Power Supplies; Serial Interface; Analog Inputs - Analog Devices EVAL-AD7124-4SDZ User Manual

EVAL-AD7124-4SDZ User Guide

POWER SUPPLIES

The evaluation board requires that an external power supply—
either a bench top supply or a wall wart (dc plug) supply—be
applied to J3 or J5 (see Table 3 for more information). Linear
regulators generate the required power supply levels from the
applied V rail. The regulators used are the
IN
and the ADP1720 (U4), which supply 3.3 V and 1.8 V,
respectively, to AV of the ADC. The 3.3 V
DD
delivers 3.3 V to the IOV pin of the AD7124-4.
DD
When a split power supply is used, the AV
applied from an external source via Connector J9. AV
IOV can also be provided via Connector J9. However, the 7 V
DD
to 9 V supply is still required because the on-board reference
(ADR4525) is supplied from this power supply.
Each supply is decoupled at the point where it enters the board
and again at the point where it connects to each device (see the
schematics shown in Figure 26 to Figure 29 to identify
decoupling points).
Table 3. Required External Power Supply
Power Supply
(V ) Applied To Voltage Range
IN
J3 7 V to 9 V
J5 7 V to 9 V
1 Only a single supply is required, either J3 or J5. This supply can be selected using LK2.
ADP1720-3.3 (U7)
ADP1720 (U10)
voltage must be
SS
and
DD
1
Function
Bench top supply to the evaluation board. Supplies LDOs that create the 3.3 V and 1.8 V rails. It also
supplies the ADR4525 external reference. Ensure that LK2 is set to Position A when the external
power supply is applied to this connector.
Wall wart (dc plug) supply to the evaluation board. Supplies LDOs that create the 3.3 V and 1.8 V rails.
It also supplies the ADR4525
power supply is applied to this connector.
Rev. 0 | Page 7 of 29

SERIAL INTERFACE

The EVAL-AD7124-4SDZ
serial peripheral interface (SPI) to the Blackfin®
on the EVAL-SDP-CB1Z. There are four primary signals: CS,
SCLK, DIN, and DOUT/ RDY (all are inputs, except for
DOUT/ RDY , which is an output).
To operate the EVAL-AD7124-4SDZ
AD7124-4 serial interface lines can be disconnected from the
120-pin header by removing the 0 Ω links, R9 through R13. The
test points can then be used to fly-wire the signals to an alternative
digital capture setup.

ANALOG INPUTS

The EVAL-AD7124-4SDZ
in two ways:
•
Using J6 and J11, the green screw in terminal connectors
•
Using the A0 and A1 SMB/SMA footprints on the
evaluation board, which connect to the AIN4 and AIN5
analog inputs.
The AD7124-4 EVAL+ Software
the ADC.
external reference. Ensure that LK2 is set to Position B when the external
UG-855
evaluation board connects via the
ADSP-BF527
in standalone mode, the
primary analog inputs can be applied
is set up to analyze dc inputs to