WM8986GECO/V Wolfson Microelectronics, WM8986GECO/V Datasheet - Page 31

• Manufacturer Part Number: WM8986GECO/V
• Description: Audio Amplifiers Class D Headphone DAC + Line Out
• Manufacturer: Wolfson Microelectronics

Specifications of WM8986GECO/V

• Product: Class-D
• Output Power: 40 mW
• Thd Plus Noise: - 86 dB
• Operating Supply Voltage: 1.71 V to 3.6 V, 2.5 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Audio Load Resistance: 16 Ohms
• Minimum Operating Temperature: - 40 C
• Output Signal Type: Differential
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 1.71 V, 2.5 V
• Output Type: Differential
• Package / Case: QFN-28
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Production Data
OUTPUT SIGNAL PATH
Figure 19 DAC Digital Filter Path
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The BOOST stage is enabled under control of the BOOSTEN register bit.
Table 9 Input BOOST Enable Control
The WM8986 output signal paths consist of digital application filters, up-sampling filters, stereo Hi-Fi
DACs, analogue mixers, stereo headphone and stereo line/mono/midrail output drivers. The digital
filters and DAC are enabled by register bits DACENL and DACENR. The mixers and output drivers
can be separately enabled by individual control bits (see Analogue Outputs). Thus it is possible to
utilise the analogue mixing and amplification provided by the WM8986, irrespective of whether the
DACs are running or not.
The WM8986 DACs receive digital input data on the DACDAT pin. The digital filter block processes
the data to provide the following functions:
High performance sigma-delta audio DAC converts the digital data into an analogue signal.
The analogue outputs from the DACs can then be mixed with the various analogue inputs. The mix is
fed to the output drivers for headphone (LOUT1/ROUT1, LOUT2/ROUT2) or line (OUT3/OUT4).
OUT3 and OUT4 have additional mixers which allow them to output different signals to the line
outputs.
DIGITAL PLAYBACK (DAC) PATH
Digital data is passed to the WM8986 via the flexible audio interface and is then passed through a
variety of advanced digital filters as shown in Figure 19 to the hi-fi DACs. The DACs are enabled by
the DACENL/R register bits.
Table 10 DAC Enable Control
The WM8986 also has a Soft Mute function, which when enabled, gradually attenuates the volume of
the digital signal to zero. When disabled, the gain will ramp back up to the digital gain setting. This
function is enabled by default. To play back an audio signal, it must first be disabled by setting the
SOFTMUTE bit to zero.
R2 (02h)
Power
management
2
R3 (03h)
Power
Management 3
REGISTER
ADDRESS
REGISTER
ADDRESS
Digital volume control
Graphic equaliser and 3-D enhancement
A digital peak limiter.
Sigma-Delta Modulation
4
5
BIT
0
1
BIT
BOOSTENL
BOOSTENR
LABEL
DACENL
DACENR
LABEL
0
0
0
0
DEFAULT
DEFAULT
Left channel DAC enable
0 = DAC disabled
1 = DAC enabled
Right channel DAC enable
0 = DAC disabled
1 = DAC enabled
Left channel Input BOOST enable
0 = Boost stage OFF
1 = Boost stage ON
Right channel Input BOOST enable
0 = Boost stage OFF
1 = Boost stage ON
DESCRIPTION
DESCRIPTION
PD, Rev 4.1, June 2009
WM8986
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