Enhanced Product AD7980-EP
Rev. A | Page 7 of 12
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
REF
1
VDD
2
IN+
3
IN–
4
VIO
10
SDI
9
SCK
8
SDO
7
GND
5
CNV
6
AD7980-EP
TOP VIEW
(Not to Scale)
09304-004
Figure 4. 10-Lead MSOP Pin Configuration
Table 6. Pin Function Descriptions
Pin No. Mnemonic Type
1
Description
Reference Input Voltage. The REF range is from 2.4 V to 5.1 V. It is referred to the GND pin. This pin should
be decoupled closely to the pin with a 10 µF capacitor.
2 VDD P Power Supply.
3 IN+ AI
Analog Input. It is referred to IN−. The voltage range, for example, the difference between IN+ and IN−, is
0 V to V
REF
.
4 IN− AI Analog Input Ground Sense. To be connected to the analog ground plane or to a remote sense ground.
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, or
CS mode. In CS mode, it enables the SDO pin when 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.
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 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; 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).
1
AI = analog input, DI = digital input, DO = digital output, and P = power.
