adc0808s125 NXP Semiconductors, adc0808s125 Datasheet - Page 15

• Manufacturer Part Number: adc0808s125
• Description: Single 8-bit Adc, Up To 125 Mhz Or 250 Mhz
• Manufacturer: NXP Semiconductors

NXP Semiconductors
ADC0808S125_ADC0808S250_2
Product data sheet
12.2.4 Signal-to-Noise ratio (S/N)
12.2.5 Spurious Free Dynamic Range (SFDR)
12.2.6 InterModulation Distortion (IMD)
The value of k is usually 6 (THD is calculated based on the first 5 harmonics).
S/N is the ratio of the output signal power to the noise power, excluding the harmonics and
the DC component:
The SFDR value specifies the available signal range as the spectral distance between the
amplitude of the fundamental (a
non-harmonic (max (s)), excluding the DC component:
The second-order and third-order intermodulation distortion products IMD2 and IMD3 are
defined using a dual tone input sinusoid, where f
coherence criterion.
IMD is the ratio of the RMS value of either tone to the RMS value of the worst, second or
third-order intermodulation products.
The total intermodulation distortion is given by:
P
SFDR dB
S N
P
Fig 11. Spectrum of dual tone input sine wave of frequencies f
signal
harmonics
=
=
10log
a
2
1
=
=
f
10
a
1
20log
2
2
+
f
P
--------------- -
P
2
signal
a
2f
noise
2
3
2
10
+
f
f
Rev. 02 — 7 October 2008
1
2
----------------- -
max s
a
+
2f
f
1
1
1
a
2
k
f
2
1
) and the amplitude of the largest spurious harmonic and
2f
f
1
2
+ f
2f
2
1
f
1
+ 2f
Single 8-bit ADC, up to 125 MHz or 250 MHz
3f
2
2
2f
3f
1
1
1
+ f
and f
ADC0808S125/250
2
2
are chosen according to the
1
and f
frequency
2
© NXP B.V. 2008. All rights reserved.
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