WM8903LGEFK/RV Wolfson Microelectronics, WM8903LGEFK/RV Datasheet - Page 39

• 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

Production Data
w
The hook switch detection measurement frequency and the detection delay time t
in the “Electrical Characteristics” section.
The WM8903 Interrupt function is described in the “Interrupts” section. Example control sequences
for configuring the Interrupts functions for MICBIAS current detection events are described in the
“Applications Information” section.
A clock is required for the digital filtering function. This requires:
Table 8 MICBIAS Current Detect Clocking
Any MICBIAS Current Detect event (accessory insertion/removal or hookswitch press/release) which
happens while one or more of the clocking criteria is not satisfied (for example during a low power
mode where the CPU has disabled MCLK) will still be detected, but only after the clocking conditions
are met. An example is illustrated in Figure 26, where the mic is inserted while MCLK is stopped.
Figure 26 MICBIAS Detection events without MCLK
MICROPHONE HOOK SWITCH DETECTION
The possibility of spurious hook switch interrupts due to ambient noise conditions can be removed by
careful understanding of the microphone behaviour under extremely high sound pressure levels or
during mechanical shock, and by correct selection of the MICBIAS resistor value; these factors will
affect the level of the MICBIAS AC current spikes.
R22 (16h)
Clock Rates 2
R108 (6Ch)
Write
Sequencer 0
REGISTER
ADDRESS
Mic insertion event
•
•
•
MCLK is present
CLK_SYS_ENA = 1
WSMD_CLK_ENA
MCLK
GPIO
IRQ
BIT
2
8
CLK_SYS_ENA
WSMD_CLK_E
NA
LABEL
happens at any time
(1) insertion event
during this period
DEFAULT
0
0
t
DET
System Clock enable
0 = Disabled
1 = Enabled
Write Sequencer / Mic Detect Clock
Enable.
0 = Disabled
1 = Enabled
(2) insertion indicated t
after MCLK re-started
PD, Rev 4.0, September 2010
DESCRIPTION
SHORT
WM8903
are detailed
DET
39