Xilinx AC701 User Manual page 75

X-Ref Target - Figure 1-46
U1
Dual Use IO
(Analog/Digital)
100Ω
VAUX0P
1 nF
VAUX0N
To
100Ω
Header
J49 100Ω
VAUX8P
1 nF
VAUX8N
100Ω
The AC701 board supports both the internal FPGA sensor measurements and the external
measurement capabilities of the XADC. Internal measurements of the die temperature,
VCCINT, VCCAUX, and VCCBRAM are available. The AC701 board VCCINT and
VCCBRAM are provided by a common 1.0 V supply.
Jumper J42 can be used to select either an external differential voltage reference
(XADC_VREF) or on-chip voltage reference (jumper J42 2–3) for the analog-to-digital
converter.
For external measurements an XADC header (J19) is provided. This header can be used to
provide analog inputs to the FPGA's dedicated VP/VN channel, and to the VAUXP[0]/
VAUXN[0], VAUXP[8]/VAUXN[8] auxiliary analog input channels. Simultaneous
sampling of Channel 0 and Channel 8 is supported.
A user-provided analog signal multiplexer card can be used to sample additional external
analog inputs using the 4 GPIO pins available on the XADC header as multiplexer address
lines.
AC701 Evaluation Board
UG952 (v1.2) August 28, 2013
XADC_VCC
FPGA
XADC_VCC
VCCADC
100 nF
Close to
Package Pins
XADC_AGND
GNDADC
XADC_AGND
J42
XADC_VREFP
V REFP
100 nF
Close to
Package Pins
V REFN
100Ω
V P
1 nF
V N
100Ω
DXP
DXN
Figure 1-46: Header XADC_VREF Voltage Source Options
Figure 1-47 shows the XADC header J19 connections.
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VCCAUX
Ferrite Bead
J43
XADC_VCC Header J49
1.8V 150 mV max
U10
ADP123
Out In
Gnd
10 µF
XADC_AGND
XADC_VREF to
XADC Header J19.11
U35
REF3012
V REF (1.25V)
Out In
Gnd
10 µF
Internal
Reference
Ferrite Bead
XADC_AGND
XADC_AGND
Star Grid
Connection
To
Header
J19
Feature Descriptions
XADC_VCC5V0 to
XADC Header J19.13
Ferrite Bead
J53
10 µF 100 nF 1 nF
Filter 5V Supply
Locate Components on Board
J54
XADC_VCC
J10
GND
J9
UG952_c1_39_101612
VCC5V0
75