Datasheet

© 2012 Microchip Technology Inc. DS22286A-page 13
MCP3911
Note: Unless otherwise indicated, AVDD = 3.3V, DVDD = 3.3V; TA = 25 °C, MCLK = 4 MHz; PRESCALE = 1; OSR
= 256; GAIN = 1; Dithering = Maximum; VIN = -0.5 dBFS @ 60 Hz, VREFEXT = 0; CLKEXT = 1, AZ_FREQ
= 0; BOOST = 1X.
FIGURE 2-13: SINAD vs. OSR.
L
FIGURE 2-14: SNR vs.OSR.
FIGURE 2-15: SFDR vs. OSR.
FIGURE 2-16: THD vs. MCLK.
FIGURE 2-17: SINAD vs. MCLK.
FIGURE 2-18: SNR vs. MCLK.
40
50
60
70
80
90
100
110
120
o
-Noise and Distortion
Ratio (dB)
Dithering = Maximum
Dithering = Medium
Dithering = Minimum
Dithering = None
0
10
20
30
40
32 64 128 256 512 1024 2048 4096
Signal-t
o
Oversampling Ratio (OSR)
40
50
60
70
80
90
100
110
120
-
to-Noise Ratio (dB)
Dithering = Maximum
Dithering = Medium
Dithering = Minimum
Dithering = None
0
10
20
30
40
32 64 128 256 512 1024 2048 4096
Signal
-
Oversampling Ratio (OSR)
50
60
70
80
90
100
110
120
130
140
r
ee Dynamic Range
(dBFS)
Dithering = Maximum
Dithering = Medium
Dithering = Minimum
Dithering = None
0
10
20
30
40
32 64 128 256 512 1024 2048 4096
Spurious F
r
Oversampling Ratio (OSR)
-
90
-80
-70
-60
-50
-40
-30
-20
-10
0
rmonic Distortion (dBc)
Boost = 0.5x
Boost = 0.66x
Boost = 1x
-120
-110
-100
90
0 5 10 15 20 25 30
Total Ha
MCLK Frequency (MHz)
Boost = 2x
40
50
60
70
80
90
100
110
120
-
Noise and Distortion
Ratio (dB)
Boost
=05x
Boost = 0.66x
Boost = 2x
Boost = 1x
0
10
20
30
40
0 5 10 15 20 25 30
Signal-to
-
MCLK Frequency (MHz)
Boost
=0
.
5x
40
50
60
70
80
90
100
110
120
al to Noise Ratio (dB)
Boost = 0.5x
Boost = 0.66x
Boost = 2x
Boost = 1x
0
10
20
30
0 5 10 15 20 25 30
Sign
MCLK Frequency (MHz)