voltage respectively. The first end of the first and the second capacitors are coupled to the gate of the transistor. The second end of the first and the second capacitors are coupled to the first end of the first, second and fourth switches and the first end of the third and fifth switches respectively. The second end of the first switch receives a second voltage. The second end of the second and third switches are coupled to the input end. The second end of the fourth and fifth switches are coupled to the output end.

Abstract: Integrated circuit (IC) system architectures that allow for the reduction of on-chip or across-chip transient noise budgets by providing a means to avoid simultaneous high current demand events from at least two functional logic blocks, i.e., noise contributors, are disclosed. Embodiments of the IC systems architectures include at least one noise event arbiter and at least two noise contributor blocks. A method of scheduling on-clip noise events to avoid simultaneous active transient noise events may include, but is not limited to: the noise event arbiter receiving simultaneously multiple requests-to-operate from multiple noise contributers; the noise event arbiter determining when each noise contributer may execute operations based on a pre-established dI/dt budget; and the noise event arbiter notifying each noise contributer as to when permission is granted to execute its operations.

Abstract: A semiconductor device including an AND-NOR composite gate of which AND unit is supplied with input signals IN and VDD and NOR unit is supplied with an inverted signal EB of an enable signal E, and an AND-NOR composite gate of which AND unit is supplied with an input signal INB and an enable signal E and NOR unit is supplied with VSS. These gates are inserted into a path to which the input signals IN and INB are supplied. Thereby, a symmetric property of a complimentary signal can be retained. Further, outputs of the AND-NOR composite gates are fixed irrespective of a logical level of the enable signal E. Thus, a sub-threshold current also is inhibited.

Abstract: A first current source generating a current I0+I when a control signal is in ‘H’ level and a current I0 when it is in ‘L’ level, a current mirror circuit transferring a current generated in the first current source and composed of first and second MOS transistors, and a second current source connected to the second transistor and generating I0+I are provided. Further, a node branched from a connection node between the second transistor and the second current source is formed, and a logic unit including a flip-flop circuit formed of a differential amplifier is driven through the node. The logic unit is in an active state when the control signal is in ‘H’ level and it is in an inactive state when the signal is in ‘L’ level. When the logic unit is in an active state, it processes a data input signal to generate data output signal.

Abstract: A method for enhancing a CML driver circuit to allow efficient, and accurate measurement of the magnitude of the voltage domain noise present near a CML driver in an integrated circuit. The disclosed method for enhancing a CML driver circuit to enable quiet driver measurement includes providing a predetermined low impedance path from the power rail of said CML driver circuit via a first node to the output pins of the circuit and providing a predetermined low impedance path from the ground rail of said CML driver circuit via a second node to the output pins of the circuit. The method also includes disabling the current source causing the pull-up termination circuitry to become high impedance, and the logic driving said inputs of the CML circuit to exist in a low state and performing a low impedance measurement of the power rail noise, ground rail noise and the chip noise in the region of the CML driver.

Abstract: A semiconductor device includes main power supply wirings VDD and VSS, an pseudo power supply wiring VDT, inverters connected between the pseudo power supply wiring VDT and the main power supply wiring VSS, and inverters connected between the main power supply wiring VDD and the main power supply wiring VSS. Between the main power supply wiring VDD and the pseudo power supply wiring VDT, an N-channel MOS transistor and a P-channel MOS transistor that are rendered a conductive state at the time of active are connected in parallel. According to the present invention, the transistors different in conductivity type are used in parallel, and thus, it becomes possible to reduce power consumption at the time of standby while suppressing a decrease in switching speed from a standby state to an active state.

Abstract: An integrated circuit device includes a programmable logic block, a monitoring input, a condition-sensing circuit coupled to the monitoring input and configured to generate a condition-sensed signal at an output in response to sensing a condition at the monitoring input, a first digital input, a first digital output, and a gating circuit configured in the programmable logic block and coupled between the first digital input and the first digital output. The gating circuit has a gating input coupled to the condition-sensing circuit and generates an output. The output is related to an input state of the first digital input in the absence of the condition-sensed signal and assumes an override state in the presence of the condition-sensed signal.

Abstract: Transistors having large gate tunnel barriers are used as transistors to be on in a standby state, MIS transistors having thin gate insulating films are used as transistors to be off in the standby state, and main and sub-power supply lines and main and sub-ground lines forming a hierarchical power supply structure are isolated from each other in the standby state so that a gate tunnel current is reduced in the standby state in which a low power consumption is required. In general, a gate tunnel current reducing mechanism is provided for any circuitry operating in a standby state and an active state, and is activated in the standby state to reduce the gate tunnel current in the circuitry in the standby state, to reduce power consumption in the standby state.

Abstract: A first and a second charging circuit each having a diode and a capacitor are connected to a buffer. In the first charging circuit, an overshoot based on a reflected signal generated by an output signal is stored as an electric charge to the capacitor, and in the second charging circuit, an undershoot based on a reflected signal generated by an input signal is charged as an electric charge to the capacitor, whereby the energy of the overshoot and the like is recovered. These charges are collected in the charging circuit, stored in the capacitor, converted into a power supply voltage of an internal power supply by a stabilization circuit, and are supplied as an internal power supply. The reflected energy of the signal generated during signal transmission at the time of data transfer between semiconductor devices is stored, and the stored energy is used in driving the signals.

Abstract: Methods and circuitry for reducing ground bounce and VCC sag effects in integrated circuit (“IC”) devices is provided. In particular, a via-programmable design for I/O circuitry in IC devices is provided. The via-programmable I/O circuitry is used to disconnect I/O pin driver circuitry from and create a substantially direct connection between unused I/O pins and the ground and/or VCC signals of an IC device to reduce ground bounce and VCC sag, respectively.

Abstract: In one general aspect, a system may include a circuit board, a first integrated circuit attached to the circuit board, and a second integrated circuit attached to the circuit board being separate from the first integrated circuit and configured to operate in multiple power domains that include at least a core power domain and an I/O power domain and that is configured with a logic gate to receive and process external requests from the first integrated circuit and internal requests from the second integrated circuit for a common external resource.

Abstract: A power management circuit is provided for controlling power dissipation in at least one combinational logic circuit. The power management circuit includes a detector operative to receive at least a first input signal to the combinational logic circuit and to detect a transition of the first input signal between a first logic state and a second logic state. The detector generates a control signal indicative of whether or not a transition of the first input signal has occurred.

Abstract: A system and method for eliminating step response power supply perturbation during voltage island power-up/power-down on an integrated circuit is disclosed. An IC chip communicates with a primary power supply and includes at least one voltage island. A primary header on the voltage island of the chip communicates with the primary power supply via a primary header power path. A secondary header on the voltage island of the chip communicates with a secondary power supply via a secondary header power path. A control decoder communicating with the IC chip and the voltage island regulates the state of the primary and secondary headers.

Abstract: A description is given of an arrangement for compensation of ground offset in a data bus system comprising a plurality of communication devices (2, 10) which are each supplied with an operating voltage (U0) by a voltage source (4; 14), are connected to ground (G1); G2) and have a data bus connection (6; 12) via which they are connected to a data bus line (8). The special thing about the invention is that between operating voltage (U0) and ground (G2) at least one voltage dividing device (R3, R6) is connected whose output is coupled to the data bus connection (12) of at least one communication device (10) and whose voltage dividing ratio is selected such that an offset of the ground (G2) of the communication device (10), whose data bus connection (12) is coupled to the voltage dividing device (R3, R6), is in essence compensated compared to ground (G1) of another communication device (2).

Abstract: A semiconductor device includes a resistive element having a resistance characteristic not influenced by fluctuations in power supply voltage and a signal output circuit having a desired output impedance characteristic not influenced by fluctuations in power supply voltage. A constant current based on a reference voltage corresponding to a ground potential point is generated, and passed to a first resistive element whose one end is connected to a power supply voltage terminal. A voltage generated by the first resistive element is supplied to a first differential amplifier, whose output voltage is supplied to the gate of a first MOSFET whose source is connected to the power supply voltage terminal. A drain voltage to the first MOSFET is fed back to the first differential amplifier. A first current source is between the drain of the first MOSFET and the ground potential point. A second MOSFET is used as a resistive element.