Evaluation Board Hardware; Hardware Overview; Reference - Analog Devices EVAL-ADAQ7980SDZ User Manual

UG-1060

EVALUATION BOARD HARDWARE

+7.5V/+5.0V
REFERENCE CIRCUITRY
ADR4550/ADR3433
VIN+

HARDWARE OVERVIEW

Figure 16 shows a simplified block diagram of the
ADAQ7980SDZ. The evaluation board features the
and peripheral circuitry that evaluates the device. This section
gives an overview of the ADAQ7980
how the operation parameters can be configured on the
ADAQ7980SDZ hardware.
The EVAL-ADAQ7980SDZ
options for many of the major operation nodes of the ADAQ7980.
The evaluation board provides two on-board reference options
(5 V and 3.3 V), pads to set multiple configurations for the
ADC driver, and various power supply options. The following
sections describe these options in detail.
Figure 28 to Figure 32 show the evaluation board schematics. The
evaluation board is a flexible design that enables the user to adjust
compensation components and operate the evaluation board from
an adjustable bench top power supply.
+9V
DC
PLUG
+5.0V/+3.3V
+7.5V/+5.0V
V+
VCM
PD_REF
IN+
IN–
AMP_OUT
V–
PD_AMP
–2.5V/0V
EVAL-ADAQ7980SDZ EVALUATION BOARD
Figure 16. EVAL-ADAQ7980SDZ
EVAL-
ADAQ7980
operation and describes
allows a variety of configuration
POWER SUPPLY CIRCUITRY
ADP7118, ADP2370, ADP7182
+7.5V –2.5V +5.0V
REF_OUT LDO_OUT
REF
LDO
10µF
2.2µF
20Ω
ADC
1.8nF
ADAQ7980
ADCN GND
PD_LDO
PD_AMP
PD_REF
Simplified Block Diagram

REFERENCE

The reference setting of the
input) determines the full-scale input range at the integrated ADC
inputs which determines the output range of the integrated ADC
driver (the range of the AMP_OUT pin). For example, if using a
5 V reference, then the
EVAL-
AMP_OUT pin between 0 V and 5 V before the signal overranges.
The REF pin of the
reference buffer. The REF_OUT pin is the output of the reference
buffer and the reference node utilized by the integrated ADC.
When utilizing the reference buffer, drive the REF pin to the
desired reference voltage for the system. See the ADAQ7980/
ADAQ7988
voltage operation.
The EVAL-ADAQ7980SDZ
the ADR4550BRZ
3.3 V. Either of these references can be routed to the REF pin of the
ADAQ7980
board.
In addition to the on-board
references, the
supply the reference externally through Pin 5 on the
P6 terminal block.
Rev. 0 | Page 8 of 30
EVAL-ADAQ7980SDZ User Guide
+3.3V
+7.5V/+5.0V
VDD
+5V
PD_LDO
+3.3V
VIO
SDI
SCK
SDO
ADSP-BF527
CNV
EVAL-SDP-CB1Z
ADAQ7980
ADAQ7980 can convert signals on the
ADAQ7980 is the input to the integrated
data sheet for more information regarding reference
has two reference devices installed:
supplying 5 V and the
by means of jumpers and links on the evaluation
ADR4550BRZ
EVAL-ADAQ7980SDZ
USB
(the voltage set at the REF
ADR3433ARJZ supplying
and ADR3433ARJZ
provides the option to