UMA1021M/C2 Philips Semiconductors (Acquired by NXP), UMA1021M/C2 Datasheet - Page 46

• Manufacturer Part Number: UMA1021M/C2
• Description: UDA1380; Stereo Audio Coder-decoder For MD, CD And MP3
• Manufacturer: Philips Semiconductors (Acquired by NXP)

Philips Semiconductors
Table 59 Microphone input VGA gain setting bits
2003 Apr 04
Stereo audio coder-decoder
for MD, CD and MP3
7 to 4
BIT
VGA_CTRL3
3
2
1
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
SEL_LNA
SEL_MIC
SKIP_DCFIL
EN_DCFIL
SYMBOL
VGA_CTRL2
default value 0000
Line input select. A 1-bit value to set the multiplexer in the analog front-end to select
between the LNA or the enable-in input for the left ADC. When this bit is logic 0: select
line input. When this bit is logic 1: select LNA for the left ADC. Default value 0.
Microphone input select. A 1-bit value to set the multiplexer at the ADC right channel
output (on bit-stream level) which selects either the right channel data or the left
channel data. In case only the microphone input is used, the microphone signal can
be applied to the decimator for both left and right. When this bit is logic 0: select right
channel ADC. When this bit is logic 1: select left channel ADC (for instance for
microphone input). Default value 0.
DC filter bypass. A 1-bit value set to skip the DC filter which is just before the
decimator. This DC filter is there to compensate for the DC offset added in the ADC (to
remove idle tones from the audio band). This DC signal added (the DC dither) must
not be amplified in order to prevent clipping. Therefore this DC offset is removed first.
When this bit is logic 0: DC filter enabled. When this bit is logic 1: DC filter bypassed.
Default value 1.
DC filter enable. A 1-bit value set to enable the DC filter which is at the output of the
decimator (running at 1f
logic 1: DC filter enabled. Default value 0.
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
VGA_CTRL1
s
). When this bit is logic 0: DC filter disabled. When this bit is
46
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
DESCRIPTION
VGA_CTRL0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Product specification
LNA GAIN (dB)
UDA1380
0 (default)
10
12
14
16
18
20
22
24
26
28
30
2
4
6
8