Sonic Innovations, Inc.

Microtune (texas), Inc.

Benjamin Edward Nise

Carver A Mead

Trevor A Blyth

Robert Sherman Green

David A Wayne

Xialoing Fang

Disclosed are systems and methods which provide phase shifting of signals while minimizing signal attenuation associated with providing such phase shifting. Preferred embodiments provide a compact polyphase filter structure in which the geometry of the polyphase filter both minimizes parasitic capacitance and signal transmission paths therein. A polyphase filter of a preferred embodiment utilizes a radial pinwheel structure providing a geometry in which successive circuit components are disposed very near one another and in an orientation to accommodate very short connections therebetween. Embodiments may include the use of a buffer at the outputs of the polyphase filter circuit to reduce the amount of parasitics associated with the polyphase filter.

Efficient polyphase filter having a compact structure

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

An analog-to-digital converter comprises a modulator connected to an analog input signal, a decimator connected to the output of the modulator, a normalizer connected to the output of the modulator and forming a digital output signal, and a programmable gain control circuit connected to the output of the normalizer and providing feedback gain control to the modulator and the decimator.

Passive switched capacitor delta analog-to-digital converter with

In a double-sided pulse width modulator, an amplifier has a first input connected to a first reference potential, a second input, and an output. A first bank of storage elements have a first terminal connected to the second input of the amplifier, and a second terminal. A first bank of switches have an output terminal connected to a second terminal of the storage elements, an input terminal, and a control terminal connectable by a timing gate to an output of the modulator and a polarity control bit for a first value to be input into the input terminals. A feedback storage element is connected in parallel with a first timing switch between the second input of the amplifier and the output of the amplifier. A comparator has a first input connected to a second reference potential, a second input, a timing enable input, and an output. A second bank of storage elements have a first terminal connected to the second input of the comparator, and a second terminal. A second timing switch is connected in parallel with a first one of the storage elements of the second bank of storage elements between the output of the amplifier and the second input of the comparator. A second bank of switches have a first terminal connected to one of the storage elements in the second bank of storage elements other than the one storage element, a second terminal connected to the output of the amplifier, and a control terminal connected to a second input value. A current source is connected to the second input of the comparator to discharge a value having a duration proportional to the product of the first input value and the second input value to form the output of the modulator at the output of the comparator.

Growing community of inventors

Plano, TX, United States of America

Benjamin Edward Nise