AD7707 Analog Devices, AD7707 Datasheet - Page 37

• Manufacturer Part Number: AD7707
• Manufacturer: Analog Devices

Specifications of AD7707

• Resolution (bits): 16bit
• # Chan: 3
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni,SE-Bip
• Ain Range: Bip (Vref)/(PGA Gain),Bip 10V,Bip 5.0V,Uni (Vref)/(PGA Gain),Uni 10V,Uni 5.0V
• Adc Architecture: Sigma-Delta
• Pkg Type: SOIC,SOP

CONFIGURING THE AD7707
The AD7707 contains six on-chip registers that the user can
accesses via the serial interface. Communication with any of
these registers is initiated by writing to the communications
register first. Figure 22 outlines a flow diagram of the sequence
used to configure all registers after a power-up or reset on the
AD7707. The flowchart also shows two different read options—
the first in which the DRDY pin is polled to determine when an
SCLK
DRDY
SCLK
DOUT
DIN
CS
CS
t
3
t
5
t
t
11
4
t
12
MSB
MSB
t
13
Figure 21. Write Cycle Timing Diagram
Figure 20. Read Cycle Timing Diagram
t
t
6
14
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t
t
15
7
update of the data register has taken place, the second in which
the DRDY bit of the communications register is interrogated to
determine if a data register update has taken place. Also included
in the flowing diagram is a series of words that should be writ-
ten to the registers for a particular set of operating conditions.
These conditions are gain of 1, no filter sync, bipolar mode,
buffer off, clock of 4.9512 MHz, and an output rate of 50 Hz.
LSB
LSB
t
10
t
t
8
9
t
16
AD7707