Analog Interface; Analog Reference; Analog Input - Atmel SAM4E-EK User Manual

Figure 4-15. USB.
FGND
PC21
R80
R81
PB10
R82
PB11
R83

4.3.16 Analog interface

4.3.16.1

Analog reference

The 3.0V voltage reference is based on a LM4040 (Precision Micropower Shunt Voltage Reference).
This ADVREF level can be set as 3.0V or 3.3V via the jumper JP3.
Figure 4-16. Analog Vref.
ADVREF
C13 C14
100nF 1uF
4.3.16.2

Analog input

•
The BNC connector CN2 is connected to the AEF0_AD4 or AFE1_AD0 (selected by JP40) as a single external
analog input
•
The BNC connectors CN3, CN4 are connected to AFE0_AD10 and AFE0_AD11 as a differential external
analog input. A low pass filter is optional by close 1-2 pins of JP21, JP22, JP24, and JP25
•
Each BNC input has an on-board 50Ω resistor termination that can be applied by closing jumper JP20, JP23 or
JP26
•
A 10kΩ potentiometer (VR1) is also connected to the AFE0_AD5 implement an easy access to ADC
programming and debugging (or implement an analog user control like display brightness, volume, etc.)
USB
J11
TBD USB Micro B
10
5V D- D+
8
9
RV1
V5.5MLA0603
47K
C75
68K 10pF
27R
27R
+3V3 +5V
JP3
2 R1
2.2K
MN1
LM4040AIM3X-3.0
11
ID G
7
6
RV2
V5.5MLA0603
FGND
SAM4E-EK User Guide
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