UDA1380TTN2 NXP Semiconductors, UDA1380TTN2 Datasheet - Page 13

• Manufacturer Part Number: UDA1380TTN2
• Manufacturer: NXP Semiconductors

Specifications of UDA1380TTN2

• Lead Free Status / Rohs Status: Compliant

NXP Semiconductors
8.2
The analog front-end of the UDA1380 consists of one
stereo ADC with a selector in front of it (see Fig.6). Using
this selector one can either select the microphone input
with the microphone amplifier (LNA) with a fixed 29 dB
gain and VGA (no PGA, since a real microphone amplifier
is much better with respect to noise), or the line input which
has a PGA for having 0 or 6 dB gain (for supporting 1 and
2 V (RMS) input). The PGA also provides gain control from
0 to 24 dB in steps of 3 dB.
Remark:
• The input impedance of the PGA (line input) is 12 kΩ, for
8.2.2
The LNA is equipped with a VGA. The function of the VGA
is to have additional variable analog gain from 0 to 30 dB
in steps of 2 dB. This provides more flexibility in the choice
of the microphone.
2004 Apr 22
handbook, full pagewidth
the LNA this is 5 kΩ
Stereo audio coder-decoder
for MD, CD and MP3
Pin numbers for UDA1380HN in parentheses.
ADC analog front-end
LNA
WITH
VGA
VINM
VINR
VINL
(29)
(27)
(31)
1
31
3
PGA
PGA
LNA
Fig.6 Analog front-end.
SDC
SDC
SDC
13
SEL_LNA
8.2.1
The following Power-down modes and functional modes
are supported:
• Power-down mode in which the power consumption is
• Line input mode, in which the PGA can be used
• Microphone mode, in which the rest of the non-used
• Mixed PGA and LNA mode: one line input and one
More information on the analog frond-end is given in
Section 8.11.1.
8.2.3
For the line input it is preferable to have 0 dB and 6 dB gain
settings in order to be able to apply both 1 and 2 V (RMS)
input signals, using a series resistance. For this purpose a
PGA is used which has 0 to 24 dB gain, in steps of 3 dB.
very low (only leakage currents)
In this mode there is no reference voltage at the line
input
PGAs and ADCs are powered-down
microphone input.
ADC
ADC
A
A
PPLICATIONS AND
PPLICATIONS WITH
SEL_MIC
MGU530
bitstream
right
bitstream
left
P
2 V (
OWER
RMS
-
DOWN MODES
Product specification
)
INPUT
UDA1380