Datasheet

Data Sheet AD7699
Rev. | Page 7 of 28
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
PIN 1
INDICATOR
1VDD
2REF
3REFIN
4GND
5GND
13 SCK
14 SDO
15 VIO
12 DIN
11 CNV
6
IN4
7
IN5
8
IN6
01
COM
9
IN7
81
IN2
91
IN3
02
VDD
71
IN1
61
IN0
TOP VIEW
(Not to Scale)
AD7699
07354-004
NOTES
1. THE EXPOSED PADDLE IS NOT CONNECTED INTERNALLY.
FOR INCREASED RELIABILITY OF THE SOLDER JOINTS,
IT IS RECOMMENDED THAT THE PAD BE SOLDERED TO
THE GND PLANE.
Figure 4. Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Type
1
Description
1, 20 VDD P Power Supply. Nominally 4.5 to 5.5 V and should be decoupled with 10 F and 100 nF capacitors.
2 REF AI/O
Reference Input/Output. See the Voltage Reference Output/Input section.
When the internal reference is enabled, this pin produces 4.096 V. When the internal reference is disabled
and the buffer is enabled, REF produces a buffered version of the voltage present on the REFIN pin
(VDD – 0.5 V maximum) useful when using low cost, low power references.
For improved drift performance, connect a precision reference to REF (0.5 V to VDD).
For any reference method, this pin needs decoupling with an external 10 F capacitor connected as
close to REF as possible. See the Reference Decoupling section.
3 REFIN AI/O
Internal Reference Output/Reference Buffer Input. See the Voltage Reference Output/Input section.
When using the internal reference, the internal unbuffered reference voltage is present and needs
decoupling with a 0.1 F capacitor.
When using the internal reference buffer, apply a source between 0.5 V and 4.096 V that is buffered to
the REF pin as previously described.
4, 5 GND P Power Supply Ground.
6 to 9 IN4 to IN7 AI Analog Input Channel 4, Analog Input Channel 5, Analog Input Channel 6, and Analog Input Channel 7.
10 COM AI
Common Channel Input. All input channels, IN[7:0], can be referenced to a common-mode point of 0 V
or V
REF
/2 V.
11 CNV DI
Conversion Input. On the rising edge, CNV initiates the conversion. During conversion, if CNV is held
high, the busy indictor is enabled.
12 DIN DI
Data Input. This input is used for writing to the 14-bit configuration register. The configuration register
can be written to during and after conversion.
13 SCK DI
Serial Data Clock Input. This input is used to clock out the data on SDO and clock in data on DIN in an
MSB first fashion.
14 SDO DO
Serial Data Output. The conversion result is output on this pin and synchronized to SCK. In unipolar
modes, conversion results are straight binary; in bipolar modes, conversion results are twos
complement.
15 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).
16 to 19 IN0 to IN3 AI Analog Input Channel 0, Analog Input Channel 1, Analog Input Channel 2, and Analog Input Channel 3.
21 (EPAD)
Exposed
Paddle
(EPAD)
The exposed paddle is not connected internally. For increased reliability of the solder joints, it is
recommended that the pad be soldered to the GND plane.
1
AI = analog input, AI/O = analog input/output, DI = digital input, DO = digital output, and P = power.
B