MCP3901EV-MCU16 Microchip Technology, MCP3901EV-MCU16 Datasheet - Page 23

• Manufacturer Part Number: MCP3901EV-MCU16
• Description: BOARD EVAL FOR 2CH ADC MCP3901
• Manufacturer: Microchip Technology

Specifications of MCP3901EV-MCU16

• Number Of Adc's: 2
• Number Of Bits: 24
• Data Interface: SPI™
• Inputs Per Adc: 1 Differential
• Input Range: ±1 V
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: MCP3901
• Silicon Manufacturer: Microchip
• Application Sub Type: ADC
• Kit Application Type: Data Converter
• Silicon Core Number: MCP3901, PIC24F, PIC24H, DsPIC33, PIC18F86J55
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.6
© 2009 Microchip Technology Inc.
FFT WINDOW - FREQUENCY DOMAIN ANALYSIS
EQUATION 3-1:
This equation changes to Equation 3-2 if the data is represented on 24 bits:
EQUATION 3-2:
ENOB can be computed also when an AC signal is applied at the input. The formula to
compute ENOB in an AC case is the following:
EQUATION 3-3:
The distribution of noise from the acquired signal can be seen on the Histogram Graph
screens.These graphs indicate how many times a code was present inside a buffer.
The spectrum of the acquired signal is visible in the Signal Spectrum screen. Above
these graphics there is a button that can be used to set the Y axis to be linear or
logarithmic. A logarithmic scale on the Y axis is useful to see the level of low harmonics,
or the noise floor. The length of the FFT is given by the buffer length and the sampling
speed. The X axis is scaled directly in Hz units.
Another feature of the software is the window selection for the FFT computation. This
is done from the “Window” fields, in the lower region of the GUI, right above the
Current FFT screens. The user can select from a large number of windows.
Since the GUI performs the spectral analysis of the acquired signal, it is possible to
compute AC performance parameters of the ADC: “THD” and “SINAD” are shown on
the indicators, under the Histogram Graph screens.
ENOB
ENOB
ENOB
=
=
=
SINAD 1.76
----------------------------------
16 log
24 log
–
–
6.02
–
2
2
( )
( )
MCP3901 PC Software Tool
σ
σ
DS51845A-page 19