ADUC847 Analog Devices, ADUC847 Datasheet - Page 31

• Manufacturer Part Number: ADUC847
• Description: Precision Analog Microcontroller: 12MIPS 8052 Flash MCU + 10-Ch 24-Bit ADC + 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC847

• Mcu Core: 8052
• Mcu Speed (mips): 12
• Sram (bytes): 2304Bytes
• Gpio Pins: 34
• Adc # Channels: 10
• Other: PWM

ADC Noise Performance with Chop Disabl
Table 14, Table 15, Table 16, and Table 17 show the output rm
noise and output peak-to-peak reso
the neares
num
volt
upda
regi
the r
li
The output noise comes from two sources. The first source is
the electrical noise in the semicond
used in th
Tab
SF Word
3
13
68
82
255
Ta
SF Word
3
13
68
82
255
Table 16.
SF Word
3
13
69
82
255
Table 17. ADuC848 Typical Peak-to-Peak Resolution (Bits
SF Word
3
13
68
82
255
mit.
ble 15. AD
age of 0 V and a common-mode voltage of
ster. Note th
le 14. ADu
esolution fo
bers are ty
te rate is s
e imp
AD
t 0.5
Data Update
Rate (Hz)
1365.33
315.08
59.36
49.95
16.06
Da
Ra
1365.33
315.08
59.36
49.95
16.06
Data U
Rate (Hz)
1365.33
315.08
59.36
49.95
16.06
Data Up
Rate (
1365.33
315.08
59.36
49.95
16.06
uC845 a
uC848 Typical Output R
pical and
elected
C845 a
LSB) for some typical out
lementation of the modu
te (Hz
at the p
r whi
ta Upd
Hz)
pdate
ch there is no code flicker
date
)
nd ADuC847 Typical O
nd ADuC847 Typical P
via the SF7 to SF0 bits in
ate
eak-to-peak resolution
are generated at a diff
±20 mV
7.5
11.5
13
13
13.5
±20 mV
30.64
2.07
0.85
0.83
0.52
±20 mV
7.5
11.5
13
13
13.5
±20 mV
30.64
2.07
0.85
0.83
0.52
uctor devices (device noise)
lution in bits (rounded to
MS No
put up
lator.
ed (CHOP
The s
erentia
eak-to-Pe
ise (µV)
±40 mV
9
12.5
14
14
14.5
within
figure
utp
±40 m
24.5
1.95
0.79
0.77
0.58
±40 m
9
12.5
14
14
14.5
±40
24.5
1.95
0.79
0.77
0.58
date
2.5 V.
the S
ut RMS Noise (µV) vs
mV
econd
rates. The
F filter
s represent
The output
l input
V
V
a 6-sigma
= 1)
vs. Input Range a
ak Resolution (B
±80 mV
9
13.5
14.5
15
15.5
±80 mV
56.18
2.28
1.01
0.85
0.59
±80 mV
9
13.5
14.5
15
15.5
±80 mV
56.18
2.28
1.01
0.85
0.59
Rev. B | Page 31 of 108
) vs. Input R
s
±160 mV
9
14
15.5
16
16
±
1
3.24
0.99
0.77
0.48
±
9
1
15.5
16
16.5
±
1
3.24
0.99
0.77
0.48
. Input Range and Update Rate with Chop Disabled
00.47
4
00.47
160 mV
160 mV
160 mV
nd Update Rate with Chop Disabled
ange and Update Rate with Chop Disabled
source is quantization noise, which is added when the analog
input is converted to the digital domain. The device noise is at a
low level and is independent of frequency. The quantization
noise starts at an even lower level but rises rapidly with increasi
frequency to become the dominant noise source.
The numbers in the tables are given for the bipolar input ranges.
For the unipolar ranges, the rms noise numbers are the same as
the bipolar range, but the peak-to
half the signal range, which effectively means losing 1 bit of
resolution. Typically, the performance of the ADC with chop
disabled shows a 0.5 LSB degradation over the performance
with chop enabled.
its) vs. Input Range and Update Rate with Chop Disabled
Input Range
Input Range
Input Range
Input Range
±320mV
9
13.5
16
16
16
±320 mV
248.39
8.22
0.79
0.91
0.52
±320 mV
9
13.5
17
16.5
17.5
±320 mV
248.39
8.22
0.79
0.91
0.52
ADuC845/ADuC847/ADuC848
±640mV
14
16
16
9
16
±64
468.65
13.9
1.29
1.12
0.57
±640 mV
9
14
17
17.5
18.5
±640 mV
468.65
13.9
1.29
1.12
0.57
0 mV
-peak resolution is based on
±1.28 V
9
14
16
16
16
±1.28 V
774.36
20.98
2.3
1.59
1.16
±1.28 V
9
14
17.5
18
18.5
±1.28 V
774.36
20.98
2.3
1.59
1.16
±2.56 V
1739.5
49.26
3.7
3.2
1.68
±2.56 V
9
14
18
18
19
±2.56 V
1739.5
49.26
3.7
3.2
1.68
±2.56 V
9
14
16
16
16
ng