Sonic Innovations, Inc.

Sonix Technologies, Inc.

Robert Sherman Green

Gerald A Wilson

Keith L Davis

Benjamin Edward Nise

A regulated voltage down pump circuit comprises a reference generator circuit receiving a voltage. P channel and N channel device voltage thresholds are measured and compared. A first reference voltage is generated using the largest voltage threshold. A second reference voltage is generated an amount (which may be programmable) above the first reference voltage. The second reference voltage is compared with an output voltage of a pump circuit. When the output voltage is less than the second reference voltage, a clock signal is sent to the pump circuit that generates and pumps up the output voltage to the reference voltage. The pumped voltage at the second reference is then used for logic circuits at reduced power and nearly constant gate delay over voltage, temperature and process variations.

Voltage down pump and method of operation

A simplified algorithm for digital signal interpolation and a novel architecture to implement the algorithm in an integrated circuit (&ldquo;IC&rdquo;) with significant space constraints are presented. According to embodiments of the present invention, the interpolator is divided into two parts. The first part of the interpolator increases the sample rate by a factor of two and smoothes the signal using a half-band Infinite Impulse Response (&ldquo;IIR&rdquo;) filter. The second part of the interpolator increases the sample rate of the signal by a factor of thirty-two using a zero-order-hold (&ldquo;ZOH&rdquo;) circuit. In one embodiment, the half-band IIR filter is implemented using an all-pass lattice structure to minimize quantization effects. The lattice coefficients are chosen such that the structure can achieve all filter design requirements, yet is capable of being implemented with a small number of shifters and adders, and no multipliers.

Multiplierless interpolator for a delta-sigma digital to analog converter

A system for detecting a low battery power condition and providing an audible warning of such a condition to a user of an electronic device such as a hearing aid is disclosed. In one embodiment, the battery output voltage is monitored and compared to a first threshold voltage at specified sampling intervals. When a battery output voltage measurement below the first threshold voltage is detected, this measurement is verified by a rule specifying that a low battery condition is not deemed to exist unless a predetermined percentage of voltage measurements within a predetermined time interval indicate that the battery output voltage is below the first threshold voltage. If the low battery condition is verified, an audible warning is generated, which is repeated at specified warning intervals. This audible warning affords an opportunity to the user for replacing the batteries in the device before loss of operation or degraded sound quality are experienced. Even after generation of the first warning signal, the electronic device continues to function essentially normally for some time. Once the electronic device enters a low battery power condition state, the audible warnings are repeated at specified warning intervals, and the battery output voltage is monitored and compared to a second threshold voltage at specified sampling intervals. If the preliminary warnings are unheeded by the user and the battery output voltage drops below the second threshold voltage, the system generates a final warning and shuts down the output stage of the electronic device. However, until this final warning is generated, the hearing aid device continues to function essentially normally, without at any instant compromising of the effective functioning of the device.

Apparatus and method for detecting a low-battery power condition and generating a user perceptible warning

In a serial interface for a programmable hearing aid, no address is provided for the data transferred to or read from the hearing aid, rather, for each instruction, the number of data words being transferred pursuant to each instruction and the beginning word are known in the controlled device. In the serial interface, the data is clocked into and out of the hearing aid on a serial data pin by a serial clock. Because no addresses are sent along with the data to the controlled device, the amount of data transferred to the hearing aid is significantly reduced, and no circuitry is required to save the address.

Two line variable word length serial interface

An analog-to-digital converter according to the present invention comprising a comparator having first and second inputs, and an output, the comparator comparing an analog input voltage at the first input to a tracking voltage at the second input to place a digital output on the comparator output in response thereto, a voltage switching matrix having an input connected to the output of the comparator and an output, an integrator having an input connected to the output of the voltage switching matrix and an output connected to the second input of the comparator to complete a feedback loop and to provide the tracking signal to the second input of the comparator, and a digital filter coupled to the output of the comparator, the digital filter to form a digital output corresponding to the analog input signal at the first input of the comparator.

Growing community of inventors

Sandy, UT, United States of America

Robert Sherman Green