发明名称 |
AUDIO ACCESSORY CIRCUITRY AND METHOD COMPATIBLE WITH BOTH MSFT MODE AND DIGITAL COMMUNICATION MODE |
摘要 |
An audio accessory key detection system (40) includes a host circuit (2-3) coupled to communicate via a microphone line (7) with an accessory circuit (3-3) in either a MSFT mode or a digital communication mode. Depletion mode transistors (44-1,2,3) in the accessory circuit are coupled between keys (15-1,2,3) of the accessory circuit, respectively. The depletion mode transistors are allowed to remain conductive for MSFT mode operation. For digital communications mode operation, the host circuit sends a command via the microphone line to a key detector and controller circuit (29A) in the accessory circuit. In response, a voltage is generated to turn the depletion mode transistors off so as to allow digital communications mode operation between the accessory circuit and the host circuit. |
申请公布号 |
US2017019733(A1) |
申请公布日期 |
2017.01.19 |
申请号 |
US201615277579 |
申请日期 |
2016.09.27 |
申请人 |
TEXAS INSTRUMENTS INCORPORATED |
发明人 |
Fan Ball;Wang Wenpang David;Graves Christopher Michael |
分类号 |
H04R3/00 |
主分类号 |
H04R3/00 |
代理机构 |
|
代理人 |
|
主权项 |
1. A process of operating an audio accessory key detection system comprising:
(a) in the absence of receiving an initial command on a microphone line coupled to a microphone and bias circuit, coupling keys to the microphone line; and (b) upon receiving an initial command on the microphone line, disconnecting the keys from the microphone line and sending over the microphone line a signal indicating an operation of a key. |
地址 |
Dallas TX US |