AD7794/AD7795
Pin No. Mnemonic
Description
18
AIN4(−)/REFIN2(−) Analog Input/Negative Reference Input. AIN4(−) is the negative terminal of the differential analog input pair
AIN4(+)/AIN4(−). This pin also functions as the negative reference input for REFIN2. This reference input can
lie anywhere between GND and AVDD − 0.1 V.
19
20
21
22
PSW
GND
AVDD
DVDD
Low-Side Power Switch to GND.
Ground Reference Point.
Supply Voltage, 2.7 V to 5.25 V.
Serial Interface Supply Voltage, 2.7 V to 5.25 V. DVDD is independent of AVDD. Therefore, the serial interface
operates at 3 V with AVDD at 5 V or vice versa.
23
24
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 also 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.
DIN
Serial Data Input to the Input Shift Register on the ADC. Data in this shift register is transferred to the control
registers within the ADC with the register selection bits of the communications register identifying the
appropriate register.
Rev. D | Page 12 of 36
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