Texas Instruments ADS9110EVM-PDK, Руководство пользователя, Страница: 18 / 37

ADS9110EVM-PDK Operation
www.ti.com
Figure 12. Time Domain Display Tool Options
6.4 Spectral Analysis Tool
The spectral analysis tool is intended to evaluate the dynamic performance (SNR, THD, SFDR, SINAD,
and ENOB) of the ADS9110 SAR ADC through single-tone sinusoidal signal FFT analysis using the 7-
term Blackman-Harris window setting. Also, the window setting of "None" can be used to look for noise
spurs over frequency in DC inputs.
For dynamic performance evaluation, the external differential source must have better specifications than
the ADC itself to ensure that the measured system performance is not limited by the performance of the
signal source. Therefore, it is critical that the external reference source meets the source requirements
mentioned in
Table 4 .
Table 4. External Source Requirements for ADS9110 Evaluation
Specification Description Specification Value
Signal Frequency 2 kHz
External Source Type Balanced Differential
0 V or Floating
External Source Common Mode
(Refer to Section 2.2.2 for jumper settings)
External Source Impedance (R
S
) 10
Ω
–30
Ω
External Source Differential Impedance
20 Ω –60 Ω
(R
S_DIFF
= 2 × R
S
)
(2 × R
S
× 4.45 × 10
–3
) + 8.9 V
Source Differential Signal
or
(V
PP
Amplitude for –0.1 dBFS)
(R
S_DIFF
× 4.45 × 10
–3
) + 8.9 V
Maximum Noise 10 µV
RMS
Maximum SNR 110 dB
Maximum THD –130 dB
18 ADS9110EVM-PDK SBAU249 – October 2015
Submit Documentation Feedback
Copyright © 2015, Texas Instruments Incorporated