AD7265 Analog Devices, AD7265 Datasheet - Page 12

• Manufacturer Part Number: AD7265
• Description: Differential/Single-Ended Input, Dual 1 MSPS, 12-Bit, 3-Channel SAR A/D Converter
• Manufacturer: Analog Devices

Specifications of AD7265

• Resolution (bits): 12bit
• # Chan: 12
• Sample Rate: 1MSPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni,SE-Uni
• Ain Range: Uni (Vref),Uni (Vref) x 2
• Adc Architecture: SAR
• Pkg Type: CSP,QFP

AD7265
The AD7265 is tested using the CCIF standard where two input
frequencies near the top end of the input bandwidth are used.
In this case, the second-order terms are usually distanced in
frequency from the original sine waves, while the third-order
terms are usually at a frequency close to the input frequencies.
As a result, the second-order and third-order terms are
specified separately. The calculation of the intermodulation
distortion is as per the THD specification, where it is the ratio
of the rms sum of the individual distortion products to the rms
amplitude of the sum of the fundamentals expressed in dBs.
Common-Mode Rejection Ratio (CMRR)
CMRR is defined as the ratio of the power in the ADC output at
full-scale frequency, f, to the power of a 100 mV p-p sine wave
applied to the common-mode voltage of V
frequency f
where:
Pf is the power at frequency f in the ADC output.
f P
Power Supply Rejection Ratio (PSRR)
Variations in power supply affect the full-scale transition but
not the converter’s linearity. PSRR is the maximum change in
the full-scale transition point due to a change in power supply
voltage from the nominal value (see Figure 4).
S
is the power at frequency f
CMRR (dB) = 10 log(Pf/Pf
S
as
S
in the ADC output.
S
)
IN+
and V
IN−
of
Rev. A | Page 12 of 28
Thermal Hysteresis
Thermal hysteresis is defined as the absolute maximum change
of reference output voltage after the device is cycled through
temperature from either
or
It is expressed in ppm by
where:
V
V
T_HYS−.
REF
REF
T_HYS+ = +25°C to T
T_HYS− = +25°C to T
(25°C) is V
(T_HYS) is the maximum change of V
V
HYS
(
ppm
)
REF
=
at 25°C.
V
REF
(
25
MAX
MIN
°
V
) C
REF
to +25°C
to +25°C
−
(
V
25
REF
°
) C
(
T
_
HYS
REF
at T_HYS+ or
)
×
10
6