User Guide

PAMS Technical Documentation 3 - Audio System
NPE-4
Original ãNokia Corporation. Page 3-7
DC Characteristics
The audio relevant supply voltages are shown in the following table:
Audio Function Description
Audio control
The audio control and processing is done by the UEM, which contains the audio codec
and the UPP contains DSP blocks, handling and processing the audio data signals.
The audio block diagram is presented in , page .
The UEM supports three microphone inputs and two earphone outputs. The inputs can be
taken from an internal microphone, a headset microphone or a handsfree-unit / Carkit
microphone. The microphone signals from different sources are connected to separate
inputs at the UEM ASIC. Inputs for the microphone signals are differential type.
MIC1 and EAR in/output are used for the internal microphone input and Earpiece output.
The Headset or handsfree unit / Carkit audio is connected to the MIC2 input / HF (single
ended) output. The MIC3/XEAR is connected to GND and not used in the NPE-4 project.
Input and output selection and gain control is performed inside the UEM ASIC (register
AudioCtrl (Gain and routing) and MicBias (microphone bias selection).
Additional gain is added in the DSP SW. This gain is controled by adaptive algorithms
(AGC, DRC, ALWE and AEC) and set as a function of background noise, signal level and
Table 2:
Supply Voltages
Line
Symbol
Minimum TYP. /
Nominal
Maximum Unit Notes
Vana 2.7 2.78 2.86 V (Mic bias buffer)
0,005 80 mA Min. due to regulator stability
VBAT 3.1 (SW)
(2.9 (HW))
3.6 5.1 (SW)
(5.4 (HW))
V (Buzzer and Vibra driver). Min and
max due to SW cut off.
Vflash1 2.7 2.78 2.86 V (DLR3, HEADINT and HOOKINT pull
up)
0.005 70 mA Min. due to regulator stability
0.005 1.5 mA Sleep
Vflash2 2.7 2.78 2.86 V (DLR3)
0.005 40 mA Min. due to regulator stability
VIO 1.72 1.8 1.88 V (HOOKINT level shifter)