EVX10AS150ATP ETC-unknow, EVX10AS150ATP Datasheet - Page 53

• Manufacturer Part Number: EVX10AS150ATP
• Description: Adc Single 2.5gsps 10-bit Lvds 317-pin Ebga
• Manufacturer: ETC-unknow

5.2.2
e2v semiconductors SAS 2009
Differential Versus Single-ended Input Dynamic Performance (SNR, SFDR, THD)
Since the ADC tolerates up to 12 degrees of phase unbalance without impacting the dynamic perfor-
mance (SFDR), it is not mandatory to use cascaded (double) transformer to improve phase balance
characteristics. Double transformer implementations may degrade the inherent band flatness of the
device with additional insertion loss.
Figure 5-6.
The EV10AS150A implements a front-end Track and Hold preamplifier which has been designed in
order to be entered either in differential or single-ended, up to maximum operating sampling rate without
significant loss in dynamic performance in either 1
Scale:
Same SNR values are measured in single-ended and differential, 1
0.2 dB).
Regarding linearity performance (Total Harmonic Distortion (THD) and Spurious Free Dynamic Range
(SFDR)):
• If differential driven, it is the odd Harmonics (mainly H3) which mainly dictates the ADC large signal
• In single-ended driven, the even harmonics (H2, H4, …) will become significant with the same
linearity performance (SFDR and THD), whereas the even harmonics (H2, H4, …) only little
contributes to THD.
weighting as the odd Harmonics (H3,H5,…). The 2
Harmonic, mainly in the 2
The EV10AS150A front-end preamplifier has been boosted to maintain the 2
below –60 dBFS in single-ended over 1
Scale. Since the 2
performance will not be impacted.
VINN (DC = +3V)
Full Scale input power:
0.5 Vpp into 50 = -2 dBm
+ 250 mVp
ADC Full Scale Single Ended vs. Differential Analog Input
Vin = 500 mVpp
ADC Full Scale
Single ended
nd
harmonic weighting is not higher than the 3
-
nd
Nyquist.
st
and 2
+ 500 mVpp
nd
st
Nyquist, even for large signals close to ADC Full
and 2
nd
Harmonic will rise to the same level as 3
nd
+125 mV
Nyquist for large signals close to ADC Full
Full Scale input power:
0.5 Vpp into 100 = -5 dBm
rd
+ 250 mV
Harmonic level (H3), the SFDR
st
Vin = 500 mVpp
ADC Full Scale
Differential
and 2
VIN
nd
nd
EV10AS150A
Nyquist (delta SNR <
Harmonic (H2) level
0954B–BDC–12/09
- 250 mV
VINN
rd
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