Datasheet

Data Sheet AD7190
Rev. C | Page 11 of 40
Pin No. Mnemonic Description
13 AIN3 Analog Input. It can be configured as the positive input of a fully differential input pair when used with
AIN4 or as a pseudo differential input when used with AINCOM.
14 AIN4 Analog Input. It can be configured as the negative input of a fully differential input pair when used with
AIN3 or as a pseudo differential input when used with AINCOM.
15
REFIN1(+)
Positive Reference Input. An external reference can be applied between REFIN1(+) and REFIN1(−).
REFIN1(+) can lie anywhere between AV
DD
and AGND + 1 V. The nominal reference voltage, (REFIN1(+) −
REFIN1(−)), is AV
DD
, but the part functions with a reference from 1 V to AV
DD
.
16 REFIN1(−) Negative Reference Input. This reference input can lie anywhere between AGND and AV
DD
− 1 V.
17 BPDSW Bridge Power-Down Switch to AGND.
18 AGND Analog Ground Reference Point.
19
DGND
Digital Ground Reference Point.
20 AV
DD
Analog Supply Voltage, 4.75 V to 5.25 V. AV
DD
is independent of DV
DD
.
21 DV
DD
Digital Supply Voltage, 2.7 V to 5.25 V. DV
DD
is independent of AV
DD
.
22
SYNC
Logic input that allows for synchronization of the digital filters and analog modulators when using
multiple AD7190 devices. While
SYNC
is low, the nodes of the digital filter, the filter control logic, and the
calibration control logic are reset and the analog modulator is held in its reset state.
SYNC
does not affect
the digital interface but does reset
RDY
to a high state if it is low.
SYNC
has a pull-up resistor internally to
DV
DD
.
23 DOUT/
RDY
Serial Data Output/Data Ready Output. DOUT/
RDY
serves a dual purpose. It functions as a serial data
output pin to access the output shift register of the ADC. The output shift register can contain data from
any of the on-chip data or control registers. In addition, DOUT/
RDY
operates as a data ready pin, going low
to indicate the completion of a conversion. If the data is not read after the conversion, the pin goes high
before the next update occurs. The DOUT/
RDY
falling edge can be used as an interrupt to a processor,
indicating that valid data is available. With an external serial clock, the data can be read using the
DOUT/
RDY
pin. With
CS
low, the data/control word information is placed on the DOUT/
RDY
pin on
the SCLK falling edge and is valid on the SCLK rising edge.
24 DIN Serial Data Input to the Input Shift Register on the ADC. Data in this shift register is transferred to the
control registers in the ADC, with the register selection bits of the communications register identifying the
appropriate register.