Datasheet
Data Sheet AD7982
Rev. B | Page 7 of 24
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
REF
1
VDD
2
IN+
3
IN–
4
GND
5
VIO
10
SDI
9
SCK
8
SDO
7
CNV
6
AD7982
T
OP
VIEW
(Not to Scale)
06513-004
Figure 4. 10-Lead MSOP Pin Configuration
06513-005
1REF
2VDD
3IN+
4IN–
5GND
10 VIO
NOTES
1. THE EXPOSED PAD SHOULD BE CONNECTED
TO GND. THIS CONNECTION IS NOT REQUIRED
TO MEET THE ELECTRICAL PERFORMANCES.
9 SDI
8 SCK
7 SDO
6 CNV
AD7982
TOP VIEW
Figure 5. 10-Lead QFN (LFCSP) Pin Configuration
Table 6. Pin Function Descriptions
Pin
No. Mnemonic Type
1
Description
1 REF AI Reference Input Voltage. The REF range is 2.4 V to 5.1 V. This pin is referred to the GND pin and should
be decoupled closely to the GND pin with a 10 µF capacitor.
2 VDD P Power Supply.
3 IN+ AI Differential Positive Analog Input.
4 IN− AI Differential Negative Analog Input.
5 GND P Power Supply Ground.
6 CNV DI 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.
7 SDO DO Serial Data Output. The conversion result is output on this pin. It is synchronized to SCK.
8 SCK DI Serial Data Clock Input. When the part is selected, the conversion result is shifted out by this clock.
9 SDI DI Serial Data Input. This input provides multiple features. It selects the interface mode of the ADC as follows:
Chain mode is selected if SDI 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 18 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. If SDI or CNV is low when the conversion is complete, the busy indicator
feature is enabled.
10 VIO P 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).
EPAD Exposed Pad. For the lead frame chip scale package (LFCSP), the exposed pad should be connected to GND.
this connection is not required to meet the electrical performances.
1
AI = analog input, DI = digital input, DO = digital output, and P = power.