MAX1068ACEG+T Maxim Integrated, MAX1068ACEG+T Datasheet - Page 27

• Manufacturer Part Number: MAX1068ACEG+T
• Description: Analog to Digital Converters - ADC MultiCh 14-Bit 200ksps
• Manufacturer: Maxim Integrated

Specifications of MAX1068ACEG+T

• Rohs: yes
• Number Of Channels: 8
• Architecture: SAR
• Conversion Rate: 200 KSPs
• Resolution: 14 bit
• Input Type: Single-Ended
• Snr: 84 dB
• Interface Type: QSPI, Serial (SPI, Microwire)
• Operating Supply Voltage: 2.7 V to 5.25 V, 4.75 V to 5.25 V
• Maximum Operating Temperature: + 70 C
• Package / Case: QSOP-24
• Maximum Power Dissipation: 762 mW
• Minimum Operating Temperature: 0 C
• Number Of Converters: 1
• Voltage Reference: 4.096 V

Figure 23. DSP Interface Connection
Integral nonlinearity (INL) 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 linearity parameters for the MAX1067/MAX1068
are measured using the end-point method.
Differential nonlinearity (DNL) is the difference between
an actual step-width and the ideal value of ±1 LSB. A
DNL error specification of ±1 LSB guarantees no miss-
ing codes and a monotonic transfer function.
Aperture jitter (t
the time between samples. Aperture delay (t
time between the falling edge of the sampling clock
and the instant when the actual sample is taken.
For a waveform perfectly reconstructed from digital
samples, signal-to-noise ratio (SNR) is the ratio of the
full-scale analog input (RMS value) to the RMS quanti-
zation error (residual error). The ideal, theoretical mini-
mum analog-to-digital noise is caused by quantization
Multichannel, 14-Bit, 200ksps Analog-to-Digital
DSP
AJ
SCLK
RFS
TFS
FL1
DR
DT
) is the sample-to-sample variation in
______________________________________________________________________________________
EXTERNAL
CLOCK
Differential Nonlinearity
Signal-to-Noise Ratio
Integral Nonlinearity
Aperture Definitions
SCLK
DSPR
DSPX
DIN
DOUT
CS
Definitions
MAX1068
AD
) is the
noise error only and results directly from the ADC’s res-
olution (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, which includes all spectral
components minus the fundamental, the first five har-
monics, and the DC offset.
Signal-to-noise plus distortion (SINAD) is the ratio of the
fundamental input frequency’s RMS amplitude to the
RMS equivalent of all the other ADC output signals:
Effective number of bits (ENOB) indicates the global
accuracy of an ADC at a specific input frequency and
sampling rate. An ideal ADC’s error consists of quanti-
zation noise only. With an input range equal to the full-
scale range of the ADC, calculate the ENOB as follows:
Figure 24 shows the ENOB as a function of the MAX1067/
MAX1068s’ input frequency.
Figure 24. Effective Bits vs. Frequency
SINAD (dB) = 20
16
14
12
10
8
6
4
2
0
ENOB = (SINAD - 1.76) / 6.02
0.1
SNR = (6.02
EFFECTIVE NUMBER OF BITS (ENOB)
Signal-to-Noise Plus Distortion
f
SAMPLE
Distortion)
= 200ksps
✕
Effective Number of Bits
FREQUENCY (kHz)
1
log [Signal
✕
Converters
N + 1.76)dB
RMS
10
]
RMS
/ (Noise +
100
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