MAX1191ETI+ Maxim Integrated Products, MAX1191ETI+ Datasheet - Page 24

• Manufacturer Part Number: MAX1191ETI+
• Description: IC ADC 8BIT 7.5MSPS DUAL 28-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1191ETI+

• Number Of Bits: 8
• Sampling Rate (per Second): 7.5M
• Data Interface: Parallel
• Number Of Converters: 2
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-WFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Ultra-Low-Power, 7.5Msps, Dual 8-Bit ADC
Figure 13. T/H Aperture Timing
Integral nonlinearity is the deviation of the values on an
actual transfer function from a straight line. This straight
line can be either a best-straight-line fit or a line drawn
between the end points of the transfer function, once
offset and gain errors have been nullified. The static lin-
earity parameters for the MAX1191 are measured using
the end-point method.
Differential nonlinearity is the difference between an
actual step width and the ideal value of 1LSB. A DNL
error specification of less than 1LSB guarantees no
missing codes and a monotonic transfer function.
Ideally, the midscale MAX1191 transition occurs at 0.5
LSB above midscale. The offset error is the amount of
deviation between the measured transition point and
the ideal transition point.
Ideally, the full-scale MAX1191 transition occurs at 1.5
LSB below full-scale. The gain error is the amount of
deviation between the measured transition point and
the ideal transition point with the offset error removed.
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DATA (T/H)
SAMPLED
Static Parameter Definitions
ANALOG
INPUT
CLK
T/H
t
AD
Differential Nonlinearity (DNL)
TRACK
Integral Nonlinearity (INL)
t
HOLD
AJ
Offset Error
TRACK
Gain Error
Figure 13 depicts the aperture jitter (t
sample-to-sample variation in the aperture delay.
Aperture delay (t
rising edge of the sampling clock and the instant when
an actual sample is taken (Figure 13).
For a waveform perfectly reconstructed from digital
samples, the theoretical maximum SNR is the ratio of
the full-scale analog input (RMS value) to the RMS
quantization error (residual error). The ideal, theoretical
minimum analog-to-digital noise is caused by quantiza-
tion error only and results directly from the ADC’s reso-
lution (N bits):
In reality, there are other noise sources besides quanti-
zation noise: thermal noise, reference noise, clock jitter,
etc. SNR is computed by taking the ratio of the RMS
signal to the RMS noise. RMS noise includes all spec-
tral components to the Nyquist frequency excluding the
fundamental, the first five harmonics, and the DC offset.
SINAD is computed by taking the ratio of the RMS sig-
nal to the RMS noise. RMS noise includes all spectral
components to the Nyquist frequency excluding the
the fundamental and the DC offset.
ENOB specifies the dynamic performance of an ADC at
a specific input frequency and sampling rate. An ideal
ADC’s error consists of quantization noise only. ENOB
for a full-scale sinusoidal input waveform is computed
from:
Signal-to-Noise Plus Distortion (SINAD)
Dynamic Parameter Definitions
SNR
Effective Number of Bits (ENOB)
ENOB
dB[max]
AD
Signal-to-Noise Ratio (SNR)
) is the time defined between the
=
= 6.02 × N + 1.76
SINAD
6 02
.
- 1 76
Aperture Delay
Aperture Jitter
.
AJ
), which is the