ATSAM3S-EK Atmel, ATSAM3S-EK Datasheet - Page 19

• Manufacturer Part Number: ATSAM3S-EK
• Description: KIT EVAL FOR ATSAM3S4C
• Manufacturer: Atmel
• Series: SAM3Sr
• Type: MCUr

Specifications of ATSAM3S-EK

• Contents: Board, Cables, Power Supply
• Silicon Manufacturer: Atmel
• Core Architecture: ARM
• Core Sub-architecture: Cortex-M3
• Kit Contents: Board
• Features: TFT Colour LCD Display, SD/MMC Interface
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• For Use With/related Products: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.3.11
4.3.12
4.3.12.1 Analog Reference
SAM3S-EK Development Board 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 SAM3S UDP port is compliant with the Universal Serial Bus (USB) rev 2.0 Full Speed device speci-
fication. 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 SAM3S 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 2V5 voltage reference is based on an 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
PB10
PB11
AT91SAM3S
AT91SAM3S
R110
R110
R112
R112
R114
R114
R116
R116
FGND
47K
47K
68K
68K
27R
27R
27R
27R
ADVREF
DGND
RV2
RV2
V5.5MLA0603
V5.5MLA0603
C94
C94
10pF
10pF
1
ADVREF
8
9
J15
J15
USB Micro B
USB Micro B
5V
5V
DGND
D-
D-
C5
C5
100nF
100nF
D+
D+
2
VCC33
ID
ID
DGND
G
G
JP2
JP2
LM4040-2.5
LM4040-2.5
MN2
MN2
RV1
RV1
V5.5MLA0603
V5.5MLA0603
7
6
+5V
DGND
R13
R13
2.2K
2.2K
FGND
Evaluation Kit Hardware
11031C–ATARM–30-Mar-11
4-11