EVAL-AD7797EBZ Analog Devices Inc, EVAL-AD7797EBZ Datasheet - Page 3

• Manufacturer Part Number: EVAL-AD7797EBZ
• Description: BOARD EVALUATION FOR AD7797
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7797EBZ

• Number Of Adc's: 1
• Number Of Bits: 24
• Sampling Rate (per Second): 123
• Data Interface: Serial
• Inputs Per Adc: 1 Differential
• Input Range: ±VREF/128
• Power (typ) @ Conditions: 1.6mW @ 123SPS
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7797
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

EVALUATION BOARD HARDWARE
POWER SUPPLIES
The AD7797 evaluation board is powered via the 5 V supply
from the USB connector, J1. This 5 V supply can be used to
power the
on-board ADP3303, a high precision, low power, 3.3 V output
voltage regulator, can also be used. Alternatively, the AD7797 can
be powered using an external 3 V or 5 V power supply via J3.
LINKS
There are five link options that must be set for the required
operating setup before using the evaluation board. The
functions of these link options are outlined in Table 1.
Table 1. Evaluation Board Link Settings
Link
LK1, LK2
LK3, LK4
LK5
Table 2. Initial Link and Switch Positions
Link No.
LK1, LK2
LK3, LK4
LK5
Table 3. Socket Functions
Socket
AIN+
AIN−
REFIN+
REFIN−
J2
AD7797
Default Position
In
In
B
Position
In
In
B
Description
Subminiature BNC (SMB) connector. The analog input signal for the AIN(+) input of the AD7797 is applied to this socket.
Subminiature BNC (SMB) connector. The analog input signal for the AIN(−) input of the AD7797 is applied to this socket.
Subminiature BNC (SMB) connector. This socket is used in conjunction with REFIN− to apply an external reference to the
AD7797. The voltage for the REFIN(+) input of the AD7797 is applied to this socket.
Subminiature BNC (SMB) connector. This socket is used in conjunction with REFIN+ to apply an external reference to the
AD7797. The voltage for the REFIN(−) input of the AD7797 is applied to this socket.
8-pin (2 × 4) straight header. This socket is used in conjunction with the prototype area to interface any signal to the AD7797.
directly. A 3.3 V regulated voltage from the
Description
AIN(+) and AIN(−) are shorted to AV
The reference voltage is set to 3.3 V (AV
The 3.3 V supply is used as AV
Description
These links are used to connect the AIN(+) and AIN(−) inputs to a reference voltage, which equals AV
With these links removed, an external voltage can be applied to AIN using the SMB connectors.
AV
and REFIN(−) is connected to GND. To use another reference source, remove LK3 and LK4.
LK5 is used to select the power source for AV
supply, supplied via J3. LK5 in Position B selects the 3.3 V regulated output from the on-board ADP3303
voltage regulator. LK5 in Position C selects the 5 V supply from the USB connector, J1.
DD
can be used as a reference for the AD7797. With LK3 and LK4 in place, AV
DD
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for the AD7797.
DD
/2.
DD
).
SETTING UP THE EVALUATION BOARD
Care should be taken before applying power and signals to the
evaluation board to ensure that all link positions are set per the
required operating mode. Table 2 shows the position in which
all the links are initially set.
SOCKETS
There are five sockets relevant to the operation of the AD7797
on this evaluation board. The functions of these sockets are
outlined in Table 3.
DD
on the AD7797. LK5 in Position A selects an external power
DD
is connected to REFIN(+)
EVAL-AD7797
DD
/2.