EP 1536663 A1 20050601 - Headset interface circuit
Title (en)
Headset interface circuit
Title (de)
Schnittstellenschaltung für Kopfhörer
Title (fr)
Circuit d'interface pour casque d'écoute
Publication
Application
Priority
EP 03292966 A 20031128
Abstract (en)
An interface circuit (200) for a headset (100) comprising one or more loudspeakers (SPL,SPR) and a microphone (M) makes use of a phantom ground approach for supplying a reference ground potential to the loudspeakers and microphone in the headset. The headset interface circuit (200) outputs for the microphone (M) within the headset (100) a stacked biasing voltage (VMBiasSt) that is substantially equal to the sum of the phantom ground potential and the normal biasing voltage (VMBias) required across the microphone (M). When the headset amplifier and interface circuit (200) is provided within a radiotelephone, for example, the radiotelephone's audio ground (VAG) can be used to provide the phantom ground voltage. <IMAGE>
IPC 1-7
IPC 8 full level
H04R 5/04 (2006.01); H04R 5/033 (2006.01)
CPC (source: EP)
H04R 5/04 (2013.01); H04R 5/033 (2013.01); H04R 2201/107 (2013.01)
Citation (search report)
- [X] US 2002186834 A1 20021212 - KATO TAKENORI [JP], et al
- [A] GB 2387979 A 20031029 - NEC TECHNOLOGIES [GB]
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
DOCDB simple family (publication)
DOCDB simple family (application)
EP 03292966 A 20031128