Dialog Semiconductor Gmbh

Dialog Semiconductor B.v.

Renesas Design (uk) Limited

Anthony Gribben

Mykhaylo Teplechuk

A signal amplifier includes a modulator circuit, a power converter and a H-bridge circuit. The modulator circuit generates a first logic signal by comparing an input signal with a first waveform and generates a second logic signal by comparing the input signal with a second waveform. The power converter provides a first voltage and a second voltage. The H-bridge circuit has a first input terminal to receive the first voltage, a second input terminal to receive the second voltage and a pair of output terminals for providing an output modulated voltage to a load. The H-bridge circuit generates the output modulated voltage using a primary modulation when the second logic signal is in a first logic state and using a secondary modulation when the second logic signal is in a second logic state.

Signal amplifier

An adaptive sample and hold circuit for signal amplifier range selection is presented. The adaptive sample and hold circuit has an input for receiving an input signal and an output for providing a sample-and-hold-voltage. It also includes a sample-and-hold-capacitor to generate the sample-and-hold-voltage from the input signal, and a range detector. The range detector is adapted to identify a range of the input signal and to adjust a voltage at the sample-and-hold-capacitor based on the range of the input signal to maintain the sample-and-hold-voltage within a predetermined voltage span.

Adaptive sample and hold circuit for signal amplifier range selection

A circuit and a method are provided for suppressing the pop and click noise during the power on and power off of Class D amplifiers. The technique also suppresses pops and clicks when the Class D amplifier enters or exits standby mode. A duplicate feedback network is used to establish the stable operating points, including offsets in the Class D circuit without turning on the outputs. The technique works by gradually propagating or dissipating the offset through the signal path of a Class D amplifier by swapping the differential outputs using switches to suppress pops and clicks when starting up and shutting down the amplifier.

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Edinburgh, United Kingdom

Anthony Gribben