Evaluation Board Hardware; Hardware Link Options - Analog Devices EVAL-AD4858FMCZ User Manual

User Guide

EVALUATION BOARD HARDWARE

The AD4858 is a fully buffered, 8-channel simultaneous sampling,
20-bit 1 MSPS DAS with differential, wide common mode range
inputs. The AD4858 has an on-chip low drift 4.096 V internal volt-
age reference, but, optionally, it also accepts an external reference
applied through the REFIO pin and provided on-board (LTC6655).
The device operates from different power rails, provided through
on-board LDOs as described in
to connect external supplies exists and is explained in
Table 1. Jumper Details with Factory Default Setting
Link Default Position
JODIFF to J7DIFF Not inserted
J0+ to J7+ Not inserted
J0− to J7− Not inserted
JV12V A
JSHIFT A
JVCC A
JVEE A
JVDDH A
JVDD A
JVDDL Not inserted
JVIO Not inserted
analog.com
Power Supplies section. An option
Table 1.
Function
Offset Calibration Jumper. Inserting the JODIFF to J7DIFF jumper link allows short-circuiting the corresponding pair of
inputs in order to measure the AD4858 offset and/or perform and offset calibration.
Analog Input to Ground Connection. Insert the J0+ to J7+ jumper link to connect to the AGND pin, the corresponding
positive analog input.
Analog Input to Ground Connection. Insert the J0− to J7− jumper link to connect to the AGND pin, the corresponding
negative analog input.
The JV12V link selects the power supply source for the evaluation board.
In Position A, the unregulated supply to the on-board LDOs is taken from the ZedBoard 12 V supply.
In Position B, the unregulated external supply to the on-board LDOs is taken from the V12V_EXT connector.
The JSHIFT link selects the power supply type for the AD4858.
In position A, the V pin = +24 V and the V
CC
In position B, the V pin = +44 V and the V
CC
If not inserted, the V pin = +24 V and the V
CC
The JVCC link selects the V
In position A, the V pin is provided by the on board
CC
In position B, the V pin is provided though VCC_EXT connector.
CC
The JVEE link selects the V
In position A, the V pin is provided by the on board LT8330 DC-to-DC converter.
EE
In position B, the V pin is provided though VEE_EXT connector.
EE
The JVDDH link selects the V
In position A, the V pin is provided by the on board
DDH
In position B, the V pin is provided though VDDH_EXT connector.
DDH
If not inserted, V pin can be tied to the AGND pin by inserting an R40 resistor. To disable the internal LDO, tie the V
DDH
pin to the GND pin. With the regulator disabled, connect the V
through the JVDDL link.
The JVDD link selects the V
In position A, the V pin is provided by the on board LT1761 5 V LDO.
DD
In position B, the V pin is provided though VDD_EXT connector.
DD
The JVDDL link selects the V
In position A, the V pin is provided by the on-board LT1761 1.8 V LDO. To use this configuration, tie the V
DDL
ground through the JVDDH link.
In position B, the V pin is provided though the VDDL_EXT connector. To use this configuration, tie the V
DDL
ground through the JVDDH link.
If not inserted, the internal LDO is used for the JVDDH link to be in position A or B.
The JVIO link selects the V
Alternatively, the V pin can be supplied from either the on-board LDOs or an external supply.
IO
In position A, the V pin is provided by the on board LT1761 LDO with an output voltage dependent on the JVIO_LDO link.
IO
The R66 resistor (shown in
In position B, the V pin is provided though VIO_EXT connector. The R66 resistor is unsoldered.
IO
Note the field programmable gate array (FPGA) image provided works at 2.5 V digital level, so use caution when changing
the default position of the JVIO link jumper.

HARDWARE LINK OPTIONS

Table 1 details the link option functions and the default power link
options. The EVAL-AD4858FMCZ can be powered from different
sources, as described in the
the power supply required for the EVAL-AD4858FMCZ comes from
the ZedBoard controller board. The power supply is regulated by
the on-board regulators that generate the required bipolar supplies.
pin = −24 V.
EE
pin = −4 V.
EE
pin = −4 V.
EE
pin supply source.
CC
LT8330 DC/DC converter.
pin supply source.
EE
pin supply source.
DDH
LT1761 2.5 V LDO.
DDL
pin supply source.
DD
pin supply source.
DDL
pin supply source. If not inserted, the V
IO
Figure 20) is unsoldered.
EVAL-AD4858
Power Supplies section. By default,
pin to an external supply in the range of 1.71 V to 1.89 V
pin is taken from the ZedBoard (default).
IO
DDH
pin to
DDH
pin to
DDH
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