ADC的各项参数定义：
Parameter Definitions
Integral Nonlinearity (INL)
Integral nonlinearity is the deviation of the values on an
actual transfer function from a straight line. For the
MAX1209, this straight line is between the end points of
the transfer function, once offt and gain errors have
been nullified. INL deviations are measured at every
step of the transfer function and the worst-ca deviation
is reported in the Electrical Characteristics table.
Differential Nonlinearity (DNL)
Differential nonlinearity is the difference between an
actual step width and the ideal value of 1 LSB. A DNL无线网络技术
母鸡头error specification of less than 1 LSB guarantees no
missing codes and a monotonic transfer function. For
福字the MAX1209, DNL deviations are measured at every
step of the transfer function and the worst-ca deviation
is reported in the Electrical Characteristics table.
Offt Error
Offt error is a figure of merit that indicates how well
the actual transfer function matches the ideal transfer
function at a single point. Ideally the midscale
MAX1209 transition occurs at 0.5 LSB above midscale.
The offt error is the amount of deviation between the
measured midscale transition point and the ideal midscale
transition point.
Gain Error
Gain error is a figure of merit that indicates how well the
slope of the actual transfer function matches the slope
of the ideal transfer function. The slope of the actual
transfer function is measured between two data points:
positive full scale and negative full scale. Ideally, the
positive full-scale MAX1209 transition occurs at 1.5
LSBs below positive full scale, and the negative fullscale
transition occurs at 0.5 LSB above negative full
scale. The gain error is the difference of the measured
transition points minus the difference of the ideal transition
points.
Small-Signal Noi Floor (SSNF)
Small-signal noi floor is the integrated noi and distortion
power in the Nyquist band for small-signal最后的的英语
inputs. The DC offt is excluded from this noi calculation.
单反拍For this converter, a small signal is defined as a小心滑倒
single tone with an amplitude less than -35dBFS. This
parameter captures the thermal and quantization noi
characteristics of the converter and can be ud to
help calculate the overall noi figure of a receive
channel. Go to for application
notes on thermal + quantization noi floor.
Signal-to-Noi Ratio (SNR)
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 noi is caud by quantization
error only and results directly from the ADC’s resolution
(N bits):
SNR[max] = 6.02 × N + 1.76
In reality, there are other noi sources besides quantization
noi: thermal noi, reference noi, clock jitter,etc.
SNR is computed by taking the ratio of the RMS志愿填报模拟
signal to the RMS noi. RMS noi includes all spectral
components to the Nyquist frequency excluding the
fundamental, the first six harmonics (HD2–HD7), and
the DC offt.
Signal-to-Noi Plus Distortion (SINAD)
SINAD is computed by taking the ratio of the RMS signal
to the RMS noi plus distortion. RMS noi plus distortion
includes all spectral components to the Nyquist frequency
excluding the fundamental and the DC offt.
Effective Number of Bits (ENOB)
ENOB specifies the dynamic performance of an ADC at
a specific input frequency and sampling rate. An ideal
ADC’s error consists of quantization noi only. ENOB for
a full-scale sinusoidal input waveform. is computed from:
（SINAD - 1.76）/ 6.02
Single-Tone Spurious-Free Dynamic Range
(SFDR)
SFDR is the ratio expresd in decibels of the RMS
amplitude of the fundamental (maximum signal component)
to the RMS amplitude of the next-largest spurious
component, excluding DC offt.
什么运动鞋好Total Harmonic Distortion (THD)
THD is the ratio of the RMS sum of the first six harmonics
of the input signal to the fundamental itlf. This is
expresd as:
where V1 is the fundamental amplitude, and V2 through
V7 are the amplitudes of the 2nd- through 7th-order
