AD7478A Analog Devices, AD7478A Datasheet - Page 8

• Manufacturer Part Number: AD7478A
• Description: 8-Bit, 1 MSPS, Low-Power A/D Converter in SC70 and MSOP Packages
• Manufacturer: Analog Devices

Specifications of AD7478A

• Resolution (bits): 8bit
• # Chan: 1
• Sample Rate: 1.2MSPS
• Interface: Ser,SPI
• Analog Input Type: SE-Uni
• Ain Range: Uni Vdd
• Adc Architecture: SAR
• Pkg Type: SC70,SOP

AD7476A/AD7477A/AD7478A
TIMING SPECIFICATIONS
V
Table 4.
Parameter
f
t
t
t
t
t
t
t
t
t
t
t
1
2
3
4
5
6
7
SCLK
CONVERT
QUIET
1
2
3
4
5
6
7
8
POWER-UP
Guaranteed by characterization. All input signals are specified with tr = tf = 5 ns (10% to 90% of V
Mark/space ratio for the SCLK input is 40/60 to 60/40.
Minimum f
Measured with the load circuit shown in Figure 2, and defined as the time required for the output to cross 0.8 V or 1.8 V when V
0.8 V or 2.0 V for V
Measured with a 50 pF load capacitor.
t
extrapolated back to remove the effects of charging or discharging the 50 pF capacitor. Therefore, the time, t
relinquish time of the part and is independent of the bus loading.
See the Power-Up Time section.
4
4
5
6
DD
8
is derived from the measured time taken by the data outputs to change 0.5 V when loaded with the circuit shown in Figure 2. The measured number is then
2
= 2.35 V to 5.25 V; T
7
SCLK
at which specifications are guaranteed.
Limit at T
10
20
20
16 × t
14 × t
12 × t
50
10
10
22
40
0.4 t
0.4 t
10
9.5
7
36
t
1
DD
7
values also apply to t
> 2.35 V.
SCLK
SCLK
SCLK
SCLK
SCLK
A
MIN
= T
, T
MAX
MIN
to T
MAX
8
minimum values
, unless otherwise noted.
Rev. F | Page 8 of 28
Unit
kHz min
kHz min
MHz max
ns min
ns min
ns min
ns max
ns max
ns min
ns min
ns min
ns min
ns min
ns max
ns min
μs max
1
3
3
Description
A, B grades
Y grade
AD7476A
AD7477A
AD7478A
Minimum quiet time required between bus relinquish
and start of next conversion
Minimum CS pulse width
CS to SCLK setup time
Delay from CS until SDATA three-state disabled
Data access time after SCLK falling edge
SCLK low pulse width
SCLK high pulse width
SCLK to data valid hold time
V
3.3 V < V
V
SCLK falling edge to SDATA high impedance
SCLK falling edge to SDATA high impedance
Power-up time from full power-down
DD
DD
DD
≤ 3.3 V
> 3.6 V
) and timed from a voltage level of 1.6 V.
DD
≤ 3.6 V
8
, quoted in the timing characteristics is the true bus
DD
= 2.35 V, and