WM8900LGEFK/RV Wolfson Microelectronics, WM8900LGEFK/RV Datasheet - Page 55

• Manufacturer Part Number: WM8900LGEFK/RV
• Description: Audio CODECs Ultra Low Power Hi-Fi CODEC
• Manufacturer: Wolfson Microelectronics

Specifications of WM8900LGEFK/RV

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Production Data
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LINEOUT_2L AND LINEOUT_2R OUTPUTS
The outputs LINEOUT_2L and LINEOUT_2R are independently controlled by the register bits
described in Table 39. The outputs can be independently muted and the volumes controlled in the
range -57dB to +6dB.
To allow simultaneous volume updates of left and right channels, output gains are not altered until
a 1 is written to the OUT2_VU bit.
To prevent "zipper noise", a zero-cross function is provided, so that when enabled, volume updates
will not take place until a zero-crossing is detected. In the event of a long period without zero-
crossings, a timeout function is available. When this function is enabled (using the TOCLK_ENA
register bit), the volume will update after the timeout period if no earlier zero-cross has occurred.
The timeout period is set by TOCLK_RATE. Note that this timer is the same timer as applied to the
Input PGA zero-cross function.
With the addition of small capacitors linking the LINEOUT_2L and LINEOUT_2R signals to the
Headphone driver, the HP_L and HP_R pins can drive a 16Ω or 32Ω headphone. The headphone
output is ground referenced and therefore no further capacitors are required and no headphone
click noise is produced when muting or un-muting. See “Ultra Low Power Ground-Referenced
Headphone Output” for further details.
The Line Output 2 Volume Control register fields are described in Table 39.
Table 39 LINEOUT_2L/ LINEOUT_2R Volume Control
See "Volume Updates" for more information on volume update bits, zero cross and timeout
operation.
R53 (35h)
Left OUT2
Control
R54 (36h)
Right OUT2
Control
REGISTER
ADDRESS
8
7
6
5:0
8
7
6
5:0
BIT
OUT2_VU
OUT2L_ZC
OUT2L_MUTE
OUT2L_VOL
[5:0]
OUT2_VU
OUT2R_ZC
OUT2R_MUTE
OUT2R_VOL
[5:0]
LABEL
0
0
1
111001
0
0
1
111001
DEFAULT
Left Channel LINEOUT2 Volume Update
Writing a 1 to this bit will cause left and
right LINEOUT2 volume to be updated
simultaneously
Left Channel LINEOUT2 Zero Cross
enable
0 = Change gain immediately
1 = Change gain on zero cross only
Left Channel LINEOUT2 Mute
0 = LINEOUT_2L Unmuted
1 = LINEOUT_2L Mute
Left Channel LINEOUT2 Volume Control
(-57dB -> +6dB in 1dB steps)
111111 = +6dB
000000 = -57dB
Right Channel LINEOUT2 Volume Update
Writing a 1 to this bit will cause left and
right LINEOUT2 volume to be updated
simultaneously
Right Channel LINEOUT2 Zero Cross
enable
0 = Change gain immediately
1 = Change gain on zero cross only
Right Channel LINEOUT2 Mute
0 = LINEOUT_2R Unmuted
1 = LINEOUT_2R Mute
Right Channel LINEOUT2 Volume Control
(-57dB -> +6dB in 1dB steps)
111111 = +6dB
000000 = -57dB
PD, August 2008, Rev 4.0
DESCRIPTION
WM8900
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