TDA8768A Datasheet, PDF (26/32 Pages) NXP Semiconductors – 12-bit, 70 Msps Analog-to-Digital Converter (ADC)

Philips Semiconductors
TDA8768A
12-bit, 70 Msps Analog-to-Digital Converter (ADC)
The total intermodulation distortion IMD is given by
IMD[dB]
=
10log
P_{----i--n---t--e--r--m----o---d-}
P_signal
where,
P_intermod
=
a
2
im
(
f
t1
–
f
t2⁾
–
a
2
im
(
f
t1
+
f _t2) + a _i2m( f _t1 – 2 f _t2)
+a
2
im
(
f
t
1
+
2 f _t2)
+a
i2m^{(2 f t1}
–
f _t2) +
a
2
im
(
2
f
t
1
+
f _t2)
P_signal = a²( f _t1) + a²( f _t2)
and
a _i2m( f _t)
is the power in the intermodulation component at frequency f_t.
12.1.4 Noise Power Ratio (NPR)
When using a notch-filtered broadband white-noise generator as the input to the ADC
under test, the Noise Power Ratio is defined as the ratio of the average out-of-notch
to the in-notch power spectral density magnitudes for the FFT spectrum of the ADC
output sample set.
9397 750 09656
Product data
Rev. 02 — 03 July 2002
© Koninklijke Philips Electronics N.V. 2002. All rights reserved.
26 of 32