Audio Interface; Usb Device - Atmel SAM4E-EK User Manual

4.3.14 Audio Interface

The Atmel SAM4E-EK evaluation kit supports mono/stereo audio driven by a TPA0223 audio amplifier connected to two
DAC channels of the microcontroller.
The TPA0223 is a 2W mono Bridge-Tied-Load (BTL) amplifier designed to drive speakers with as low as 4Ω
impedance. The amplifier can be reconfigured on the fly to drive two stereo Single-Ended (SE) signals into head
phones.
Figure 4-14. Headphone output.
+5V
2
JP14
+3V3
PB13
C63 0.47uF
DAC0
TP6
Test Pad SQ-40TH
AUDIO_OUTL
C67 0.47uF
Using a readily available 1/8-in. (3.5mm) stereo headphone jack, the control switch (pin4 and pin5 in J10) is closed
when no plug is inserted. When closed, a 100kΩ/1kΩ divider pulls the ST/MN input low. When a jack plug is inserted,
the 1kΩ resistor is disconnected and the ST/MN input is pulled high. The mono speaker (J9 connector) is also
physically disconnected from the RO/MO+ output so that no sound is heard from the speaker while the headphones are
inserted.
When works as stereo mode make sure JP15, JP16, and JP17 are disconnected.

4.3.15 USB device

The SAM4E16 UDP port is compliant with the Universal Serial Bus (USB) rev 2.0 Full Speed device specification. J11 is
a micro B-type receptacle for USB device.
Both 27Ω resistors R82 and R83 build up 90Ω differential impedance together with the (embedded) 6Ω output
impedance of the SAM4E16 full speed channel drivers.
R80 and R81 build up a divider bridge from VBUS +5V to implement plug-in detection (5V level gets lowered to a PIO
compatible 3.3V level) through PC21.
FB2
BN03K314S300R VDD_AMP
+
C59 C60 C61
1uF 10uF 100nF
AGND
R65 33K
JP15 R66 47K
C64 0.47uF R67 33K
JP16 R71 47K
R72 33K
JP18
2
AUDIO OUT
MN8
TPA0223DGQ
3 6
VDD RO/MO+
AGND
10
LO/MO-
5
RIN
1 7
MONO-IN ST/MN
2
SHUTD0WN
4
C65
BY PASS
9
LIN
8
GND
R73 0R
AGND
AGND
PB14
J10
5 Phonejack Stereo 3.5
C58 220uF-TAN-6.3V
4
3
R63 1K
2
1
R64 1K
C62 220uF-TAN-6.3V
AGND
VDD_AMP
R68 100K R69 100K
R70 100K
0.47uF
JP17
AGND AGND
SAM4E-EK User Guide
42067B−SAM4E−04/2013
J9
1
2
C66
1uF
AGND
17