AD7789 Analog Devices, AD7789 Datasheet - Page 6

• Manufacturer Part Number: AD7789
• Description: 24-Bit, Single-Channel, Ultra Low Power, Sigma Delta A/D Converter
• Manufacturer: Analog Devices

Specifications of AD7789

• Resolution (bits): 24bit
• # Chan: 1
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni
• Ain Range: (2Vref) p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: SOP

AD7788/AD7789
TIMING CHARACTERISTICS
V
Input Logic 0 = 0 V; Input Logic 1 = V
Table 4.
Parameter
t
t
Read Operation
Write Operation
1
2
3
4
5
6
3
4
Sample tested during initial release to ensure compliance. All input signals are specified with t
See Figure 3 and Figure 4.
These numbers are measured with the load circuit of, and defined as, the time required for the output to cross the V
SCLK active edge is the falling edge of SCLK.
These numbers are derived from the measured time taken by the data output to change 0.5 V when loaded with the circuit of Figure 2. The measured number is then
extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. This means that the times quoted in the Timing Characteristics are the true
bus relinquish times of the part and, as such, are independent of external bus loading capacitances.
RDY returns high after a read of the ADC. In single-conversion mode and continuous-conversion mode, the same data can be read again, if required, while RDY is high,
although care should be taken to ensure that subsequent reads do not occur close to the next output update. In continuous read mode, the digital word can be read
only once.
DD
t
t
t
t
t
t
t
t
t
1
2
5
6
7
8
9
10
11
3
5, 6
= 2.5 V to 5.25 V (AD7788B and AD7789); V
1, 2
Limit at T
100
100
0
60
80
0
60
80
10
80
0
10
0
30
25
0
MIN
, T
MAX
DD
, unless otherwise noted.
(B Version)
DD
= 2.7 V to 5.25 V (AD7788A); GND = 0 V; REFIN(+) = 2.5 V; REFIN(−) = GND;
Rev. B | Page 6 of 20
Unit
ns min
ns min
ns min
ns max
ns max
ns min
ns max
ns max
ns min
ns max
ns min
ns min
ns min
ns min
ns min
ns min
Description
SCLK high pulse width
SCLK low pulse width
CS falling edge to DOUT/RDY active time
V
V
SCLK active edge to data valid delay
V
V
Bus relinquish time after CS inactive edge
SCLK inactive edge to CS inactive edge
SCLK inactive edge to DOUT/RDY high
CS falling edge to SCLK active edge setup time
Data valid to SCLK edge setup time
Data valid to SCLK edge hold time
CS rising edge to SCLK edge hold time
R
DD
DD
DD
DD
= t
= 4.75 V to 5.25 V
= 2.7 V to 3.6 V
= 4.75 V to 5.25 V
= 2.7 V to 3.6 V
F
= 5 ns (10% to 90% of V
OL
or V
OH
DD
limits.
) and timed from a voltage level of 1.6 V.
4
4