ADC0808S250 NXP Semiconductors, ADC0808S250 Datasheet - Page 14

• Manufacturer Part Number: ADC0808S250
• Description: (ADC0808S125 / ADC0808S250) Single 8-bit ADC
• Manufacturer: NXP Semiconductors

NXP Semiconductors
ADC0808S125_ADC0808S250_3
Product data sheet
12.2.1 Signal-to-Noise And Distortion (SINAD)
12.2.2 Effective Number Of Bits (ENOB)
12.2.3 Total Harmonic Distortion (THD)
Remark: P
which include random noise, non-linearities, sampling time errors, and quantization noise.
SINAD is the ratio of the output signal power to the noise plus distortion power for a given
sample rate and input frequency, excluding the DC component:
ENOB is derived from SINAD and gives the theoretical resolution required by an ideal
ADC to obtain the same SINAD measured on the real ADC. A good approximation gives:
THD is the ratio of the power of the harmonics to the power of the fundamental. For k
harmonics the THD is:
where:
SINAD dB
ENOB
THD dB
Fig 10. Single tone spectrum of full-scale input sine wave of frequency f
=
a = harmonic.
s = single tone.
SINAD 1.76
----------------------------------
=
noise
=
10log
6.02
10log
in the equations in the following sections, is the sum of noise sources
–
10
10
a
Rev. 03 — 24 February 2009
P
------------------------ -
1
harmonics
P
--------------------------------------- -
P
signal
noise
P
signal
+
distortion
a
2
Single 8-bit ADC, up to 125 MHz or 250 MHz
a
3
s
ADC0808S125/250
SFDR
a
frequency
k
© NXP B.V. 2009. All rights reserved.
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