EVAL-AD7793EBZ1 datasheet(22/32 Pages) AD

22 / 32 page

AD7792/AD7793

Rev. B | Page 22 of 32

Single Conversion Mode

In single conversion mode, the AD7792/AD7793 are placed in

shutdown mode between conversions. When a single conver-

sion is initiated by setting MD2, MD1, MD0 to 0, 0, 1 in the

mode register, the AD7792/AD7793 power up, perform a single

conversion, and then return to shutdown mode. The on-chip

oscillator requires 1 ms to power up. A conversion requires a

time period of 2 × tADC. DOUT/RDY goes low to indicate the

completion of a conversion. When the data-word has been read

from the data register, DOUT/RDY goes high. If CS is low,

DOUT/RDY remains high until another conversion is initiated

and completed. The data register can be read several times, if

required, even when DOUT/RDY has gone high.

Continuous Conversion Mode

This is the default power-up mode. The AD7792/AD7793

continuously converts, the RDY pin in the status register going

low each time a conversion is completed. If CS is low, the

DOUT/ RDY line also goes low when a conversion is complete.

To read a conversion, the user writes to the communications

pin as soon as SCLK pulses are applied to the ADC.

DOUT/RDY returns high when the conversion is read. The

user can read this register additional times, if required.

However, the user must ensure that the data register is not being

accessed at the completion of the next conversion, otherwise the

new conversion word is lost.

0x58

DIN

0x08

0x200A

DATA

SCLK

DOUT/RDY

Figure 17. Single Conversion

DIN

SCLK

DOUT/RDY

0x58

DATA

Figure 18. Continuous Conversion

EVAL-AD7793EBZ1 Datasheet(PDF) 22 Page - Analog Devices