Abstract: A bipolar output charge pump circuit 100 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) and a second pair of output nodes (VQ, VM), and two pairs of flying capacitor nodes (CF1A, CF1 B; CF2A, CF2B), and a controller 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 (CF1, CF2) connected to the two pairs of flying capacitor nodes, to provide a first bipolar output voltage at the first pair of output nodes (VP, VN) and a second bipolar output voltage at the second pair of bipolar output nodes (VQ, VM).

Abstract: A signal amplifying circuit and associated methods and apparatuses, the circuit comprising: a signal path extending from an input terminal to an output terminal, a gain controller arranged to control the gain applied along the signal path in response to a control signal; an output stage within the signal path for generating the output signal, the output stage having a gain that is substantially independent of its supply voltage, and a variable voltage power supply comprising a charge pump for providing positive and negative output voltages, the charge pump comprising a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of the states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage.

Abstract: A bipolar output charge pump circuit 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 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 (CF1, 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.

Abstract: A bipolar output charge pump circuit 100 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) and a second pair of output nodes (VQ, VM), and two pairs of flying capacitor nodes (CF1A, CF1 B; CF2A, CF2B), and a controller 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 (CF1, CF2) connected to the two pairs of flying capacitor nodes, to provide a first bipolar output voltage at the first pair of output nodes (VP, VN) and a second bipolar output voltage at the second pair of bipolar output nodes (VQ, VM).

Abstract: An audio device is provided that is arranged for communication of data and signalling with a controller, signalling from the device to the controller being made in discrete time slots, the device comprising: a plurality of nodes, each assigned a priority value and each having one or more unsolicited response sources capable of generating an unsolicited response for transmission to the controller, wherein unsolicited responses generated from a particular node are assigned the priority value of that node; and unsolicited response management means operable to hold unsolicited responses generated by the plurality of nodes that are awaiting transmission to the controller, wherein when two or more unsolicited responses are awaiting transmission to the controller in the unsolicited response management means, the device is arranged to transmit the unsolicited response with the highest assigned priority value first, in the next free time slot.