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Component Descriptions and Connections
UG0209 User Guide Revision 7.1
13
5
Component Descriptions and Connections
5.1
VAREF Connections
The SmartFusion cSoC has one external VAREF input pin for each of the ADCs in the device. These are
VAREF0 for ADC0 and VAREF1 for ADC1, as shown in the following figure. The internal VAREF is
brought out as an output. This is available as the VAREFOUT header J24.
Figure 3 •
VAREFOUT to VAREF0 and VAREF1
On the A2F-EVAL-KIT-2 board, the VAREF0 and VAREF1 inputs are hardwired to the VAREFOUT output
of the SmartFusion cSoC, as shown in the following figure. This means you should not drive these inputs
from any external source. Three headers J5, J8, and J24 are provided to monitor the VAREF0, VAREF1
and VAREFOUT for any debug purposes.
Figure 4 •
VAREF0 and VAREF1 Inputs of FPGA
5.2
Current Sensing Circuit
A current sensing circuit is provided on the SmartFusion Evaluation Kit board for applications using the
embedded current monitor. Current monitoring is performed across the AC0 and AT0 pins. The current
sensing circuit is for the 3.3 V voltage rail, as shown in the following figure.
Figure 5 •
Current Sensing
5.3
PWM Circuit
The PWM RC circuit depicted in
page 14 can be used with Microsemi
CorePWM instantiated in the FPGA fabric to generate various voltage waveforms. These voltage
VAREF_OUT
ADC0
DACOUT0
DACOUT0
VAREF_OUT
ADC3
ADC4
ADC5
DACOUT0
ADC2
AGND
AGND
AGND
AGND
AGND
AGND
VAREF0
VAREF1
1
2
J5
HEADER 1x2
J5
HEADER 1x2
1
2
J8
HEADER 1x2
J8
HEADER 1x2
C61
10uF-0805
C61
10uF-0805
C63
10uF-0805
C63
10uF-0805
GNDVAREF
U15
VAREF
OUT
T15
ADC2
V9
ADC3
AB8
ADC4
U12
ADC5
V12
ADC0
Y9
ADC1
AA8
SDD0
V7
A2F200M3F-FGG484
A2F200M3F-FGG484
C234
NL-0.1uF-0402
C234
NL-0.1uF-0402
C62
10uF-0805
C62
10uF-0805
R501
1K,1%-0603
R501
1K,1%-0603
C244
0.1uF-0402
C244
0.1uF-0402
VAREF0
VAREF1
VAREF_OUT
J24
HEADER 2X2
3
4
1
2
VAREF_OUT
VAREF_OUT
AT0
AT2
VAREF0
VAREF1
R194
1K,1%-0603
R194
1K,1%-0603
C204
0.1uF-0402
C204
0.1uF-0402
C208
0.1uF-0402
C208
0.1uF-0402
TM0
W8
VAREF1
AB11
VAREF0
U10
TM2
AB12
Q
Q
R131
1K,1%-0603
R131
1K,1%-0603
AT0
AC0
V3P3
R6
100R,1%-0805
R6
100R,1%-0805
R7
5K36-0805
R7
5K36-0805
1
3
2
50K_POT
3352P-1-503LF
50K_POT
3352P-1-503LF
D17
DL4007-Melf
D17
DL4007-Melf