Datasheet

MX7705
16-Bit, Low-Power, 2-Channel,
Sigma-Delta ADC
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Table 4. Peak-to-Peak Resolution vs. Gain and Output Data Rate (V
DD
= 3V)
TYPICAL PEAK-TO-PEAK RESOLUTION (BITS)
GAIN
FILTER FIRST
NOTCH AND
OUTPUT DATA RATE
-3dB FREQUENCY
1 2 4 8 16 32 64 128
BUFFERED (f
CLKIN
= 1MHz)
20Hz 5.24Hz 16 16 16 16 15 14 13 12
25Hz 6.55Hz 16 16 16 16 15 14 13 12
100Hz 26.2Hz 12 12 12 12 12 12 12 11
200Hz 52.4Hz 10 10 10 10 10 10 10 9
UNBUFFERED (f
CLKIN
= 1MHz)
20Hz 5.24Hz 16 16 16 16 15 14 13 12
25Hz 6.55Hz 16 16 16 16 15 14 13 12
100Hz 26.2Hz 12 12 12 12 12 14 12 11
200Hz 52.4Hz 10 10 10 10 10 10 10 9
BUFFERED (f
CLKIN
= 2.4576MHz)
50Hz 13.1Hz 16 16 16 16 15 14 13 12
60Hz 15.72Hz 16 16 16 16 15 14 13 12
250Hz 65.5Hz 12 12 12 12 12 12 11 11
500Hz 131Hz 10 11 10 10 10 10 10 9
UNBUFFERED (f
CLKIN
= 2.4576MHz)
50Hz 13.1Hz 16 16 16 16 15 14 13 12
60Hz 15.72Hz 16 16 16 16 15 14 13 12
250Hz 65.5Hz 12 12 12 12 12 12 11 11
500Hz 131Hz 10 10 10 10 10 10 10 9
TYPICAL OUTPUT NOISE
MX7705 toc01
READING NUMBER
CODE READ
16001200800400
32758
32760
32762
32764
32766
32768
32770
32772
32774
32776
32756
0 2000
V
DD
= 5V,
V
REF
= 2.5V
GAIN = 128
ODR = 60Hz
RMS NOISE = 1.3
μ
V
HISTOGRAM OF TYPICAL OUTPUT NOISE
MX7705 toc02
CODE
OCCURENCE
32773
32772 32771 32770 32769 32768 32767 32766 32765
32764 32763 32762 32761
100
200
300
400
0
32760
V
DD
= 5V, V
REF
= 2.5V
GAIN = 128
ODR = 60Hz
RMS NOISE = 1.3
μ
V
OFFSET ERROR vs. SUPPLY VOLTAGE (3V)
MX7705 toc03
SUPPLY VOLTAGE (V)
OFFSET ERROR (%FSR)
3.453.303.153.002.85
-0.0010
-0.0005
0
0.0005
0.0010
0.0015
-0.0015
2.70 3.60
V
DD
= 3V
Typical Operating Characteristics
(V
DD
= 3V or 5V, V
REF+
= 1.225V for V
DD
= 3V, V
REF+
= 2.5V for V
DD
= 5V, V
REF
- = GND, T
A
= +25°C, unless otherwise noted.)