AC164120 Microchip Technology, AC164120 Datasheet - Page 23

• Manufacturer Part Number: AC164120
• Description: BOARD SIGNAL ANALYSIS PICKIT
• Manufacturer: Microchip Technology
• Series: PICtail™r

Specifications of AC164120

• Main Purpose: Interface, Signal Analysis
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: PICkit™ PICtail™1
• Primary Attributes: Real-time Strip Chart, Oscilloscope, Fast Fourier Transformation (FFT)
• Secondary Attributes: Histogram
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC16
• Features: Real-Time Strip Chart, Fast Fourier Transformation
• Silicon Core Number: PIC16F
• Silicon Family Name: PIC16F6xxx
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: PICkit Flash Starter Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Using the PICkit™ 1 Signal Analysis PC Application
Rectangular – Window is a rectangular shaped window. Every point of the time scale
is multiplied by a constant. This window provides the best frequency resolution with the
narrowest lobe width. Amplitude accuracy errors occur if frequency of observed signal
has a non-integer number of cycles in the FFT time record. Most typically, this window
is best used when viewing transients, impulses, pseudo-random noise and when the
input signal is correlated with the sampling frequency.
When the FFT windows are implemented there is a certain amount of energy that is
spread across adjacent frequency bins. This spreading is a result of converting
non-coherent signals and the particular window. Consequently, there is not a direct
correlation between the amplitude of the analog input signal to the A/D converter and
the height of the spur in the FFT analysis.
2.6.1
Glossary of Terms
Fundamental Frequency – The lowest frequency component in the Fourier
representation of a periodic quantity.
Noise Floor – The noise level at a referenced location and bandwidth.
SNR (Signal-to-Noise Ratio) – The ratio of relative power of the usable signal to the
noise present, expressed in decibels.
SINAD (Signal to (Noise + Distortion) Ratio) – S/(N+D) is the ratio of the rms value
of the actual input signal to the rms sum of all other spectral components or harmonics
below the Nyquist frequency, excluding DC. This software includes nine harmonics in
the calculation. Decibels is the unit of measure for S/(N+D).
THD (Total Harmonic Distortion) – The ratio in dB of the energy of a fundamental test
frequency to the energy of its harmonics appearing in the band of interest.
SFDR (Spurious Free Dynamic Range) – The difference in decibels between the
input signal and the next largest harmonic.
 2004 Microchip Technology Inc.
DS51476A-page 19