Cypress Semiconductor Corporation

Satish C Saripella

Jeffery Scott Hunt

Ajay Srikrishna

Sudhaker Reddy Anumula

Andrew L Hawkins

George M Ansel

Jeffrey William Waldrip

Jeffrey Scott Hunt

Sanjay Sunder

Timothy M Lacey

Donald Y Yu

Derrick J Savage

William Randolph Hiltpold

An input buffer circuit has a pass gate circuit coupled to an input. A pseudo-differential amplifier is coupled to the pass gate circuit. A level shifter is coupled to the pseudo-differential amplifier.

Input buffer circuit

An apparatus comprising a pullup circuit, a pulldown circuit, and a control circuit. The pullup circuit may be configured to receive a first and second control signal. The pulldown circuit may be configured to receive a third and fourth control signal. The control circuit may be configured to generate the first, second, third and fourth control signals. The control circuit may comprise (i) a first and second control device coupled between the first and second control signals and a supply and (ii) a third and fourth control device coupled between the third and fourth control signals and the supply.

Circuit technique for improved current matching in charge pump PLLS

An apparatus comprising a first device and a second device. The first device may be connected to a first supply voltage. The second device may be connected (i) in series with the first device and (ii) to a second supply voltage. The first device is generally biased to provide enhanced noise suppression performance. The second device is generally configured to switch between the first and second supply voltages.

Low noise switching regulator

A voltage regulator includes a static regulator that provides a static regulated supply output as a reference input to a dynamic regulator to provide a regulated supply voltage. In one embodiment, multiple dynamic regulators are connected to the static regulated supply output of the static regulator. The one or more dynamic regulators dynamically detect when the regulated supply voltage is loaded below a predetermined reference level, and provide extra current in response to prevent the regulated supply voltage from drooping. Since the static regulator is capable of handling large average currents, the dynamic regulator circuit can be smaller than a typical dynamic regulator for an equivalent load. Furthermore, since the dynamic regulator provides transient current requirements, the size of the static regulator may be likewise smaller in size than a typical static regulator for an equivalent load.

Voltage regulator

An apparatus comprising a first circuit, a second circuit and a switch. The first circuit may be configured to receive a first supply voltage and may be coupled to a first ground. The second circuit may be configured to receive a second supply voltage and may be coupled to a second ground. The second circuit may be disabled in response to a control signal. The first and second supply voltages may be controlled by a reference voltage. The switch may be coupled between the first and second circuits and may be configured to connect the first and second circuits when the second circuit is disabled.

Method, circuit and/or architecture for reducing gate oxide stress in low-voltage regulated devices

A circuit and method comprising a memory, a first latch, a second latch and a control circuit. The memory may be configured to write information in response to (i) an input data signal and (ii) an address signal. The first latch may be configured to hold the address in response to a control signal. The second latch may be configured to hold the data input signal in response to the control signal. The control circuit may be configured to present the control signal in response to (i) an enable signal and (ii) a detect signal.

Method, architecture and circuit for writing to and reading from a

A circuit and method for generating an evaluation signal used to turn OFF one or more sense amplifiers. The sense amplifiers may be configured to present a first and second output in response to (i) an input signal and (ii) an enable signal. A detect circuit may be configured to present a detect signal in response to the first and second outputs. A control circuit may be configured to present the enable signal in response to (i) the detect signal and (ii) a wordline signal.

Self-timed sense amplifier evaluation scheme

A reference voltage generator may include an input for receiving a first voltage for input to a sense amp. The reference voltage generator may also include an output for outputting a second voltage for input to the sense amp. The second voltage is influenced by the first voltage. Alternatively, a reference voltage generator may include a first input for receiving a first voltage on a first bitline. The reference voltage generator may also include a first output for outputting a second voltage on a second bitline. The second voltage is influenced by the first voltage. Alternatively, a reference voltage generator may include a first input for receiving a first voltage on a first transmission busline. The voltage generator may also include a first output for outputting a second voltage on a second transmission busline. The second voltage is influenced by the first voltage.

Reference voltage generator for reading a ROM cell in an integrated

A circuit and method comprising a memory, a first latch, a second latch and a control circuit. The memory may be configured to write information in response to (i) an input data signal and (ii) an address signal. The first latch may be configured to hold the address in response to a control signal. The second latch may be configured to hold the data input signal in response to the control signal. The control circuit may be configured to present the control signal in response to (i) a detect signal and (ii) a transition of the address signal.

Method, architecture and circuit for writing to a memory

A circuit comprising a sense amplifier, an evaluation circuit, a control circuit and a register circuit. The sense amplifier circuit may be configured to present a first output and a second output in response to (i) an input signal and (ii) an enable signal. The evaluation circuit may be configured to present an evaluation signal in response to the first and second outputs. The control circuit may be configured to present (i) a first clock signal, a second clock signal and an enable signal in response to (i) the evaluation signal and (ii) a wordline signal. The register circuit may be configured to hold either the first or second output in response to the first and second clock signals. The register circuit may be implemented as a master-slave register that may respond to the first and second clock signals.

Method, architecture and circuit for reducing and/or eliminating small

The present invention concerns a circuit comprising a memory array having a plurality of wordlines and a plurality of bitlines, a reference circuit, a column select circuit, an enable control circuit, and one or more sense amplifiers. The reference circuit may be configured to present a reference voltage signal in response to (i) a dummy wordline and (ii) a virtual ground signal, where the dummy wordline may be synchronized with each of the plurality of wordlines. The column select circuit may be configured to present the virtual ground signal in response to a column select signal. The enable control circuit may be configured to present an enable signal in response to the dummy wordline. The sense amplifiers may be configured to generate an output in response to (i) the enable signal, (ii) the reference signal and (iii) the bitlines.

Wordline synchronized reference voltage generator

The present invention concerns a method and apparatus for providing a dual level wordline clamp for use in a memory array. During a write operation, the clamp is at a level that ensures that a proper write margin is maintained. During a read operation, the clamp produces a lower level that reduces the overall current consumption of the circuit. During a write operation, the clamp also reduces the overall current consumption of the circuit. The present invention does not require complex reference circuits and, as a result, presents a minimal impact on die size.

Dual level wordline clamp for reduced memory cell current

A memory device includes a random access memory (RAM) cell accessible through a RAM wordline and coupled between first and second bitlines; a read only memory (ROM) cell accessible through a ROM wordline and having an output coupled to the first bitline and an input configured to receive a first voltage signal; and a reference voltage generator having a first input coupled to the first bitline, a second input configured to receive the first voltage signal, and an output coupled to the second bitline. The memory device may further include a bitline load having an output coupled to the first bitline. A virtual ground driver configured to produce the first voltage signal may be coupled to the input of the read only memory cell. Further, column select pass gates configured to be under the control of a logic signal and having a first input coupled to the first bitline, a second input coupled to the second bitline, a first output and a second output may be provided. A sense amplifier having a first input coupled to the first output of the column select pass gates and a second input coupled to the second output of the column select pass gates may be included in the memory device. The memory device may be read by modulating a first voltage input to the sense amplifier using a second voltage input to the sense amplifier.

Read only/random access memory architecture and methods for operating

A level shifting circuit includes first and second load, gain and reference transistors. The first and second load transistors each have a source-drain path arranged between Vdd and Vss power supply voltages, and a gate coupled to the Vss power supply voltage. The first and second gain transistors each have a source-drain path arranged between the respective source-drain paths of the first and second load transistors and the Vss power supply voltage, and gates serving as respective differential input nodes. The first and second reference transistors each have a source-drain path arranged between the Vdd and Vss power supply voltages, and a gate coupled to respective first and second nodes serving as respective differential output nodes, the first node connecting the source-drain path of the first load transistor with the source-drain path of the first gain transistor, and the second node connecting the source-drain path of the second load transistor with the source-drain path of the second gain transistor. The level shifting circuit allows for stable and high speed level shifting operation for applications in a sense amplifier, provides a reasonable gain for driving a differential stage or a cascode amplifier stage, delivers a large output differential voltage swing at a supply voltage as low as 1.5 volts, detects small input differential voltages as low as 50 millivolts and is self-biased during changes in voltage, temperature and process conditions.

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Starkville, MS, United States of America

Satish C Saripella