Datasheet

Maxim Integrated │ 31
MAX11166/MAX11167 16-Bit, 500ksps/250ksps, ±5V SAR ADCs
with Internal Reference in TDFN
www.maximintegrated.com
Effective Number of Bits
The 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 quantiza-
tion noise only. With an input range equal to the full-scale
range of the ADC, calculate the ENOB as follows:
SINAD 1.76
ENOB
6.02
−
=
Total Harmonic Distortion
Total harmonic distortion (THD) is the ratio of the RMS
sum of the first five harmonics of the input signal to the
fundamental itself. This is expressed as:

+++

= ×



2222
2345
2
1
VVVV
THD 10 log
V
where V
1
is the fundamental amplitude and V
2
through V
5
are the 2nd- through 5th-order harmonics.
Spurious-Free Dynamic Range
Spurious-free dynamic range (SFDR) is the ratio of the
RMS amplitude of the fundamental (maximum signal
component) to the RMS value of the next-largest fre-
quency component.
Aperture Delay
Aperture delay (t
AD
) is the time delay from the sampling
clock edge to the instant when an actual sample is taken.
Aperture Jitter
Aperture jitter (t
AJ
) is the sample-to-sample variation in
aperture delay.
Small-Signal Bandwidth
A small -20dBFS analog input signal is applied to an ADC
in a manner that ensures that the signal’s slew rate does
not limit the ADC’s performance. The input frequency is
then swept up to the point where the amplitude of the
digitized conversion result has decreased 3dB.
Full-Power Bandwidth
A large -0.5dBFS analog input signal is applied to an
ADC, and the input frequency is swept up to the point
where the amplitude of the digitized conversion result
has decreased by 3dB. This point is defined as full-power
input bandwidth frequency.