Abstract

The management of unit element selections in a system that includes multiple unit elements. The system includes an element selection component that is configured so that each of the multiple elements is used the same number of times over a certain number of selection cycles. This preserves the first order noise shaping of the mismatch noise thereby keeping a high signal to noise ratio. In addition, the selection of the unit elements is not done in a periodic fashion. This allows the system to avoid tones within the signal band.

IPC Classes  ?

• H03M 1/66 - Digital/analogue converters

Abstract

An echo detection circuit that detects an echo by detecting the magnitude of a digitally mixed representation of the received acoustic signal and reference sine and cosine signals. That magnitude is then compared against an echo threshold to verify the presence or absence of an echo signal. A low pass filter with a configurable cut-off frequency may be used to define the selectivity of the echo detector.

IPC Classes  ?

• H04B 1/06 - Receivers

Abstract

A differential level shifter employs a variable current mirror to maintain a reference voltage at one output while the other output follows a differential input. Resistor networks allow postproduction trimming of load resistors and the current mirror, resulting in a precise and accurate output of the differential signal. An active cascode circuit enhances current mirror balance and high frequency operation.

IPC Classes  ?

• H03K 19/0175 - Coupling arrangementsInterface arrangements

Abstract

A switching circuit that transitions using a switch transistor. During the initial stages of a high-low transition, a control loop provides supplemental pre-charge to the gate of the switch transistor to reduce high-low switching delays. Once the current flowing through the switch transistor rises to a level causing the output voltage to change at specified speed threshold, a loop opening mechanism opens the loop. Further opening of the switch transistor in the high-low transition is taken care of by a relatively constant current source. At that point, no or negligible feedback current is used to charge the gate of the switch transistor. Low-high transitions may be performed in a similar complementary manner.

IPC Classes  ?

• H03K 17/687 - Electronic switching or gating, i.e. not by contact-making and -breaking characterised by the use of specified components by the use, as active elements, of semiconductor devices the devices being field-effect transistors