WM8951L_07 WOLFSON [Wolfson Microelectronics plc], WM8951L_07 Datasheet - Page 29

• Manufacturer Part Number: WM8951L_07
• Description: Stereo ADC with Microphone Input and Clock Generator
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

Production Data
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USB MODE SAMPLE RATES
In USB mode the MCLK/crystal oscillator input is 12MHz only.
Notes:
1.
2.
3.
4.
The table above can be used to set up the device to work with various sample rate combinations. For
example if the user wishes to use the WM8951L in USB mode with the ADC sample rate at 48kHz
then the device should be programmed with BOSR = 0, SR3 = 0, SR2 = 0, SR1 = 0 and SR0 = 0.
The ADC will then operate with a Digital Filter of type 0, refer to Digital Filter Characteristics section
for an explanation of the different filter types.
The BOSR bit represents the base over-sampling rate. This is the rate that the WM8951L digital
signal processing is carried out at and the sampling rate will always be a sub-multiple of this. In USB
mode, with BOSR = 0, the base over-sampling rate is defined at 250fs, with BOSR = 1, the base
over-sampling rate is defined at 272fs. This can be used to determine the actual audio sampling rate
produced by the ADC.
Table 15 USB Mode Sample Rate Look-up Table
44.1 (Note 2)
88.2 (Note 3)
SAMPLING
8k not exact, actual = 8.021kHz
44.1k not exact, actual = 44.118kHz
88.1k not exact, actual = 88.235kHz
All other combinations of BOSR and SR[3:0] that are not in the truth table are invalid
(Note 1)
RATE
ADC
kHz
48
32
96
8
8
FREQUENCY
12.000
12.000
12.000
12.000
12.000
12.000
12.000
MCLK
MHz
BOSR
0
1
0
1
0
0
1
SR3
REGISTER SETTINGS
0
1
0
1
0
0
1
SAMPLE
RATE
SR2
0
0
0
0
1
1
1
SR1
0
0
1
1
1
1
1
PD Rev 4.1 December 2007
SR0
0
0
1
1
0
1
1
WM8951
DIGITAL
FILTER
TYPE
0
1
0
1
0
3
2
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