EVAL-AD7718EB Analog Devices Inc, EVAL-AD7718EB Datasheet - Page 4

• Manufacturer Part Number: EVAL-AD7718EB
• Description: BOARD EVAL FOR AD7718
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD7718EB

• Number Of Adc's: 1
• Number Of Bits: 24
• Sampling Rate (per Second): 1.37k
• Data Interface: Serial
• Inputs Per Adc: 10 Single Ended
• Input Range: ±2.5 V
• Power (typ) @ Conditions: 3.84mW @ 3 V
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: AD7718
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

EVAL-AD7718-EB
4
5
6
7-8
9
10
11-12
13
14-18
19-30
31-36
S O C K E T S
There are eighteen sockets relevant to the operation of the AD7718 on this evaluation board. The functions of
these sockets are outlined in Table 4.
Table 4. Socket Functions
Socket
J4
J1
S C L K
N C
DV
N C
D O U T
N C
D G N D
N C
Function
9-way D-Type connector used to interface to other systems.
36-way centronics connector used to interface to PC via parallel printer port.
DD
18
36
Chip Select. The signal on this pin is buffered before being applied to the
AD7718.
hard-wired low, the AD7718 can operate in its three-wire interface mode with SCLK,
DIN and DOUT used to interface to the device.
systems with more than one device on the serial bus or as a frame synchronization signal
in communicating with the AD7718.
Serial Clock. The signal on this pin is buffered before being applied to the SCLK pin
of the AD7718. An external serial clock is applied to this input to read/write serial data
from/to the AD7718. This serial clock can be continuous with all data transmitted in
a continuous train of pulses. Alternatively, it can be non-continuous with the information
being transmitted to the AD7718 in smaller batches of data.
Logic Input. The signal on this pin is buffered before being applied to the
of the AD7718. The
modulators across a number of AD7718s. While
filter, the filter control logic and the calibration control logic are held in a reset state.
No Connect. These pins are not connected on the evaluation board.
Digital Supply Voltage. This provides the supply voltage for the buffer chips, U3-U5,
which buffer the signals between the AD7718 and J1/J4.
Logic output. This is a buffered version of the signal on the AD7718
low on this output indicates that either the Main ADC or Auxiliary ADC has valid data
in their data register. The
of a full output word. If data is not read
indicating to the user that a read operation should not be initiated. The
returns low after the completion of a calibration cycle. The
NOR of the RDY0 and RDY1 bits in the Status register. If one of the ADCs is disabled
the
the mode bits are written to enabling a new conversion or calibration.
No Connect. These pins are not connected on the evaluation board.
Serial Data Output. This is a buffered version of the signal on the AD7718 DOUT pin.
Serial Data Output with serial data obtained from the output shift register on the
AD7718. The output shift register can contain information from of the on-chip registers
depending on the register selection bits of the Communications Register.
No Connect. These pins are not connected on the evaluation board.
Ground reference point for digital circuitry. Connects to the DGND plane on the
evaluation board.
No Connect. These pins are not connected on the evaluation board.
Fig. 3:
pin reflects the active ADC.
36-way Centronics (SKT2) Pin Configuration
is an active low Logic Input used to select the AD7718. With this input
input allows for synchronisation of the digital filters and
- 4 -
pin will return high upon completion of a read operation
does not return high after a calibration until
will return high prior to the next update
can be used to select the device in
is low, the nodes of the digital
19
1
pin is effectively the
pin. A logic
pin of the
pin also
pin
Rev. B