MAX1021 Datasheet, PDF (36/40 Pages) Maxim Integrated Products – 10-Bit, Multichannel ADCs/DACs with FIFO, Temperature Sensing, and GPIO Ports

10-Bit, Multichannel ADCs/DACs with FIFO,
Temperature Sensing, and GPIO Ports
t_CH
t_CL
SCLK
1
2
3
4
5
t_DH
t_DS
DIN
D15
D14
t_DOE
DOUT
D15
D7
t_CSS
t_CSPWH
D13
D12
t_DOT
D14
D13
D6
D5
D11
D12
D4
CS
32
16
8
D1
D0
t_DOD
D1
D0
t_CSH
Figure 10. DAC/GPIO Serial-Interface Timing (Clock Modes 00, 01, and 10)
Bipolar ADC Offset Error
While in bipolar mode, the ADC’s ideal midscale transi-
tion occurs at AGND -0.5 LSB. Bipolar offset error is the
measured deviation from this ideal value.
ADC Gain Error
Gain error is defined as the amount of deviation
between the ideal transfer function and the measured
transfer function, with the offset error removed and with
a full-scale analog input voltage applied to the ADC,
resulting in all ones at DOUT.
DAC Offset Error
DAC offset error is determined by loading a code of
all zeros into the DAC and measuring the analog
output voltage.
DAC Gain Error
DAC gain error is defined as the amount of deviation
between the ideal transfer function and the measured
transfer function, with the offset error removed, when
loading a code of all ones into the DAC.
Aperture Jitter
Aperture jitter (t_AJ) is the sample-to-sample variation in
the time between the samples.
Aperture Delay
Aperture delay (t_AD) is the time between the rising
edge of the sampling clock and the instant when an
actual sample is taken.
Signal-to-Noise Ratio
For a waveform perfectly reconstructed from digital sam-
ples, signal-to-noise ratio (SNR) is the ratio of full-scale
analog input (RMS value) to the RMS quantization error
(residual error). The ideal, theoretical minimum analog-
to-digital noise is caused by quantization error only and
results directly from the ADC’s resolution (N bits):
SNR = (6.02 x N + 1.76)dB
In reality, there are other noise sources besides quanti-
zation noise, including thermal noise, reference noise,
clock jitter, etc. Therefore, SNR is calculated by taking
the ratio of the RMS signal to the RMS noise. RMS noise
includes all spectral components to the Nyquist
frequency excluding the fundamental, the first five
harmonics, and the DC offset.
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