AD7718_15 Datasheet, PDF (13/44 Pages) Analog Devices – 8-/10-Channel, Low Voltage

Pin No Mnemonic
21
CS
22
RDY
23
DOUT
24
DIN
25
DGND
26
DV_DD
27
XTAL2
28
XTAL1
AD7708/AD7718
Function
Chip Select Input. This is an active low logic input used to select the AD7708/AD7718. CS can
be used to select the AD7708/AD7718 in systems with more than one device on the serial bus or
as a frame synchronization signal in communicating with the device. CS can be hardwired low,
allowing the AD7708/AD7718 to be operated in 3-wire mode with SCLK, DIN, and DOUT
used to interface with the device.
RDY is a logic low status output from the AD7708/AD7718. RDY is low when valid data exists
in the data register for the selected channel. This output returns high on completion of a read
operation from the data register. If data is not read, RDY will return high prior to the next update
indicating to the user that a read operation should not be initiated. The RDY pin also returns
low following the completion of a calibration cycle. RDY does not return high after a calibration
until the mode bits are written to enabling a new conversion or calibration.
Serial data output with serial data being read from the output shift register of the ADC. The output
shift register can contain data from any of the on-chip data, calibration or control registers.
Serial Data Input with serial data being written to the input shift register on the AD7708/AD7718
Data in this shift register is transferred to the calibration or control registers within the ADC
depending on the selection bits of the Communications register.
Ground Reference Point for the Digital Circuitry.
Digital Supply Voltage, 3 V or 5 V Nominal.
Output from the 32 kHz Crystal Oscillator or Resonator Inverter.
Input to the 32 kHz Crystal Oscillator or Resonator Inverter.
PIN CONFIGURATION
AIN7 1
28 XTAL1
AIN8 2
27 XTAL2
AV_DD
AGND
REFIN1(–)
REFIN1(+)
AIN1
3
26 DV_DD
4 _AD7708/ 25 DGND
5 _AD7718 24 DIN
6 _{TOP VIEW} 23 DOUT
7 ^{(Not to Scale)} 22 _RDY
AIN2 8
21 CS
AIN3 9
20 SCLK
AIN4 10
19 _RESET
AIN5 11
18 P1
AINCOM 12
17 AGND
REFIN2(+)/AIN9 13
16 P2
REFIN2(–)/AIN10 14
15 AIN6
REV. 0
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