ATSAM4S-EK2 Atmel, ATSAM4S-EK2 Datasheet - Page 18

• Manufacturer Part Number: ATSAM4S-EK2
• Description: Development Boards & Kits - ARM EVAL KIT SAM4S8 & SAM4S16
• Manufacturer: Atmel

Specifications of ATSAM4S-EK2

• Rohs: yes
• Product: Evaluation Kits
• Tool Is For Evaluation Of: SAM4SD32C
• Core: ARM Cortex M4
• Interface Type: RS-232, USB
• Operating Supply Voltage: 5 V

4.3.11
4.3.12
4.3.12.1 Analog Reference
SAM4S-EK2 User Guide
USB Device
Analog Interface
Using a readily available 1/8-in. (3,5 mm) stereo headphone jack, the control switch is closed when no
plug is inserted. When closed, a 100-kOhm/1-kOhm divider pulls the ST/MN input low. When a jack plug
is inserted, the 1-kOhm resistor is disconnected and the ST/MN input is pulled high. The mono speaker
(J10 connector) is also physically disconnected from the RO/MO+ output so that no sound is heard from
the speaker while the headphones are inserted.
The SAM4SD32 UDP port is compliant with the Universal Serial Bus (USB) rev 2.0 Full Speed device
specification. J15 is a micro B-type receptacle for USB device.
Both 27-Ohm resistors R114 and R116 build up a 90-Ohm differential impedance together with the
(embedded) 6-Ohm output impedance of the SAM4SD32 full speed channel drivers.
R110 and R112 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.
Figure 4-14. USB
The 2.5V voltage reference is based on a LM4040 (Precision Micropower Shunt Voltage Reference).
This ADVREF level can be set as 2.5V or 3.3V via the jumper JP2.
Figure 4-15. Analog Vref
PC21
PB 10
PB 11
SAM4SD32
R1 10
R1 12
R1 14
R1 16
FG ND
47 K
68 K
27 R
27 R
ADVREF
DG ND
RV 2
V5 .5MLA0 603
C9 4
10 pF
1
ADVREF
10
8
9
J1 5
TB D
5V
DGND
US B Micro B
USB
D-
C5
C5
100nF
100nF
2
D+
VCC33
ID
JP2
JP2
LM4040-2.5
LM4040-2.5
DG ND
MN2
MN2
G
RV 1
V5 .5MLA0 603
DGND
+5V
11
7
6
R13
R13
2.2K
2.2K
FG ND
Evaluation Kit Hardware
11176A–ATARM–24-Sep-12
4-11