AD7927BRUZ Analog Devices Inc, AD7927BRUZ Datasheet - Page 7

• Manufacturer Part Number: AD7927BRUZ
• Description: IC ADC 12BIT 8CH 200KSPS 20TSSOP
• Manufacturer: Analog Devices Inc

Specifications of AD7927BRUZ

• Data Interface: DSP, MICROWIRE™, QSPI™, Serial, SPI™
• Number Of Bits: 12
• Sampling Rate (per Second): 200k
• Number Of Converters: 1
• Power Dissipation (max): 7.5mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP (0.173", 4.40mm Width)
• Resolution (bits): 12bit
• Sampling Rate: 200kSPS
• Input Channel Type: Single Ended
• Supply Voltage Range - Analog: 2.7V To 5.25V
• Supply Current: 1.5mA
• Number Of Elements: 1
• Resolution: 12Bit
• Architecture: SAR
• Sample Rate: 200KSPS
• Input Polarity: Unipolar
• Input Type: Voltage
• Rated Input Volt: 2.5/5V
• Differential Input: No
• Power Supply Requirement: Analog and Digital
• Single Supply Voltage (typ): 3/5V
• Single Supply Voltage (min): 2.7V
• 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: 7.5mW
• Differential Linearity Error: -0.9LSB/1.5LSB
• Integral Nonlinearity Error: ±1LSB
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 20
• Package Type: TSSOP
• Input Signal Type: Single-Ended
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-AD7927CBZ - BOARD EVALUATION FOR AD7927
• Lead Free Status / Rohs Status: Compliant

TERMINOLOGY
Integral Nonlinearity
This is the maximum deviation from a straight line passing
through the endpoints of the ADC transfer function. The end-
points of the transfer function are zero-scale, a point 1 LSB
below the first code transition, and full-scale, a point 1 LSB
above the last code transition.
Differential Nonlinearity
This is the difference between the measured and the ideal 1 LSB
change between any two adjacent codes in the ADC.
Offset Error
This is the deviation of the first code transition (00 . . . 000) to
(00 . . . 001) from the ideal, i.e., AGND + 1 LSB.
Offset Error Match
This is the difference in offset error between any two channels.
Gain Error
This is the deviation of the last code transition (111 . . . 110) to
(111 . . . 111) from the ideal (i.e., REF
offset error has been adjusted out.
Gain Error Match
This is the difference in gain error between any two channels.
Zero Code Error
This applies when using the twos complement output coding
option, in particular to the 2 ¥ REF
to +REF
the midscale transition (all 0s to all 1s) from the ideal V
age, i.e., REF
Zero Code Error Match
This is the difference in Zero Code Error between any two
channels.
Positive Gain Error
This applies when using the twos complement output coding
option, in particular to the 2 ¥ REF
to +REF
the last code transition (011. . .110) to (011 . . . 111) from the
ideal (i.e., +REF
adjusted out.
Positive Gain Error Match
This is the difference in Positive Gain Error between any two
channels.
Negative Gain Error
This applies when using the twos complement output coding
option, in particular to the 2 ¥ REF
to +REF
the first code transition (100 . . . 000) to (100 . . . 001) from the
ideal (i.e., –REF
been adjusted out.
REV. 0
IN
IN
IN
biased about the REF
biased about the REF
biased about the REF
IN
– 1 LSB.
IN
IN
– 1 LSB) after the Zero Code Error has been
+ 1 LSB) after the Zero Code Error has
IN
IN
IN
point. It is the deviation of
point. It is the deviation of
point. It is the deviation of
IN
IN
IN
input range with –REF
input range with –REF
input range with –REF
IN
– 1 LSB) after the
IN
volt-
IN
IN
IN
–7–
Negative Gain Error Match
This is the difference in Negative Gain Error between any two
channels.
Channel-to-Channel Isolation
Channel-to-Channel Isolation is a measure of the level of crosstalk
between channels. It is measured by applying a full-scale 400 kHz
sine wave signal to all seven nonselected input channels and deter-
mining how much that signal is attenuated in the selected channel
with a 50 kHz signal. The figure is given worst case across all
eight channels for the AD7927.
PSR (Power Supply Rejection)
Variations in power supply will affect the full-scale transition,
but not the converter’s linearity. Power supply rejection is the
maximum change in full-scale transition point due to a change
in power supply voltage from the nominal value. See Typical
Performance Characteristics.
Track-and-Hold Acquisition Time
The track-and-hold amplifier returns into track mode at the
end of conversion. Track-and-hold acquisition time is the time
required for the output of the track-and-hold amplifier to reach
its final value, within ± 1 LSB, after the end of conversion.
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 sum of all nonfundamental signals
up to half the sampling frequency (f
is dependent on the number of quantization levels in the digiti-
zation 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 AD7927, it is defined as:
where V
V
sixth harmonics.
4
, V
5
, and V
Signal to Noise Distortion
1
THD dB
is the rms amplitude of the fundamental and V
- - (
6
(
are the rms amplitudes of the second through the
)
=
20
+
log
V
2
2
+
) ( .
V
S
/2), excluding dc. The ratio
=
3
2
+
6 02
V
V
1
4
2
N
+
V
+
AD7927
5
2
1 76
+
.
V
6
)
2
dB
2
, V
3
,