Datasheet
Functional Description
MC13783 Technical Data, Rev. 3.5
36 Freescale Semiconductor
4.3.6 Audio Control
4.3.6.1 Supply
The audio section is supplied from a dedicated regulator VAUDIO, except for the loudspeaker amplifier
Alsp which is directly supplied from the battery. A low power standby mode controlled by the standby pins
is provided for VAUDIO in which the bias current is reduced. The output drive capability and performance
are limited in this mode. The nominal output voltage for VAUDIO is 2.775 V. A 1uF (± 35%) bypass
capacitor is needed at the output of the VAUDIO regulator.
4.3.6.2 Bias and Anti-Pop
The audio blocks have a bias which can be enabled separately from the rest of the MC13783. When
enabled, the audio bias voltages can be ramped fast or slow to make any pop sub audio and therefore not
audible.
4.3.6.3 Arbitration Logic
The audio functions can be operated by both the primary and secondary SPI.
4.4 Battery Management
4.4.1 Battery Interface and Control
The battery interface is optimized for single charger input coming from a standard wall charger or from a
USB bus. The charger has been designed to support three different configurations where the charger and
USB bus share the same input pin (CHRGRAW): these are dual path charging, serial path charging, and
single path charging. In addition, provisions have been taken for a separate input configuration where the
charger and USB supply are on separate inputs. In all cases except for single path charging, the battery
interface allows for so called dead battery operation. An example of serial path charging is shown in
Section 4.4.1.1, “Serial Path Configuration Example,” on page 37.
This section includes the following subsections:
• Section 4.4.1.1, “Serial Path Configuration Example,” on page 37
• Section 4.4.1.2, “Charger Operation,” on page 38
• Section 4.4.1.3, “Coin Cell,” on page 38
The mode of operation for the charger interface is selected via the CHRGMOD1 and CHRGMOD0 pins
as given in Table 22.
Table 22. Charger Mode Selection
CHRGMOD1 CHRGMOD0 Charger Mode
Hi Z GND Dual Path
Hi Z Hi Z Single Path
Hi Z VATLAS Serial Path