AD7988-1 Analog Devices, AD7988-1 Datasheet - Page 8

• Manufacturer Part Number: AD7988-1
• Description: 16-Bit, 100ksps, Ultra Low Power 16-Bit SAR ADC
• Manufacturer: Analog Devices

Specifications of AD7988-1

• Resolution (bits): 16bit
• # Chan: 1
• Sample Rate: 100kSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (Vref) p-p,5V p-p,Uni (Vref),Uni 5.0V
• Pkg Type: SOP

AD7988-1/AD7988-5
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
Table 6. Pin Function Descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
1
AI = analog input, DI = digital input, DO = digital output, and P = power.
Mnemonic
REF
VDD
IN+
IN−
GND
CNV
SDO
SCK
SDI
VIO
EP
Figure 4. 10-Lead MSOP Pin Configuration
GND
VDD
REF
IN+
IN–
1
2
3
4
5
Type
AI
P
AI
AI
P
DI
DO
DI
DI
P
AD7988-1/
AD7988-5
(Not to Scale)
TOP VIEW
1
Description
Reference Input Voltage. The V
should be decoupled closely to the REF pin with a 10 μF capacitor.
Power Supply.
Analog Input. It is referred to IN−. The voltage range, for example, the difference between IN+ and IN−, is
0 V to V
Analog Input Ground Sense. Connect to the analog ground plane or to a remote sense ground.
Power Supply Ground.
Convert Input. This input has multiple functions. On its leading edge, it initiates the conversions and
selects the interface mode of the part: chain mode or CS mode. In CS mode, the SDO pin is enabled when
CNV is low. In chain mode, the data should be read when CNV is high.
Serial Data Output. The conversion result is output on this pin. It is synchronized to SCK.
Serial Data Clock Input. When the part is selected, the conversion result is shifted out by this clock.
Serial Data Input. This input provides multiple features. It selects the interface mode of the ADC as
follows:
Chain mode is selected if this pin is low during the CNV rising edge. In this mode, SDI is used as a data
input to daisy-chain the conversion results of two or more ADCs onto a single SDO line. The digital data
level on SDI is output on SDO with a delay of 16 SCK cycles.
CS mode is selected if SDI is high during the CNV rising edge. In this mode, either SDI or CNV can enable
the serial output signals when low.
Input/Output Interface Digital Power. Nominally at the same supply as the host interface (1.8 V, 2.5 V, 3 V,
or 5 V).
Exposed Pad. The exposed pad can be connected to GND.
10
9
8
7
6
VIO
SDI
SCK
SDO
CNV
REF
.
Rev. A | Page 8 of 24
REF
range is from 2.4 V to 5.1 V. It is referred to the GND pin. The GND pin
NOTES
1. THE EXPOSED PAD CAN BE CONNECTED TO GND.
Figure 5. 10-Lead LFCSP (QFN) Pin Configuration
GND
VDD
REF
IN+
IN–
1
2
3
4
5
AD7988-1/
AD7988-5
(Not to Scale)
TOP VIEW
10 VIO
9
8
7
6
SDI
SCK
SDO
CNV
Data Sheet