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

Pre-Production
w
HIGH-PASS FILTER (HPF)
A digital high-pass filter is applied by default to the ADC path to remove DC offsets. This filter can
also be programmed to remove low frequency noise in handheld applications (e.g. wind noise,
handling noise or mechanical vibration). This filter is controlled using the ADC_HPF_ENA and
ADC_HPF_CUT register bits (see Table 11).
In hi-fi mode the high pass filter is optimised for removing DC offsets without degrading the bass
response and has a cut-off frequency of 3.7Hz at fs=44.1kHz.
In voice mode the high pass filter is optimised for voice communication and it is recommended to
program
ADC_HPF_CUT=10 at fs=16kHz).
Table 11 ADC High-pass Filter Control Registers
Table 12 ADC High-pass Filter Cut-off Frequencies
Filter response plots for the ADC high-pass filter are shown in “Digital Filter Characteristics”.
R38 (26h)
ADC Digital 0
Rate (kHz)
REGISTER
ADDRESS
Sample
11.025
16.000
22.050
24.000
32.000
44.100
48.000
88.200
96.000
8.000
the
cut-off
BIT
6:5
4
0.7
0.9
1.3
1.9
2.0
2.7
3.7
4.0
7.4
8.0
frequency
00
ADC_HPF_CUT
[1:0]
ADC_HPF_ENA
LABEL
below
Value of ADC_HPF_CUT bits
Cut-off frequency (Hz)
127
175
190
253
348
379
696
758
300Hz
64
88
01
DEFAULT
00
1
(e.g.
ADC_HPF_CUT=11
ADC Digital High Pass Filter Cut-
Off Frequency (fc)
00 = Hi-fi mode (fc=4Hz at
fs=48kHz)
01 = Voice mode 1 (fc=127Hz at
fs=16kHz)
10 = Voice mode 2 (fc=130Hz at
fs=8kHz)
11 = Voice mode 3 (fc=267Hz at
fs=8kHz)
(Note: fc scales with sample rate fs.
See Table 12 for cut-off frequencies
at all supported sample rates)
ADC Digital High Pass Filter Enable
0 = disabled
1 = enabled
1414
1540
130
178
258
354
386
514
707
770
10
PP, Rev 3.1, August 2009
DESCRIPTION
at
1063
1464
1594
2928
3188
267
367
532
733
798
11
WM8903
fs=8kHz
39
or