Seiko Epson Corporation

Eitaro Otsuka

Masahiro Kanai

Koichi Mizugaki

Noboru Asauchi

Akihiro Fukuzawa

Masaya Uehara

A driver device that forms an oscillation loop with a vibrator and causes the vibrator to produce driving vibrations includes a current-voltage converter that converts a current that flows through the vibrator into a voltage, an output circuit that causes the vibrator to produce the driving vibrations based on a signal that is converted into a voltage with respect to a given voltage, and a high-pass filter that is provided in the oscillation loop between the current-voltage converter and the output circuit. The driver device causes the vibrator to produce the driving vibrations while changing a reference potential of the high-pass filter, and then causes the vibrator to produce the driving vibrations while fixing the reference potential.

Driver device, physical quantity measuring device, and electronic instrument

A driver device includes a gain control amplifier that causes a vibrator to produce driving vibrations by controlling an oscillation amplitude in an oscillation loop, a signal generation circuit that generates a signal having a given frequency, and a modulation circuit that modulates the frequency of the signal generated by the signal generation circuit to a resonance frequency of the vibrator. The driver device causes the vibrator to produce the driving vibrations using the signal modulated by the modulation circuit, and then causes the vibrator to produce the driving vibrations by controlling the oscillation amplitude in the oscillation loop formed by the vibrator and the gain control amplifier.

A detection circuit includes a detection terminal to which an alternating current signal from a physical quantity transducer is input, a detection current/voltage conversion amplifier circuit that converts the alternating current signal input through the detection terminal into a voltage signal, an evaluation terminal that supplies an evaluation voltage signal to the detection current/voltage conversion amplifier circuit, an input resistor that has a given resistance ratio with respect to a feedback resistor; and a switch circuit of the detection circuit provided in a signal path that connects the evaluation terminal and an input node of the detection current/voltage conversion amplifier circuit.

Detection circuit, physical quantity measurement circuit, physical quantity measurement device, and electronic instrument

An oscillation driver circuit includes a current-voltage converter which converts a current value of an oscillation signal in an oscillation loop into a voltage value, and a comparator which outputs a signal corresponding to the result of comparison between the output signal from the current-voltage converter and a given reference signal. The comparator has an output current limiting function. The oscillation driver circuit causes the vibrator to produce driving vibrations based on the output from the comparator.

A driver device that forms an oscillation loop with a vibrator and causes the vibrator to produce driving vibrations includes a current-voltage converter that is provided in the oscillation loop and converts a current that flows through the vibrator into a voltage, and a GCA as a comparator that is provided in the oscillation loop and outputs a signal corresponding to a comparison result between an output from the current-voltage converter and a given voltage. The GCA outputs a first high-level voltage or a low-level voltage during oscillation startup, and outputs a second high-level voltage or the low-level voltage in a steady oscillation state. The first high-level voltage is a voltage higher in potential than the second high-level voltage.

An oscillation driver circuit includes a gain control amplifier which causes a vibrator to produce driving vibrations by controlling an oscillation amplitude in an oscillation loop, and a comparator which generates a synchronous detection reference signal based on a signal in the oscillation loop. The oscillation driver circuit sets a gain in a first oscillation loop including the vibrator and the comparator to be larger than unity using an output from the comparator, and then causes the vibrator to produce the driving vibrations by controlling an oscillation amplitude in a second oscillation loop including the vibrator and the gain control amplifier in at least one of an oscillation startup state and a sleep mode.

Driving device, physical quantity measurement device, and electronic instrument

An oscillation driver circuit includes a gain control amplifier which causes a vibrator to produce driving vibrations by controlling an oscillation amplitude in an oscillation loop, and a comparator which generates a synchronous detection reference signal based on a signal in the oscillation loop. The comparator has an output current limiting function. The oscillation driver circuit causes the vibrator to produce vibrations using an output from the comparator in a state in which the gain in an oscillation loop formed by the vibrator and the comparator is set to be larger than unity, and then causes the vibrator to produce the driving vibrations by controlling an oscillation amplitude in an oscillation loop formed by the vibrator and the gain control amplifier.

An oscillation driver circuit that drives a physical quantity transducer includes a one-input/two-output comparator. The one-input/two-output comparator includes a shared differential section that compares a voltage signal input from a drive current/voltage conversion amplifier circuit with a given voltage, a first output section that receives a signal output from the differential section, variably adjusts a voltage amplitude of the received signal, and outputs the resulting signal, and a second output section that receives the signal output from the differential section, and outputs a synchronous detection reference signal of which the voltage amplitude is fixed.

Oscillation driver circuit, oscillation driver device, physical quantity measurement circuit, physical quantity measurement device, and electronic instrument

When the input write data is a value of a value greater than the existing data of the memory array, the semiconductor memory device enables writing of input write data to the memory array. In specific terms, the increment controllerreads the existing data from the memory array, and compares it with the write data latched to the 8-bit latch register. When the value of the write data is a value greater than the existing data, the increment controlleroutputs the write enable signal WENto the write/read controller, and executes writing of the write data latched to the 8-bit latch registerto the memory array

Semiconductor memory device

An oscillation driver device includes a gain control amplifier, an automatic gain control circuit, and a mode setting circuit. When the mode setting circuit has switched a mode from a normal operation mode to a low power consumption mode, the automatic gain control circuit is disabled, and the gain in an oscillation loop that drives the vibrator changes from a state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit to a state in which the gain in the oscillation loop is set to be larger than unity. When the mode setting circuit has switched the mode from the low power consumption mode to the normal operation mode, the automatic gain control circuit resumes operation, and the gain in the oscillation loop changes from the state in which the gain in the oscillation loop is set to be larger than unity to the state in which the gain in the oscillation loop is controlled to be unity by the automatic gain control circuit.

Oscillation driver device, physical quantity measuring device, and electronic instrument

When writing 16-bit write data to the memory arraywhich can store data of 8 bits per 1 row, the semiconductor memory devicefirst writes the upper 8 bits to the 1st write restricted row of the memory array. The increment controllerdetermines whether or not the value of the existing data written to the memory arrayand the write data used for writing latched to the 8-bit latch registermatch. When the existing data and the write data match, the increment controlleroutputs the write enable signal WENto the write/read controllerand executes the writing of the lower 8 bits of write data to the memory array

A semiconductor memory device comprises: a memory cell array having a standard memory cell array part in which dynamic memory cells are arranged in a matrix pattern, and a redundant memory cell array having a redundant memory cell set up to replace a defective memory cell in the standard memory cell array part; an access control part controlling external access operation and refresh access operation regarding the memory cell array; and a redundancy judgment circuit executing redundancy judgment to determine whether the memory cell which is a subject to the external access operation or the refresh access operation is the redundant memory cell or not, controlling so as to access the redundant memory cell, if the subjected memory cell is the redundant memory cell, and controlling so as to access the memory cell in the standard memory cell array, if the subjected memory cell is not the redundant memory cell. In case of executing the redundancy judgment for the refresh access operation by the redundancy judgment circuit and the refresh access operation according to generation of a refresh access request indicating the start of the refresh access operation, if the external access request indicating the start of the external access operation generates during the time from start of redundancy judgment for the refresh access operation until completion of the refresh access operation, the access control part makes the redundancy judgment circuit execute the redundancy judgment for the external access operation in parallel to the refresh access operation, and execute the external access operation after completion of the refresh access operation.

Semiconductor memory device capable of replacing defective memory cell with redundant memory cell, and electronic equipment

A semiconductor memory device includes: a plurality of memory cells arranged in a matrix; a memory cell array divided into a plurality of blocks; a plurality of read amplifiers, each of which is coupled correspondingly to each of the blocks; and a plurality of latch circuits, each group of which is coupled correspondingly to each of the read amplifiers and includes two or more latch circuits coupled to one another in parallel, wherein, in order to read a plurality of data consecutively from the memory cell array, the data are firstly read from one desired memory cell for each block; the read data are secondly inputted and latched, via the read amplifier corresponding to the same block, to one of the latch circuits included in a group of latch circuits corresponding to the same read amplifier; the data are thirdly read from another desired memory cell, which is different from the memory cell from which the data are formerly read, for each block; the read data are fourthly inputted and latched, via the read amplifier corresponding to the same block, to one of the latch circuits, which is different from the latch circuit to which the data are formerly latched, included in the group of latch circuits corresponding to the same read amplifier; and the latched data are lastly outputted in a desired order from each of the latch circuits having the latched data.

Semiconductor memory device having a plurality of latch circuits coupled to each read amplifier

The present invention provides a technique of causing a semiconductor device to output data if a read request not accompanied with an address change is issued. In a first situation in which a write request regarding a first data group is issued, a write operation of the first data group for a first group of memory cells among a set of memory cells selected by the current address is executed. When this occurs, a read operation of a second data group for a second group of memory cells among the set of memory cells is executed on a preliminary basis. The second group of memory cells is different from the first group of memory cells. In a second situation in which a read request for the second data group is issued while the current address is being maintained, the second data group that has been read preliminarily and held is externally output without executing a read operation for the second group of memory cells.

Growing community of inventors

Fujimi-machi, Japan

Eitaro Otsuka