AD7708 Analog Devices, AD7708 Datasheet - Page 13

• Manufacturer Part Number: AD7708
• Description: 16-Bit 8/10-Channel, Low Voltage, Low Power, Sigma Delta ADC
• Manufacturer: Analog Devices

Specifications of AD7708

• Resolution (bits): 16bit
• # Chan: 10
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni,SE-Uni
• Ain Range: (2Vref/PGA Gain) p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: SOIC,SOP

Pin No
21
22
23
24
25
26
27
28
Mnemonic
CS
RDY
DOUT
DIN
DGND
DV
XTAL2
XTAL1
DD
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.
REFIN2(–)/AIN10
REFIN2(+)/AIN9
REFIN1(–)
REFIN1(+)
AINCOM
PIN CONFIGURATION
AGND
AV
AIN7
AIN8
AIN1
AIN2
AIN3
AIN4
AIN5
DD
10
11
12
13
14
6
7
1
2
3
4
5
8
9
(Not to Scale)
AD7708/
AD7718
TOP VIEW
28
27
26
25
24
23
22
21
20
19
18
17
16
15
XTAL1
XTAL2
DV
DGND
DIN
DOUT
RDY
CS
SCLK
RESET
P1
AGND
P2
AIN6
DD
AD7708/AD7718