wm8918 Wolfson Microelectronics plc, wm8918 Datasheet - Page 63

• Manufacturer Part Number: wm8918
• Description: Ultra Low Power Dac For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

Production Data
OUTPUT SIGNAL PATH
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The outputs HPOUTL and LINEOUTL are normally derived from the Left DAC output, whilst the
outputs HPOUTR and LINEOUTR are normally derived from the Right DAC output, as illustrated in
Figure 37. A multiplexer is provided on each output path to select the BYPASSL or BYPASSR
analogue input signals in place of the DAC outputs.
A feedback path for common mode noise rejection is provided at HPOUTFB and LINEOUTFB for the
Headphone and Line outputs respectively. This pin must be connected to ground for normal
operation.
Each analogue output can be separately enabled; independent volume control is also provided for
each output. The output signal paths and associated control registers are illustrated in Figure 37.
See “Analogue Outputs” for details of the external connections to these outputs.
Figure 37 Output Signal Path and Control Registers
BYPASSL
BYPASSR
DAC L
DAC R
CHARGE PUMP
AVDD
Servo
DC
DCVDD
LINEOUTR_BYP_ENA
LINEOUTL_BYP_ENA
HPOUT and LINEOUT
drivers
HPR_BYP_ENA
HPL_BYP_ENA
M
U
M
M
U
M
U
X
U
X
X
X
PD, Rev 4.0, September 2010
HPOUTL_MUTE
HPOUT_VU
HPOUTLZC
HPOUTL_VOL
(-57dB to +6dB, 1 dB steps)
HPOUTR_MUTE
HPOUT_VU
HPOUTRZC
HPOUTR_VOL
(-57dB to +6dB, 1 dB steps)
LINEOUTL_MUTE
LINEOUT_VU
LINEOUTLZC
LINEOUTL_VOL
(-57dB to +6dB, 1 dB steps)
LINEOUTR_MUTE
LINEOUT_VU
LINEOUTRZC
LINEOUTR_VOL
(-57dB to +6dB, 1 dB steps)
LINEOUTR_PGA_ENA
LINEOUTL_PGA_ENA
HPR_PGA_ENA
HPL_PGA_ENA
HPOUTR
HPOUTL
HPOUTFB
LINEOUTR
LINEOUTL
LINEOUTFB
WM8918
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