AD7895ARZ-10 Analog Devices Inc, AD7895ARZ-10 Datasheet - Page 5

• Manufacturer Part Number: AD7895ARZ-10
• Description: IC,A/D CONVERTER,SINGLE,12-BIT,BICMOS,SOP,8PIN
• Manufacturer: Analog Devices Inc

Specifications of AD7895ARZ-10

• Number Of Bits: 12
• Sampling Rate (per Second): 192k
• Data Interface: Serial
• Number Of Converters: 1
• Power Dissipation (max): 20mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Number Of Elements: 1
• Resolution: 12Bit
• Architecture: SAR
• Sample Rate: 192KSPS
• Input Polarity: Bipolar
• Input Type: Voltage
• Rated Input Volt: ±10V
• Differential Input: No
• Power Supply Requirement: Single
• Single Supply Voltage (typ): 5V
• Single Supply Voltage (min): 4.75V
• Single Supply Voltage (max): 5.25V
• Dual Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Power Dissipation: 20mW
• Differential Linearity Error: ±1LSB
• Integral Nonlinearity Error: ±1LSB
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 8
• Package Type: SOIC N
• Input Signal Type: Single-Ended
• Package: 8SOIC N
• Sampling Rate: 192 KSPS
• Number Of Analog Inputs: 1
• Digital Interface Type: Serial (2-Wire, 3-Wire, SPI)
• Signal To Noise Ratio: 70 dB
• Polarity Of Input Voltage: Bipolar
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TERMINOLOGY
Signal to (Noise + Distortion) Ratio
This is the measured ratio of signal to (noise + distortion) at the
output of the A/D converter. The signal is the rms amplitude of
the fundamental. Noise is the rms sum of all nonfundamental
signals up to half the sampling frequency (f
The ratio is dependent upon the number of quantization levels
in the digitization process; the more levels, the smaller the
quantization noise. The theoretical signal to (noise + distortion)
ratio for an ideal N-bit converter with a sine wave input is given
by:
Thus for a 12-bit converter, this is 74 dB.
Total Harmonic Distortion
Total harmonic distortion (THD) is the ratio of the rms sum of
harmonics to the fundamental. For the AD7895, it is defined as:
where V
V
sixth harmonics.
Peak Harmonic or Spurious Noise
Peak harmonic or spurious noise is defined as the ratio of the
rms value of the next largest component in the ADC output
spectrum (up to f
fundamental. Normally, the value of this specification is
determined by the largest harmonic in the spectrum, but for
parts where the harmonics are buried in the noise floor, it will
be a noise peak.
Intermodulation Distortion
With inputs consisting of sine waves at two frequencies, fa and
fb, any active device with nonlinearities will create distortion
products at sum and difference frequencies of mfa
m, n = 0, 1, 2, 3, etc. Intermodulation terms are those for which
neither m or n are equal to zero. For example, the second order
terms include (fa + fb) and (fa – fb), while the third order terms
include (2 fa + fb), (2 fa – fb), (fa + 2 fb) and (fa – 2 fb).
The AD7895 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 and third order terms are of
different significance. 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 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 fundamental expressed in dBs.
REV. 0
4
, V
5
and V
Signal to (Noise + Distortion) = (6.02 N + 1.76) dB
1
THD (dB) 20 log
is the rms amplitude of the fundamental, and V
6
are the rms amplitudes of the second through the
S
/2 and excluding dc) to the rms value of the
V
2
2
V
3
2
V
V
1
4
S
2
/2), excluding dc.
V
5
2
V
nfb where
6
2
2
, V
3
,
–5–
Relative Accuracy
Relative accuracy or endpoint nonlinearity is the maximum
deviation from a straight line passing through the endpoints of
the ADC transfer function.
Differential Nonlinearity
This is the difference between the measured and the ideal 1 LSB
change between any two adjacent codes in the ADC.
Positive Full-Scale Error (AD7895-10)
This is the deviation of the last code transition (01 . . . 110 to
01 . . . 111) from the ideal (4 VREF – 1 LSB) after the
Bipolar Zero Error has been adjusted out.
Positive Full-Scale Error (AD7895-3)
This is the deviation of the last code transition (01 . . . 110 to
01 . . . 111) from the ideal ( VREF – 1 LSB) after the
Bipolar Zero Error has been adjusted out.
Positive Full-Scale Error (AD7895-2)
This is the deviation of the last code transition (11 . . . 110 to
11 . . . 111) from the ideal (VREF – 1 LSB) after the Unipolar
Offset Error has been adjusted out.
Bipolar Zero Error (AD7895-10, AD7895-3)
This is the deviation of the midscale transition (all 0s to all 1s)
from the ideal 0 V (GND).
Unipolar Offset Error (AD7895-2)
This is the deviation of the first code transition (00 . . . 000 to
00 . . . 001) from the ideal 1 LSB.
Negative Full-Scale Error (AD7895-10)
This is the deviation of the first code transition (10 . . . 000 to
10 . . . 001) from the ideal (–4 VREF + 1 LSB) after Bipolar
Zero Error has been adjusted out.
Negative Full-Scale Error (AD7895-3)
This is the deviation of the first code transition (10 . . . 000 to
10 . . . 001) from the ideal (–VREF + 1 LSB) after Bipolar Zero
Error has been adjusted out.
Track/Hold Acquisition Time
Track/Hold acquisition time is the time required for the output
of the track/hold amplifier to reach its final value, within
track/hold returns to track mode). It also applies to situations
where there is a step input change on the input voltage applied
to the V
wait for the duration of the track/hold acquisition time after the
end of conversion or after a step input change to V
starting another conversion to ensure that the part operates to
specification.
1/2 LSB, after the end of conversion (the point at which the
IN
input of the AD7895. This means that the user must
AD7895
IN
before