AD7787 datasheet(17/21 Pages) AD

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AD7787

Data Sheet

Rev. A | Page 16 of 20

Single Conversion Mode

In single conversion mode, the AD7787 is placed in shutdown

mode between conversions. When a single conversion is

initiated by setting MD1 to 1 and MD0 to 0 in the mode

and then returns to shutdown mode. When a single conversion

is initiated, the AD7787’s oscillator requires 1 ms to power up

and settle. The AD7787 then performs a conversion which

requires 2 × tADC. DOUT/RDY is high while the conversion is

being performed and goes low to indicate the completion of the

conversion. When the data word has been read from the data

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 AD7787 will

continuously converts with the RDY pin in the status register

going low each time a conversion is complete. If CS is low, the

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

To read a conversion, the user can write 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 or the new

conversion word is lost.

DIN

SCLK

DOUT/RDY

0x38

DATA

Figure 14. Continuous Conversion

AD7787 Datasheet(PDF) 17 Page - Analog Devices