公开(公告)号：GB2502557A

公开(公告)日：2013-12-04

申请号：GB201209600

申请日：2012-05-30

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： LESSO JOHN PAUL ,  PENNOCK JOHN LAURENCE

IPC: H03M1/06 ,  H03M1/10 ,  H03M1/18 ,  H03M1/60

Abstract: Analogue-to-digital converters based on voltage-to-frequency conversion are susceptible to gain changes due to manufacturing and thermal variations in the controlled oscillators. In a differential ADC of this type the digital output signal Dout is derived from the difference in pulse rates from the two signal-controlled oscillators 202,203. A further pulse count Cout independent of the differential input signal, such as a sum or average of the pulse rates from the two oscillators, may be used to derive a regulating signal SFB for controlling the gain of the VCO/ CCO pair or the clocked integration period (figure 24) of the counters in block 204. Alternatively the digital output may be scaled by the regulating signal (SFF, figure 25). Clipping due to signal overload may be overcome by reducing the gain of the VCO/CCO pair when the input signals are excessive (figures 29-31).

公开(公告)号：CA2882321A1

公开(公告)日：2013-06-20

申请号：CA2882321

申请日：2012-12-14

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： LESSO JOHN PAUL ,  FRITH PETER JOHN ,  PENNOCK JOHN LAURENCE

IPC: H04L25/49

Abstract: This application relates to methods and apparatus for transfer of multiple digital data streams, especially of digital audio data over a single communications link such as a single wire. The application describes audio interface circuitry comprising a pulse- length-modulation(PLM) modulator (204). The PLM is responsive to a plurality of data streams (PDM-R, PDM-L), to generate a seriesof data pulses (PLM)with a single data pulse having a rising and falling edge in each of a plurality of transfer periods defined by a first clock signal (TCLK). The timing of the rising and falling edgeof each data pulse is dependent upon on a combination of the then current data samples from the plurality of data streams. The duration and position of the data pulse in the transfer window in effect defines a data symbol encoding the data. Circuitry for receiving and extracting the data is also disclosed. An interface receives the stream of data pulses (PLM) and data extraction circuitry (202) samplesthe data pulseto determine which of the possible data symbols the pulse representsand determines a data value for at least one received data stream.

公开(公告)号：GB2486698A

公开(公告)日：2012-06-27

申请号：GB201021801

申请日：2010-12-23

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： LESSO JOHN PAUL ,  PENNOCK JOHN LAURENCE ,  FRITH PETER JOHN

IPC: H02M3/07

Abstract: A bipolar output charge pump circuit 100 is provided having a network of switching paths 110 for selectively connecting an input node VV and a reference node VG for connection to an input voltage, a first pair of output nodes VP, VN, two pairs of flying capacitor nodes CF1A, CF1B; CF2A, CF2B, and a controller 120 for controlling the switching of the network of switching paths. The controller is operable to control the network of switching paths when in use with two flying capacitors CFI, CF2 connected to the two pairs of flying capacitor nodes, to provide a first mode and a second mode when in use with two flying capacitors connected to the flying capacitor nodes, wherein at least the first mode corresponds to a bipolar output voltage of +/- 3VV, +/- VV/5 or +/-VV/6, where VV is the input voltage.

公开(公告)号：GB2482444A

公开(公告)日：2012-02-01

申请号：GB201118390

申请日：2007-03-30

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： PENNOCK JOHN LAURENCE

IPC: H03K5/19 ,  G11B20/10 ,  H03G3/34

Abstract: A pattern detection circuit 30 comprises means for detecting a silence pattern in a received bit stream and distinguishes between a plurality of predetermined silence patterns. A means generates a control signal which corresponds to the detected silence pattern from the plurality of silence patterns. The silence patterns may comprise equal numbers of ones and zeros, such as four ones and four zeros and may be a repeated bit sequence. The control signal may control an audio reproduction device and may cause the audio reproduction device to power down to conserve energy or enter respective different standby modes when detecting a first or second silence pattern. The audio reproduction system may include a playback device where the playback device is adapted to alter a silence pattern on a storage medium, such as a super audio compact disc, in order to transmit signaling information. The audio reproduction system may also include a receiver device having a loudspeaker such as a wireless headphone connected to the playback device over a wireless link.

公开(公告)号：GB2475633B

公开(公告)日：2011-10-05

申请号：GB201102622

申请日：2006-12-22

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： LESSO JOHN PAUL ,  PENNOCK JOHN LAURENCE ,  FRITH PETER JOHN

IPC: H03F1/02 ,  H02M3/07 ,  H03F3/187 ,  H03F3/213

公开(公告)号：GB2444988B

公开(公告)日：2011-07-20

申请号：GB0625799

申请日：2006-12-22

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： LESSO JOHN PAUL ,  PENNOCK JOHN LAURENCE ,  FRITH PETER JOHN

IPC: H03F1/02 ,  H03F99/00 ,  H02M3/07 ,  H03F1/52 ,  H03F3/187 ,  H03F3/213

Abstract: An electronic audio amplifier circuit, operable in two modes and a battery powered portable audio apparatus incorporating the circuit; and associated apparatuses and methods. When in the first mode the audio apparatus is designed for the direct driving of headphones or a speaker. When in the second mode the audio apparatus is designed to drive a line input of an external amplifying apparatus with a signal that having a higher voltage amplitude for a given signal content than when driving headphone or a speaker. The circuit has common output stage circuitry for use in both modes, and a dual mode power supply circuit, ideally a charge pump circuit, for supplying the output stage in the first mode with a lower supply voltage than in the second mode.

公开(公告)号：GB2441358B

公开(公告)日：2011-07-06

申请号：GB0617139

申请日：2006-08-31

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： LESSO JOHN PAUL ,  PENNOCK JOHN LAURENCE

IPC: H02M3/155

公开(公告)号：GB2475636A

公开(公告)日：2011-05-25

申请号：GB201103080

申请日：2006-12-22

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： LESSO JOHN PAUL ,  PENNOCK JOHN LAURENCE ,  FRITH PETER JOHN

IPC: H03F1/02 ,  H02M3/07 ,  H03G1/00

Abstract: The power supply 80 for an audio amplifier output stage 40 provides voltages which vary in dependence on a volume control signal S2 which controls the gain of amplifier stage 20. The power supply comprises a flying capacitor charge pump circuit (figures 5b, 16b) which provides opposite polarity supplies from a single polarity input. The charge pump may be fed through a controllable DC-DC buck converter (1010, figure 26), which can be bypassed when the battery voltage is low. The supply voltages may be regulated (figure 15). The charge pump may have dual modes (figures 10, 16b) wherein it can be controlled to provide outputs which are either equal to the input voltage or a fraction of the input voltage. Only one flying capacitor is required to provide a split supply of +/- VDD/2.

公开(公告)号：GB2466776A

公开(公告)日：2010-07-07

申请号：GB0823665

申请日：2008-12-30

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： PENNOCK JOHN LAURENCE ,  STEELE COLIN FINDLAY ,  STOJANOVIC GORAN

IPC: H03F3/70 ,  B81B3/00 ,  B81B7/02 ,  H01L23/485 ,  H01L23/522 ,  H03F1/56 ,  H04R19/01

Abstract: The effect of a parasitic capacitance between a bond pad 126 and the IC substrate is reduced by applying a bootstrapping signal from amplifier 128 to a diffusion region 402 placed under the bond pad. The effective reduction in the parasitic capacitance reduces the attenuation of signals from a capacitive sensor such as a MEMS electret microphone, which may be located on a second IC 100. Bootstrapping may be applied to the parasitic capacitance of the corresponding bond pad on the second IC (122, figures 1 and 10) by use of a similar diffusion region.

公开(公告)号：GB2395849B

公开(公告)日：2005-11-09

申请号：GB0227553

申请日：2002-11-26

Applicant: WOLFSON LTD ,  WOLFSON MICROELECTRONICS PLC

Inventor： PENNOCK JOHN LAURENCE ,  GRANVILLE EDWARD MAUGER

IPC: H03G1/00 ,  H03K17/00 ,  H03K17/693 ,  H03G3/02

Abstract: The present invention relates to analogue selectors, also known as analogue multiplexers, for audio equipment input source selection. The present invention provides an analogue input selector for selecting one of a number of analogue source devices. The selector comprises a plurality of input connections for coupling to the input sources, each said input connection being connected to a gain controller having at least zero and one or more non-zero gains, said input connection not including a semiconductor switch. Preferably the gain controllers are implemented using MOSFETs which are held at a voltage which is independent of the signal voltage.