WM8991 datasheet(79/174 Pages) WOLFSON

79 / 174 page

Pre-Production

WM8991

PP, May 2008, Rev 3.1

LINE OUTPUT CONFIGURATIONS

The line outputs LON, LOP, RON and ROP are each driven by different output mixers as described

below.

The LOP and ROP pins output a mix of LIN12 input PGA, RIN12 input PGA and either LOMIX or

ROMIX outputs.

The LON output is a mix of ROMIX, LOMIX and a phase-inverted copy of LOP.

The RON output is a mix of LOMIX, ROMIX and a phase-inverted copy of ROP.

Volume control of LOMIX and ROMIX is available in all cases above via LOPGA and ROPGA. An

additional -6dB attenuation option is provided on LOP and ROP outputs.

The outputs LON, LOP, RON and ROP are capable of driving line loads only. Single ended output is

possible on all these output simultaneously. Differential output is also possible between LOP and

LON and between ROP and RON.

Typical applications for the line outputs (single-ended or differential) are:

•

Handset or headset microphone output to external voice CODEC

•

Stereo line output

•

Output to external speaker driver(s) to support stereo loudspeakers

Some example line output configurations are shown below.

Figure 36 Stereo Line Out (A)

Figure 37 Differential Output of MIC PGA

Figure 38 Stereo Line Out (B)

Figure 39 Differential Output to Speaker Driver

WM8991 Datasheet(PDF) 79 Page - Wolfson Microelectronics plc