56526 results about "Audio power amplifier" patented technology

An adapter allows the interconnection of a sensor originating from one manufacturer to be coupled with conventionally incompatible monitors originating from other manufacturers to form a properly functioning pulse oximetry system. The adapter matches a sensor driver in a monitor to the current requirements and light source configuration of a sensor. The adapter also matches a sensor's light detector signal level to the dynamic range requirements of a monitor preamplifier. Further, the adapter provides compatible sensor calibration, sensor type and security information to a monitor. The adapter may have a self-contained power source or it may derive power from the monitor, allowing both passive and active adapter components. The adapter is particular suited as an adapter cable, replacing a conventional patient cable or sensor cable as the interconnection between a sensor to a monitor in a pulse oximetry system.

A method of producing a diode drive current in an oximeter includes sensing at least a part of a current passing through the diode and converting the sensed current to a sensed voltage, inputting the sensed voltage to a feedback amplifier for stabilizing the current passing through the diode, and eliminating an offset voltage across inputs of the feedback amplifier. A pulse oximeter includes a diode for emitting light flashes, a feedback amplifier having inputs, a feedback capacitor, and an output, the feedback amplifier stabilizing a current passing through the diode, a nulling amplifier having inputs, a nulling capacitor, and an output, the nulling amplifier charging and discharging the feedback capacitor until the inputs of the feedback amplifier are at a same voltage. The operation may include synchronizing an elimination of input offset voltages of the feedback and nulling amplifiers with on or off state of diode current.

A patient module comprising an 8 channel EEG pre-amplifier whose signal acquisition and processing characteristics are optimized for use in the operating room and intensive care unit. This patient module comprises at least an optimized multistage input filter, an optimized input stage circuit topography, ultra-isolation, oversampling, a multiplexer inter-sample charge dump, and high performance low-frequency-enhanced shielding.

A non-volatile memory device capable of reading and writing a large number of memory cells with multiple read / write circuits in parallel has an architecture that reduces redundancy in the multiple read / write circuits to a minimum. The multiple read / write circuits are organized into a bank of similar stacks of components. Redundant circuits such as a processor for processing data among stacks each associated with multiple memory cells are factored out. The processor is implemented with an input logic, a latch and an output logic. The input logic can transform the data received from either the sense amplifier or the data latches. The output logic further processes the transformed data to send to either the sense amplifier or the data latches or to a controller. This provides an infrastructure with maximum versatility and a minimum of components for sophisticated processing of the data sensed and the data to be input or output.

Controls for an optical scanner, such as a single fiber scanning endoscope (SFSE) that includes a resonating optical fiber and a single photodetector to produce large field of view, high-resolution images. A nonlinear control scheme with feedback linearization is employed in one type of control to accurately produce a desired scan. Open loop and closed loops controllers are applied to the nonlinear optical scanner of the SFSE. A closed loop control (no model) uses either phase locked loop and PID controllers, or a dual-phase lock-in amplifier and two PIDs for each axis controlled. Other forms of the control that employ a model use a frequency space tracking control, an error space tracking control, feedback linearizing controls, an adaptive control, and a sliding mode control.

In a parallel operational processing device having an operational processing unit arranged between memory blocks each having a plurality of memory cells arranged in rows and columns, the respective columns of each memory block are alternately connected to the operational processing units on the opposite sides of the memory block. By selecting one word line in one memory block, data can be transferred to two operational processing units. The number of the word lines selected per one operational processing unit is reduced, and power consumption is reduced. The bit operation units and sense amplifiers / write drivers of the operational processing units have arrangement pitch conditions mitigated and are reduced in number, and an isolation region between the memory blocks is not required and the layout area is reduced. Thus, the parallel operational processing device with a layout area and the power consumption reduced, can achieve a fast operation.

A DRAM-like non-volatile memory array includes a cell array of non-volatile cell units with a DRAM-like cross-coupled latch-type sense amplifier. Each non-volatile cell unit has two non-volatile cell devices with respective bit lines and source lines running in parallel and laid out perpendicular to the word line associated with the non-volatile cell unit. The two non-volatile cell devices are programmed with erased and programmed threshold voltages as a pair for storing a single bit of binary data. The two bit lines of each non-volatile cell unit are coupled through a Y-decoder and a latch device to the two respective inputs of the latch-type sense amplifier which provides a large sensing margin for the cell array to operate properly even with a narrowed threshold voltage gap. Each non-volatile cell device may be a 2 T FLOTOX-based EEPROM cell, a 2 T flash cell, 11 T flash cell or a 1.5 T split-gate flash cell.

A sense amplifier of a memory array may be provided to amplify data presented from storage cells of the memory array. Additionally, a sense amplifier latch may be provided to store data received from the sense amplifier. The sense amplifier may be enabled for operation by a sense amplifier enable signal that is distinct from a clock signal. Moreover, the latch enable signal of the sense amplifier latch may be controlled by the sense amplifier enable signal, such that the sense amplifier latch opens in response to activation of the sense amplifier and closes in response to deactivation of the sense amplifier.

Various logic elements such as SR flip-flops, JK flip-flops, D-type flip-flops, master-slave flip-flops, parallel and serial shift registers, and the like are converted into non-volatile logic elements capable of retaining a current output logic state even though external power is removed or interrupted through the strategic addition of ferroelectric capacitors and supporting circuitry. In each case, the building blocks of a cross-coupled sense amplifier are identified within the logic element and the basic cell is modified and / or optimized for sensing performance.

A novel apparatus and method of improving the power efficiency of a digital transmitter for non-constant-amplitude modulation schemes. The power efficiency improvement mechanism of the invention leverages the high efficiency of a switched-mode power supply (SMPS) that supplies the high DC current to the transmitter's power amplifier, while compensating for its limitations using predistortion. The predistortion may be achieved using any suitable technique such as digital signal processing, hardware techniques, etc. A switched mode power supply (i.e. switching regulator) is used to provide a slow form (i.e. reduced bandwidth) of envelope tracking (based on a narrower bandwidth distorted version of the envelope waveform) such that the switching regulator can use a lower switching rate corresponding to the lower bandwidth, thereby obtaining high efficiency in the switching regulator. The resulting AM-AM and AM-PM distortions in the power amplifier are compensated through predistortion of the digital amplitude modulating signal which dictates the envelope at the PA input. Similarly, the phase modulation is also compensated prior to the PA, such that once it undergoes the distortion in the PA, the end result is sufficiently close to the desired phase.

A circuit includes an input stage, an output stage, and a delay stage. The input stage is operative to receive a clock signal and a first and second input signal. The output stage is operative to receive the clock signal. The output stage is also operative to generate a first and second output signal based on the clock signal and the first and second input signals. The delay stage is operatively coupled to the input and output stages. The delay stage includes a first and second branch. The second branch includes at least one more delay element than the first branch.

A data path for coupling data between a memory cell and an input / output (IO) line sense amplifier. An IO line coupling circuit is coupled to a pair of global data lines and a pair of local data lines to couple and decouple each of the global data lines to and from a voltage supply based on the voltage levels of the local data lines for the memory read operation. For the memory write operation, the IO line coupling circuit couples and decouples each of the global data lines to and from a respective one of the local data lines. The data path also includes a first precharge circuit coupled to the global data lines to couple the global data lines to ground to precharge the signal lines prior to a memory read or write operation, and can further include a test compression circuit coupled to the global data lines.

A content addressable memory (CAM) device and process for searching a CAM. The CAM device includes a plurality of CAM cells, match-lines (MLs), search lines, and ML sense amplifiers. The ML sense amplifiers are capable of self-calibration to their respective thresholds to reduce effects of random device variation between adjacent sense amplifiers.

Systems and methods for reducing the latency of data transfers between memory cells by enabling data to be transferred directly between sense amplifiers in the memory system. In one embodiment, a memory system uses a conventional DRAM memory structure having a pair of first-level sense amplifiers, a second-level sense amplifier and control logic for the sense amplifiers. Each of the sense amplifiers is configured to be selectively coupled to a data line. In a direct data transfer mode, the control logic generates control signals that cause the sense amplifiers to transfer data from a first one of the first-level sense amplifiers (a source sense amplifier) to the second-level sense amplifier, and from there to a second one of the first-level sense amplifiers (a destination sense amplifier.) The structure of these sense amplifiers is conventional, and the operation of the system is enabled by modified control logic.

A sense amplifier circuit senses and amplifies a signal read from memory cells arranged at intersections of word-lines and bit-lines. A write circuit reads first data held in a first memory cell of the memory cells, and writes second data corresponding to the first data in a second memory cell different from the first memory cell. A data latch circuit holds data read from the first memory cell. A logic operation circuit performs a logic operation using data read from the second memory cell and data held in the data latch circuit as input values and outputs third data as an operation value. A write-back circuit writes the third data back to the first memory cell.

A data path circuit of a semiconductor memory device includes: a bit line sense amplifier driven by a first power supply voltage; a local input / output line sense amplifier; a column selecting unit operatively connecting a pair of bit lines connected to the bit line sense amplifier and a pair of local input / output lines connected to the local input / output line sense amplifier in response to a column selection signal; and a local input / output line precharge unit precharging the pair of local input / output lines with a second power supply voltage different from the first power supply voltage during a period for which the column selection signal is in an inactive state.

A sense amplifier-based flip-flop includes a first latch, a second latch, a floating reduction unit, an input signal applying unit, a ground switch and a delay reduction unit. The first latch outputs a signal to a first output terminal pair, and outputs an evaluation signal pair corresponding to an input single pair to the first output terminal pair. The second latch latches the evaluation signal pair and outputs the evaluation signal pair to a second output terminal pair. The floating reduction unit is controlled by signals of the first output terminal pair and is operationally connected between current passing nodes of the first latch to prevent the first output terminal pair from floating. The input signal applying unit is disposed between the current passing nodes and a ground terminal, and receives the input signal pair. The ground switch is disposed between the input signal applying unit and the ground terminal, and is controlled by the clock signal. The delay reduction unit is disposed between the input signal applying unit and the ground switch, and reduces a signal delay from when the clock signal to when the evaluation signal pair is output from the second output terminal pair.

One or more sense amplifiers for sensing the conduction current of non-volatile memory is controlled by signals that are timed by a reference sense amplifier having similar characteristics and operating conditions. In one aspect, a sensing period is determined by when the reference sense amplifier sensing a reference current detects an expected state. In another aspect, an integration period for an amplified output is determined by when the reference sense amplifier outputs an expected state. When these determined timings are used to control the one or more sense amplifiers, environment and systemic variations are tracked.

A method for reducing source line bias is accomplished by read / write circuits with features and techniques for multi-pass sensing. When a page of memory cells are being sensed in parallel, each pass helps to identify and shut down the memory cells with conduction current higher than a given demarcation current value. In particular, the identified memory cells are shut down after all sensing in the current pass have been completed. In this way the shutting down operation does not disturb the sensing operation. Sensing in subsequent passes will be less affected by source line bias since the total amount of current flow is significantly reduced by eliminating contributions from the higher current cells. In another aspect of sensing improvement, a reference sense amplifier is employed to control multiple sense amplifiers to reduce their dependence on power supply and environmental variations.

A signal generator generates an electrical signal that is sent to an amplifier, which increases the power of the signal using power from a power source. The amplified signal is fed to a sender transducer to generate ultrasonic waves that can be focused and sent to a receiver. The receiver transducer converts the ultrasonic waves back into electrical energy and stores it in an energy storage device, such as a battery, or uses the electrical energy to power a device. In this way, a device can be remotely charged or powered without having to be tethered to an electrical outlet.

A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Modularity is ensured by the implementation of interchangeable amplifier components. System compactness is ensured by employing efficient fiber amplifiers, directly or indirectly pumped by diode lasers. Peak power handling capability of the fiber amplifiers is expanded by using optimized pulse shapes, as well as dispersively broadened pulses. After amplification, the dispersively stretched pulses can be re-compressed to nearly their bandwidth limit by the implementation of another set of dispersive delay lines. To ensure a wide tunability of the whole system, Raman-shifting of the compact sources of the ultrashort pulses in conjunction with frequency-conversion in nonlinear optical crystals can be implemented, or an Anti-Stokes fiber in conjunction with fiber amplifiers and Raman-shifters are used.