Abstract: Circuitry and methods for an improved gate driver circuit for power converters. The improved gate driver circuit substantially reduces propagation delay and transition losses in the floating-gate side of the gate driver circuit. One embodiment includes an inverter having an input configured to receive a state transition signal and an output configured to be coupled to a control input of a switching device. The inverter includes a first NFET having a control gate configured to be coupled to the state transition signal, a second NFET having a control gate coupled to the output of a reference circuit, and a PFET having a control gate configured to be coupled to the state transition signal, wherein the output of the inverter is a node between the conduction channels of the first NFET and the second NFET and the conduction channels of the first NFET, second NFET, and PFET are coupled in series.

Abstract: An embodiment level converter circuit is configured to receive, as a current supply, a current proportional to temperature.

Abstract: A line driver circuit include a multitude of PMOS and NMOS transistors. A first PMOS transistor receives an output voltage of a first level converter. A second PMOS transistor receives a first reference voltage. A third and fourth PMOS transistors receive an output voltage of a second voltage level converter. The source terminal of the first PMOS transistor receives the supply voltage. The drain terminal of the fourth PMOS transistor is coupled to an output terminal of the line driver circuit. A first NMOS transistor receives an input signal. A second NMOS transistor receives a second reference voltage. A third and fourth NMOS transistors receive an output voltage of a third level converter. The first NMOS transistor receives a ground potential. The drain terminal of the fourth NMOS transistor is coupled to the output terminal of the line driver. The first, second and third voltage converters receive the input signal.

Abstract: A gate driver drives a gate of a semiconductor switching element. The gate driver includes a command signal output circuit, a pre-drive circuit and a drive circuit. The command signal output circuit outputs a current command signal that indicates a command value of a gate current as a current flowing through the gate of the semiconductor switching element. The pre-drive circuit receives the current command signal and generate a drive signal corresponding to the current command signal to output the drive signal. The drive circuit drives the gate of the semiconductor switching element based on the drive signal. The command signal output circuit switches the command value indicated by the current command signal while controlling a transient voltage at a desired target value. The drive circuit includes output circuits connected in parallel. Each of output circuits has at least one cascode circuit in which two MOSFETs are cascode-connected.

Abstract: A level shifter, configured to shift an input voltage swing from a first voltage range to a second voltage range, comprising a first stage and a switching stage, with circuitry configured in isolation wells. The first stage includes a first stage input receiving an input signal that swings between a first voltage value and a second voltage, a buffer configured to shift the input signal to vary between a third value and a fourth value, and a first stage output configured to present a first stage output signal. The switching stage comprises switching stage inputs, configured to receive the first stage output signal, switch drivers, and switching devices configured to, responsive to the driver output, generate a switching stage output signal that is a shifted version of the input signal. The switching stage output signal ranges between a fifth voltage value and a sixth voltage value.

Abstract: Techniques are described herein to enhance capability of floating level translators. For example, increased headroom is accomplished by adaptively bypassing the protection elements of the voltage level translator. In an example, a floating level translator can translate an input signal from a low-voltage domain to a high-voltage domain. A bypass circuit is coupled across the protection elements. The bypass circuit selectively engages during low-voltage operation (e.g., thereby providing a lower loss path relative to loss caused by the high-voltage protection elements and thus increasing the headroom swing), and disengages responsive to the high-voltage reference rail of the high-voltage domain exceeding a threshold or otherwise being high enough (e.g., greater than the potential of the low-voltage domain power rail). The bypass circuit can be implemented in a relatively low-complexity manner (e.g., back-to-back high-voltage FETs) without additional signals to control low-voltage capability.

Abstract: This application relates to methods and apparatus for driving a transducer connected between two output nodes in a bridge-tied-load configuration. A driver receives first and second supply voltages and has charge pumps that generate respective first and second boosted voltages. The driver is operable in a first driver mode in which each output node is modulated between the first and second supply voltage; a second driver mode in which one output nodes is modulated between the first and second supply voltages and the other output node is modulated between either the first boosted voltage and the first supply voltage or between the second supply voltage and the second boosted voltage; and a third driver mode in which one of the output nodes is modulated between the first supply voltage and the first boosted voltage and the other output node is modulated between the second supply voltage and the second boosted voltage.

Abstract: An input/output (I/O) buffer is implemented without an auxiliary power supply (VCCAUX). The input/output (I/O) buffer includes a connection to a VCCO power supply, a connection to a VCCINT power supply, a connection to a reference voltage, and a VCCO detection circuit coupled to a bias generation circuit. Further, the I/O buffer includes a transmitter circuit coupled to the bias generation circuit, and a receiver circuit coupled to an I/O pad.

Abstract: An interface circuit includes: a plurality of signal transmitter circuits each receiving an input signal and outputting an output signal responsive to a first power supply voltage based on the input signal; an operation control circuit controlling operation/suspension of the signal transmitter circuits; and an amplitude control circuit exerting control so that the first power supply voltage be greater with increase in the number of operating circuits among the signal transmitter circuits and thereby the amplitude of the output signals of the signal transmitter circuits become greater.

Abstract: A semiconductor device includes an input, a level shifter, an output, and a switch module. The input is configured to receive an input signal in a first voltage domain. The level shifter is connected to the input and is configured to shift the input signal from the first voltage domain to a second voltage domain. The switch module is configured to connect one of the input and the level shifter to the output. A method of mitigating a delay between input and output signals of the semiconductor device is also disclosed.

Abstract: Provided is a voltage level shifter that operates in sub-threshold voltages. The level shifter includes a level shifting stage. The level shifting stage receives a first signal from a first voltage domain and outputs a second signal to a second voltage domain. The level shifter includes a first auxiliary stage. In response to the first signal having a first voltage level corresponding to a first logical state and a first node of the level shifting stage having a supply voltage level, the first auxiliary stage sources current to a second node of the level shifting stage. Sourcing the current to the second node accelerates a transition of the first node to a reference voltage. The level shifting stage outputs a second signal to a second voltage domain.

Abstract: Described is apparatus comprising a first circuitry, a second circuitry, and a third circuitry. The first circuitry may have an output coupled to a shared-read-data signal path, and the first circuitry either driving its output to a value based on a sensed memory bit, or not driving its output. The second circuitry may have a first clocked inverter and a second clocked inverter cross-coupled with the first clocked inverter, an input of the first clocked inverter being coupled to the shared-read-data signal path, and an output of the first clocked inverter being coupled to an inverse-data signal path. The third circuitry may have an inverter with an input coupled to the inverse-data signal path and an output coupled to a data signal path.

Abstract: A device including an inverter circuit, a hysteresis control circuit, and a high-side input level shifter. The inverter circuit having an output and including at least two series connected PMOS transistors connected, at the output, in series to at least two series connected NMOS transistors. The hysteresis control circuit coupled to the output to provide feedback to the at least two series connected PMOS transistors and to the at least two series connected NMOS transistors. The high-side input level shifter connected to gates of the at least two PMOS transistors and configured to shift a low level of an input signal to a higher level and provide the higher level to one or more of the gates of the at least two PMOS transistors.

Abstract: An unnecessary circuit operation in a clock enabler circuit accompanying toggling of a clock signal is suppressed. A state holding unit performs a holding operation of a state as to whether or not to output an output clock signal according to an internal clock signal. A clock signal output unit controls output of the output clock signal according to the state held in the state holding unit. A control unit supplies, to the state holding unit, the internal clock signal and a value of the state that are necessary for the holding operation in the state holding unit on a basis of a clock signal and a clock enable signal from an outside.

Abstract: A device including an inverter circuit, a hysteresis control circuit, and a high-side input level shifter. The inverter circuit having an output and including at least two series connected PMOS transistors connected, at the output, in series to at least two series connected NMOS transistors. The hysteresis control circuit coupled to the output to provide feedback to the at least two series connected PMOS transistors and to the at least two series connected NMOS transistors. The high-side input level shifter connected to gates of the at least two PMOS transistors and configured to shift a low level of an input signal to a higher level and provide the higher level to one or more of the gates of the at least two PMOS transistors.

Abstract: Methods and systems are provided for performing voltage level shifting using thin-oxide devices. The methods and systems convert an input signal associated with a first voltage domain to output signals associated with the first and second voltage domains. A first set of thin-oxide devices generate a first output signal at the high-level voltage signal when the input signal comprises a high logic level and generate the first output signal at a ground level voltage signal when the input signal comprises a low logic level. A second set of thin-oxide devices generate a second output signal at a power supply voltage level of the second voltage domain when the input signal comprises the high logic level and generate the second output signal at the second bias voltage when the input signal comprises the low logic level.

Abstract: A level-shifter is provided with a first transistor and a second transistor. The first transistor functions to discharge an internal node responsive to an assertion of an inverted input signal to a first power supply voltage. A second transistor functions to discharge an inverted level-shifter output signal responsive to an assertion of an input signal to the first power supply voltage. An inverter inverts the inverted level-shifter output signal to form a level-shifter output signal that is asserted to a second power supply voltage responsive to the assertion of the input signal.

Abstract: A digital isolator. The digital isolator a logic module for receiving an input signal D, and providing command signals to first and second sawtooth modulators. The first sawtooth modulator can provide a first sawtooth signal at a node A1 having a fast rising edge triggered by a rising edge of a control signal, followed by a slow falling edge, when D equals 1 and having a fast falling edge triggered by a rising edge of a control signal, followed by a slow rising edge, when D equals 0. A second sawtooth modulator provides a second sawtooth signal at node A2, inverted with respect to first sawtooth signal. Isolation capacitors connected to nodes A1 and A2 can be used as isolation barrier and as part of high-pass filters together with dipoles Z1 and Z2.

Abstract: A level shift circuit converts input signals in a first voltage domain into output signals in a second voltage domain. The level shift circuit includes a first voltage domain circuit, a middle voltage domain circuit, and a second voltage domain circuit. The middle voltage domain circuit convert the signals in the first voltage domain received by the first voltage domain circuit into signals in a middle voltage domain. The second voltage domain circuit converts the signals in the middle voltage domain into signals in the second voltage domain and outputs the converted signals. The signals in the middle voltage domain are partly different from the signals in the first voltage domain and the second voltage domain. Each signal in the first voltage domain is different from the signals in the second voltage domain. A display apparatus is also disclosed.

Abstract: Provided are a reset signal transmission circuit, a chip and an electronic device. The reset signal transmission circuit comprises a level shifting circuit and a first switching circuit, wherein the level shifting circuit is configured to transmit a reset signal from a first voltage domain to a second voltage domain, and the power supply voltage of the first voltage domain is lower than the power supply voltage of the second voltage domain. The first terminal of the first switching circuit is connected to the power supply signal input terminal of the level shifting circuit, and the second terminal of the first switching circuit is connected to the reset signal output terminal of the level shifting circuit. The first switching circuit is configured to control the disconnection of a quiescent current path in the level shifting circuit.

Abstract: A semiconductor device includes an input, a level shifter, an output, and a switch module. The input is configured to receive an input signal in a first voltage domain. The level shifter is connected to the input and is configured to shift the input signal from the first voltage domain to a second voltage domain. The switch module is configured to connect one of the input and the level shifter to the output. A method of mitigating a delay between input and output signals of the semiconductor device is also disclosed.

Abstract: A circuit includes an input circuit, a level shifter circuit, an output circuit, and a first and a second feedback circuit. The input circuit is coupled to a first voltage supply, and configured to receive a first input signal, and to generate at least a second input signal. The level shifter circuit is coupled to a second voltage supply, and configured to generate at least a first and second signal responsive to at least the enable signal or the first input signal. The output circuit is coupled to at least the level shifter circuit and the second voltage supply, and configured to generate at least an output signal, a first and second feedback signal responsive to the first signal. The first and second feedback circuit are configured to receive the enable signal, and the inverted enable signal, and the corresponding first and second feedback signal.

Abstract: Various embodiments of the present application are directed towards a level shifter with temperature compensation. In some embodiments, the level shifter comprises a transistor, a first resistor, and a second resistor. The first resistor is electrically coupled from a first source/drain of the transistor to a supply node, and the second resistor is electrically coupled from a second source/drain of the transistor to a reference node. Further, the first and second resistors have substantially the same temperature coefficients and comprise group III-V semiconductor material. By having both the first and second resistors, the output voltage of the level shifter is defined by the resistance ratio of the resistors. Further, since the first and second resistors have the same temperature coefficients, temperature induced changes in resistance is largely cancelled out in the ratio and the output voltage is less susceptible to temperature induced change than the first and second resistors individually.

Abstract: A semiconductor device includes an input, a level shifter, an output, and a switch module. The input is configured to receive an input signal in a first voltage domain. The level shifter is connected to the input and is configured to shift the input signal from the first voltage domain to a second voltage domain. The switch module is configured to connect one of the input and the level shifter to the output. A method of mitigating a delay between input and output signals of the semiconductor device is also disclosed.

Abstract: The present disclosure relates to a structure including a level shifter circuit which receives an input signal and at least one voltage reference signal and outputs at least one level shifted output signal, a pre-driver circuit which receives the at least one level shifted output signal and outputs at least one pre-driver output signal, the pre-driver circuit including at least one delay circuit, and a main driver circuit which receives the at least one pre-driver output signal and outputs a main driver output signal.

Abstract: A high voltage is generated from a low supply voltage by a charge pump driven with a pulse generator. A comparator compares the low supply voltage to a predetermined proportion of the high voltage. A low power voltage divider creates the predetermined portion of the high voltage. The comparator output drives the pulse generator, and the pulse generator output resets the comparator. A high voltage to low voltage mode may also be employed using the same arrangement.

Abstract: An apparatus comprises a plurality of analog front ends (AFEs) adapted to be coupled to a plurality of battery cells and configured to decrease voltages received from the plurality of battery cells to produce a plurality of AFE voltages. The apparatus further comprises at least one analog-to-digital converter (ADC) coupled to the plurality of AFEs and configured to convert the plurality of AFE voltages to a plurality of corresponding digital signals. The apparatus also comprises a plurality of digital channel registers coupled to the at least one ADC and configured to store the plurality of digital signals, and a processor coupled to the at least one ADC and configured to adjust, in a round-robin calculation scheme, the plurality of digital signals based on a plurality of common mode voltage values and a plurality of common mode to differential gain values associated with the plurality of AFEs.

Abstract: A touch panel display driver includes a source driver circuit, a touch detection circuit, a selector circuit, a register a plurality of source terminals, a plurality of touch detection terminals, and a plurality of selection terminals. The selector circuit electrically connects the source driver circuit to each of the source terminals, electrically connects the touch detection circuit to each of the touch detection terminals, and electrically connects each of the selection terminals to the source driver circuit or the touch detection circuit.

Abstract: Embodiments of level shifters are disclosed. In an embodiment, a level shifter includes a transistor connected between an input terminal of the level shifter and an output terminal of the level shifter, a first resistor connected between a first terminal of the transistor and one of the input terminal of the level shifter and the output terminal of the level shifter, a capacitor connected between the input terminal of the level shifter and the output terminal of the level shifter, a current source connected between the output terminal of the level shifter and a fixed voltage, and a resistor divider connected between the first resistor and the output terminal of the level shifter.

Abstract: A baseline wander and offset correction system having inputs configured to receive input signals to be transmitted. Also part of the system is a driver circuit configured to receive and amplify the input signals. The driver circuit is configured with one or more transistors having an optional back bias terminal. A replica circuit receives the input signals and responsive thereto, generates back bias signals which are provided to the back bias terminal of the one or more transistors to change the back bias in response to the input signals having consecutive one values or consecutive zero values. This reduces the size of the one or more AC coupling capacitors located between the driver circuit and a channel. An embodiment may store back bias values in a memory. The back bias values are processed by DAC to generate the back bias signals for offset correction.

Abstract: A gate driving circuit that can be stably driven by improving output characteristics of a last output buffer unit, and a display device comprising the gate driving circuit, are discussed. The gate driving circuit can include a plurality of subordinately connected stages, where an Nth (N being a natural number) stage includes a node controller configured to control voltages of a first node and a second node according to a set signal and a reset signal. The Nth stage can further include a plurality of scan pulse output units configured to receive a plurality of scan clocks, and output each of the scan clocks as a scan pulse according to voltages of the first node and the second node.

Abstract: The amplitude voltage of a signal input to a level shifter can be increased and then output by the level shifter circuit. Specifically, the amplitude voltage of the signal input to the level shifter can be increased to be output. This decreases the amplitude voltage of a circuit (a shift register circuit, a decoder circuit, or the like) which outputs the signal input to the level shifter. Consequently, power consumption of the circuit can be reduced. Alternatively, a voltage applied to a transistor included in the circuit can be reduced. This can suppress degradation of the transistor or damage to the transistor.

Abstract: Various devices, such as storage devices or systems are configured to transmit data between various components over one or more interfaces. The operation of these interfaces is based on the mechanical limits of the components doing the communication, often latches. Latches often require a setup and hold time limit on the signal being transmitted to be held a desired value. Because the physical effects of the environment, such as voltage being provided, temperature of the component, for example, can affect the operation of the latch, there is often a large margin used to operate them. These large margins avoid errors but decrease overall speed of the interface. By utilizing a test latch within an interface bus group with a drop in operating voltage, changes in output detected can be indicative of upcoming errors. Once detected, the error can be remedied by increasing voltage, lowering operating speeds, or cooling the components.

Abstract: A level shifter includes a buffer circuit, a first shift circuit, and a second shift circuit. The buffer circuit provides a first signal and a first inverted signal to the first shift circuit, such that the first shift circuit provides a second signal and a second inverted signal to the second shift circuit. The second shift circuit generates a plurality of output signals according to the second signal and the second inverted signal. The first shift circuit includes a plurality of first stacking transistors and a first voltage divider circuit. The first voltage divider circuit is electrically coupled between a first system high voltage terminal and a system low voltage terminal. The first voltage divider circuit is configured to provide a first inner bias to gate terminals of the first stacking transistors.

Abstract: A semiconductor device according to an embodiment includes: a logic control circuit to which a signal is input; a timing information storage circuit configured to store timing information related to a start timing of correction processing that corrects a duty cycle of the signal; and a sequencer configured to start execution of the correction processing based on the timing information when a command related to the execution of the correction processing is received.

Abstract: This disclosure relates to multi-phase oscillators for electronic systems. An example system includes multiple level translator circuits and a ring oscillator circuit that includes multiple outputs. Each level translator circuit includes a first input transistor, a second input transistor, and an output. The ring oscillator circuit includes multiple outputs, and each output of the ring oscillator has a different phase. An output of the ring oscillator is coupled to only one input transistor of a level translator circuit, and the other input transistor of the level translator circuit is coupled to an output of another level translator circuit.

Abstract: According to one embodiment, a semiconductor integrated circuit includes a first circuit that includes a level shift transistor, a transmission line through which the signal output from the first circuit propagates, a second circuit that is connected the transmission line to receive the signal propagating through the transmission line, and a third circuit that is connected to the transmission line. The first circuit is connected to a power supply line to which a first voltage is supplied, and outputs, to the transmission line, a signal having an amplitude lower than the first voltage by a threshold voltage of the level shift transistor. The third circuit allows a current to flow from the transmission line when a voltage of the transmission line exceeds a set voltage.

Abstract: An output driving circuit includes: a plurality of bias voltage generating circuits configured to generate a plurality of bias voltages; a switching control circuit; and an output voltage generating circuit. The switching control circuit is configured to selectively connect one bias voltage generating circuit of the plurality of bias voltage generating circuits to the output voltage generating circuit based on an output voltage. The output voltage generating circuit is configured to transmit and receive a parasitic current generated due to transition of the output voltage to and from the one bias voltage generating circuit selectively connected to the output voltage generating circuit through the switching control circuit.

Abstract: An aspect of the disclosure relates to an apparatus including a first field effect transistor (FET) including a first gate configured to receive a first input signal that varies in accordance with a first voltage domain; and a first inverter including a first input configured to receive a second input signal that varies in accordance with a second voltage domain, and a first output configured to generate a first output signal that varies in accordance with the second voltage domain, wherein the first output signal is based on the first and second input signals, and wherein the first FET and the first inverter are coupled in series between first and second voltage rails. Per another aspect, the apparatus includes additional circuitry to allow the apparatus to process signals in accordance with a third voltage domain.

Abstract: The present disclosure relates to a high-side transistor drive circuit, a switching circuit and a controller of a DC/DC converter. A pulse generator generates a first pulse that becomes high level for a certain period of time in response to a first edge of an input signal and a second pulse that becomes high level for a certain period of time in response to a second edge of the input signal. An open drain circuit has a first output node that becomes low level in response to the first pulse and a second output node that becomes low level in response to the second pulse. A first current mirror circuit folds back a first current flowing through the first output node of the open drain circuit. A second current mirror circuit folds back a second current flowing through the second output node of the open drain circuit.

Abstract: A level shifter circuit is disclosed. The level shifter includes an input circuit configured to receive an input signal generated using a first power supply voltage level and generate, using the first power supply voltage level, a first control signal and a second control signal using the input signal. The level shifter further includes a shifter circuit configured to generate a first shifted signal and a second shifted signal using the first control signal, the second control signal, and second power supply voltage level different than the first power supply voltage level, and a selection circuit configured to select, using a value of a previous output signal and the second power supply voltage level, one of the first shifted signal or the second shifted signal to generate a current output signal.

Abstract: An integrated circuit includes an input pad and a Schmitt trigger coupled to the input pad. The Schmitt trigger includes a first inverter and a second inverter. The Schmitt trigger includes a pull-up transistor coupled to an input of the second inverter and configure to supply a high reference voltage to the input of the second inverter.

Abstract: Improved voltage level shifters are disclosed capable of achieving substantially higher data transfer speeds with reduced static current than existing cross-coupled voltage level shifters. The voltage level shifters disclosed herein include first stage that translates input voltage signals received from a core circuitry in a first voltage domain to intermediate output voltage signals an intermediate voltage domain, and second stage circuitry that translates the intermediate output voltage signals received from the first stage circuitry in the intermediate voltage domain to output voltage signals in a second voltage domain. The disclosed voltage level shifters are scalable to support various logic voltage levels in the second voltage domain.

Abstract: Provided is a level shifter circuit that changes a voltage of a high-frequency input signal to output. Provided is a level shifter circuit provided with a first input terminal and a second input terminal to each of which an input signal having a level between a first potential level and a first reference potential level is input, a first output terminal and a second output terminal from each of which an output signal having a level between a second potential level higher than the first potential level and a second reference potential level is output, a second potential supply node that supplies a voltage at the second potential level, a reference potential supply node that supplies a voltage at the second reference potential level, first and second impedance elements, first to fourth transistors, and first and second nodes, in which each of the first impedance element and the second impedance element includes at least three terminals.

Abstract: The present technology may include a first detection unit configured to generate an output signal by detecting a level of an input terminal in response to a transition of a control clock signal during a normal read operation, and a second detection unit configured to generate the output signal by detecting the level of the input terminal regardless of the transition of the control clock signal during a state information read operation.

Abstract: An input/output circuit including: a pull-up driving circuit including at least one internal node coupled to a pad, the pull-up driving circuit configured to pull up a voltage of the pad to a Tx power supply voltage; and a pull-down driving circuit configured to pull down the voltage of the pad to a ground voltage. The pull-up driving circuit is configured to set a voltage level of the at least one internal node to a voltage level of a power supply voltage on the basis of a fixed voltage, when a voltage difference between the Tx power supply voltage and the voltage of the pad is greater than the voltage level of the power supply voltage.

Abstract: A level shifter and a chip with the level shifter are shown. Between the input pair and the cross-coupled output pair, there are a first protection circuit and a second protection circuit. An overdrive voltage, which is double the nominal voltage of the level shifter plus a delta voltage, is applied to the level shifter. The first protection circuit has a first voltage-drop circuit that compensates for the delta voltage. The second protection circuit has a second voltage-drop circuit that compensates for the delta voltage.

Abstract: A memory interface may include a transmitter that generates multi-level signals. The transmitter may employ channel equalization to improve the quality and robustness of the multi-level signals. The channel equalization may be controlled independently from the drive strength of the multi-level signals. For example, a first control signal may control the de-emphasis or pre-emphasis applied to a multi-level signal and a second control signal may control the drive strength of the multi-level signal. The first control signal may control a channel equalization driver circuit and the second control signal may control a driver circuit.

Abstract: Methods, systems, and apparatus described herein make a multi-level PAM signal (PAM-N signal) at a transmitter using CMOS-based components. By forming the PAM-N signal at the transmitter, receivers do not have to recombine and/or realign multiple signals and only employs a single transmission line channel (or two transmission line channels in differential implementations) to convey the data stream to the receiver from the transmitter.

Abstract: A memory device and a word line driver thereof are provided. The word line driver includes a first word line signal generator, a second word line signal generator, a first voltage generator, and a second voltage generator. The first word line signal generator selects one of a first voltage and a second voltage to generate a first word line signal according a control signal. The second word line signal generator selects one of a third voltage and a fourth voltage to generate a second word line signal according the control signal. The first voltage generator provides the second voltage, and the second voltage generator provides the fourth voltage, where the first voltage generator is independent to the second voltage generator.