User guide

AC701 Evaluation Board www.xilinx.com 73
UG952 (v1.1) January 30, 2013
Feature Descriptions
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.
Figure 1-46 shows the XADC header J19 connections.
X-Ref Target - Figure 1-45
Figure 1-45: Header XADC_VREF Voltage Source Options
FPGA
U1
VAUX0N
VAUX0P
VAUX8N
VAUX8P
V
REF (1.25V)
V
REFN
VCCADC
GNDADC
V
N
V
P
DXP
DXN
UG952_c1_39_101612
100Ω
1 nF
100Ω
100Ω
1 nF
100Ω
To
Header
J49
Dual Use IO
(Analog/Digital)
100Ω
1 nF
100Ω
To
Header
J19
100 nF
XADC_AGND
REF3012
U35
Out In
Gnd
J42
XADC_AGND
Internal
Reference
XADC_VREF to
XADC Header J19.11
10 μF
Ferrite Bead
100 nF
1 nF
Ferrite Bead
J10
J9
Star Grid
Connection
J54
XADC_VCC
XADC_VCC
XADC_AGND
GND
V
REFP
XADC_VREFP
ADP123
U10
Out
In
Gnd
XADC_AGND
10 μF
XADC_VCC Header J49
100 nF
XADC_AGND
XADC_VCC
J43
Ferrite Bead
VCCAUX
VCC5V0
10 μF
XADC_VCC5V0 to
XADC Header J19.13
1.8V 150 mV max
J53
Filter 5V Supply
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