Dynamic Performance Metric Calculation Methodology - Xilinx AMS101 User Manual

X-Ref Target - Figure A-2
DACOUTB
2
BNCINA
J2
1
2 R15
1
49.9
HDR_1X2 1/10W
2
1%
XADC_AGND
DACOUTA
2
BNCINB
J6
1
2
R19
1
HDR_1X2
49.9
1/10W
2
1%
XADC_AGND

Dynamic Performance Metric Calculation Methodology

SNR is calculated by removing the DC, the fundamental, and the first five harmonics
components from the FFT data. All the remaining components are root sum squared
together. This number is divided by the fundamental component and converted into
decibels (dB).
THD is a measure of the ratio of the root sum square of the first seven harmonics to the
fundamental, also expressed in dB.
SINAD is similar to the SNR calculation except it does not throw out the first five
harmonics.
SFDR is a measure of the difference between the magnitude of the largest spur and the
magnitude of the fundamental in dB.
ENOB is calculated directly from the SINAD number.
AMS101 Evaluation Card User Guide
UG886 (v1.3) November 6, 2013
J3
1
2
BNCINA_R 3
HDR_1X3
C12
1
1000PF
2 50V
X7R
XADC_AGND
J5
1
2
BNCINB_R 3
HDR_1X3
C16
1
1000PF
2 50V
X7R
XADC_AGND
Figure A-2: AMS101 Evaluation Card Schematic (2 of 2)
www.xilinx.com
Dynamic Performance Metric Calculation Methodology
XADC_VCC5V0
KEYED_RECEPT_2X10_SMT
VADJ
SSW-110-22-G-D-VS-N
XADC_VP
XADC_VN
NC
XADC_VREF
2
XADC_GPIO_1
2
XADC_GPIO_3
2
XADC_AGND
1 2 XADC_VP
3 4
5 6 XADC_VN
7 8
9 10
11 12 NC
13 14 NC
15 16
17 18 XADC_GPIO_0
19 20 XADC_GPIO_2
J1
1
2
XADC_AGND GND
UG886_aA_02_062512
3
3
2
2
49