Datasheet

AD7190 Data Sheet
Rev. C | Page 10 of 40
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
NC = NO CONNECT
1
2
3
4
5
6
7
8
9
10
12
11
MCLK2
SCLK
CS
P1/REFIN2(+)
P2
P3
MCLK1
P0/REFIN2(–)
NC
AINCOM
AIN2
AIN1
20
21
22
23
24
19
18
17
16
15
14
13
DOUT/RDY
SYNC
DV
DD
AGND
DGND
AV
DD
BPDSW
REFIN1(–)
AIN3
AIN4
REFIN1(+)
DIN
AD7190
TOP VIEW
(Not to Scale)
07640-005
Figure 5. Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Description
1 MCLK1 When the master clock for the device is provided externally by a crystal, the crystal is connected between
MCLK1 and MCLK2.
2
MCLK2
Master Clock Signal for the Device. The AD7190 has an internal 4.92 MHz clock. This internal clock can be
made available on the MCLK2 pin. The clock for the AD7190 can be provided externally also in the form of
a crystal or external clock. A crystal can be tied across the MCLK1 and MCLK2 pins. Alternatively, the
MCLK2 pin can be driven with a CMOS-compatible clock and the MCLK1 pin left unconnected.
3 SCLK Serial Clock Input. This serial clock input is for data transfers to and from the ADC. The SCLK has a Schmitt-
triggered input, making the interface suitable for opto-isolated applications. The serial clock can be
continuous with all data transmitted in a continuous train of pulses. Alternatively, it can be a noncon-
tinuous clock with the information transmitted to or from the ADC in smaller batches of data.
4
CS
Chip Select Input. This is an active low logic input used to select the ADC.
CS
can be used to select the ADC
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 ADC to operate in 3-wire mode
with SCLK, DIN, and DOUT used to interface with the device.
5 P3 Digital Output Pin. This pin can function as a general-purpose output bit referenced between AV
DD
and AGND.
6 P2 Digital Output Pin. This pin can function as a general-purpose output bit referenced between AV
DD
and AGND.
7 P1/REFIN2(+) Digital Output Pin/Positive Reference Input. This pin functions as a general-purpose output bit referenced
between AV
DD
and AGND. When REFSEL = 1, this pin functions as REFIN2(+). An external reference can be
applied between REFIN2(+) and REFIN2(−). REFIN2(+) can lie anywhere between AV
DD
and AGND + 1 V. The
nominal reference voltage, (REFIN2(+) − REFIN2(−)), is AV
DD
, but the part functions with a reference from
1 V to AV
DD
.
8 P0/REFIN2(−) Digital Output Pin/Negative Reference Input. This pin functions as a general-purpose output bit referenced
between AV
DD
and AGND. When REFSEL = 1, this pin functions as REFIN2(−). This reference input can lie
anywhere between AGND and AV
DD
− 1 V.
9 NC No Connect. This pin should be tied to AGND.
10 AINCOM Analog Input AIN1 to Analog Input AIN4 are referenced to this input when configured for pseudo
differential operation.
11 AIN1 Analog Input. It can be configured as the positive input of a fully differential input pair when used with
AIN2 or as a pseudo differential input when used with AINCOM.
12 AIN2 Analog Input. It can be configured as the negative input of a fully differential input pair when used with
AIN1 or as a pseudo differential input when used with AINCOM.