WM8903LGEFK/RV Wolfson Microelectronics, WM8903LGEFK/RV Datasheet - Page 40

• Manufacturer Part Number: WM8903LGEFK/RV
• Description: Audio CODECs ULTRA LOW PWR HI FI CODEC
• Manufacturer: Wolfson Microelectronics

Specifications of WM8903LGEFK/RV

• Audio Codec Type: Stereo Codec
• No. Of Adcs: 2
• No. Of Dacs: 2
• No. Of Input Channels: 6
• No. Of Output Channels: 8
• Adc / Dac Resolution: 24bit
• Sampling Rate: 96kHz
• Operating Temperature Range: -40°C To +85°C
• Rohs Compliant: Yes
• Adcs / Dacs Signal To Noise Ratio: 96dB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8903
DIGITAL MICROPHONE INTERFACE
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In applications where the Current Detect threshold is close to the level of the current spikes, the
probability of false detections is reduced by the hysteresis and digital filtering described above.
Note that the filtering algorithm provides only limited rejection of very high current spikes at
frequencies less than or equal to the hook switch detect measurement frequency, or at frequencies
equal to harmonics of the hook switch detect measurement frequency.
The MICBIAS Hook Switch digital filtering is illustrated in Figure 27. Example control sequences for
configuring the Interrupts functions for MICBIAS current detection events are described in the
“Applications Information” section.
Figure 27 MICBIAS Hook Switch Detect Filtering
The WM8903 supports a two-channel digital microphone interface. The two-channel audio data is
multiplexed on the DMIC_DAT input and clocked by the DMIC_LR output.
The Digital Microphone Input, DMIC_DAT, is provided on the GPIO2/DMIC_DAT pin. The associated
clock, DMIC_LR, is provided on the GPIO1/DMIC_LR pin.
The Digital Microphone Input is selected as input by setting the ADC_DIG_MIC bit. When the Digital
Microphone Input is selected, the ADC input is bypassed.
The Digital Microphone Interface configuration is illustrated in Figure 28.
Note that that care must be taken to ensure that the respective digital logic levels of the microphone
are compatible with the digital input thresholds of the WM8903. The digital input thresholds are
referenced to DBVDD, as defined in “Electrical Characteristics”. It is recommended to power the
digital microphones from the same DBVDD supply as WM8903.
PD, Rev 4.0, September 2010
Production Data
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