ADC1206S040 Datasheet, PDF (27/32 Pages) NXP Semiconductors – Single 12 bits ADC, up to 40 MHz, 55 MHz or 70 MHz

NXP Semiconductors
ADC1206S040/055/070
Single 12 bits ADC, up to 40 MHz, 55 MHz or 70 MHz
13.2.3 Total Harmonic Distortion (THD)
The ratio of the power of the harmonics to the power of the fundamental. For k-1
harmonics the THD is: THD[dB]
=
10log
P_{----h---a---r--m----o---n---i-c---s}
P_signal
where
P_harmonics
=
α
2
2
+
α
2
3
+
α
2
k
P_signal
=
α
2
1
The value of k is usually 6 (i.e. calculation of THD is done on the first 5 harmonics).
13.2.4 Signal-to-Noise ratio (S/N)
The ratio of the output signal power to the noise power, excluding the harmonics and the
DC component. S/N[dB] = 10log ^P-_P---^s-_n--ⁱ-_og---_in--_s-^a-_e-^l
13.2.5 Spurious Free Dynamic Range (SFDR)
The number SFDR specifies available signal range as the spectral distance between the
amplitude of the fundamental and the amplitude of the largest spurious (harmonic and
non-harmonic, excluding DC component). SFDR[dB] = 20log _m-----_a--^α--_x--¹-₍--_s---₎
13.3 Intermodulation distortion
13.3.1 Spectral analysis (dual-tone)
0
(dB)
−40
IMD3
014aaa384
−80
−120
−160
0
5
10
15
20
25
30
measured output range (HHz)
Fig 27. Spectral analysis (dual-tone)
ADC1206S040_055_070_2
Product data sheet
From a dual-tone input sinusoid (f_t 1 and f_t 2, these frequencies being chosen according to
the coherence criterion), the intermodulation distortion products IMD2 and IMD3
(respectively, 2nd and 3rd order components) are defined, as follows.
Rev. 02 — 12 August 2008
© NXP B.V. 2008. All rights reserved.
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