ADUC814 Analog Devices, ADUC814 Datasheet - Page 15

• Manufacturer Part Number: ADUC814
• Description: Precision Analog Microcontroller: 1.3MIPS 8052 MCU + 8kB Flash + 6-Ch 12-Bit ADC + Dual 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC814

• Mcu Core: 8052
• Mcu Speed (mips): 1.3
• Sram (bytes): 256Bytes
• Gpio Pins: 17
• Adc # Channels: 6

Figure 13 and Figure 14 show typical FFT plots for the ADuC814.
These plots were generated using an external clock input via
P3.5 to achieve coherent sampling. The ADC is using its internal
reference (2.5 V) sampling a full-scale, 10 kHz sine wave test
tone input at a sampling rate of 149.79 kHz. The resultant FFTs
shown at 5 V and 3 V supplies illustrate an excellent 100 dB
noise floor, a 71 dB signal-to-noise ratio (SNR), and a THD
greater than −80 dB.
–100
–120
–140
–160
–100
–120
–140
–160
–20
–40
–60
–80
–20
–40
–60
–80
20
20
0
0
Figure 13. ADuC814 Dynamic Performance at V
Figure 14. ADuC814 Dynamic Performance at V
0
0
10
10
20
20
FREQUENCY (kHz)
FREQUENCY (kHz)
30
30
40
40
50
50
AV
f
f
SNR = 71.3dB
THD = –88.0dB
ENOB = 11.6
AV
f
f
SNR = 71.3dB
THD = –88.0dB
ENOB = 11.6
S
IN
S
IN
= 149.79kHz
= 149.79kHz
DD
= 9.910kHz
DD
= 9.910kHz
/DV
/DV
60
60
DD
DD
DD
DD
= 5 V
= 3 V
= 5V
= 3V
70
70
Rev. A | Page 15 of 72
Figure 15 and Figure 16 show typical dynamic performance
versus external reference voltages. Again excellent ac performance
can be observed in both plots with some roll-off being observed
as V
REF
80
75
70
65
60
55
50
80
75
70
65
60
55
50
falls below 1 V.
Figure 15. Typical Dynamic Performance vs. V
Figure 16. Typical Dynamic Performance vs. V
0.5
0.5
1.0
1.0
EXTERNAL REFERENCE (V)
EXTERNAL REFERENCE (V)
1.5
1.5
2.0
2.0
2.5
AV
f
2.5
S
AV
f
S
= 152kHz
DD
DD
= 152kHz
/DV
/DV
REF
REF
3.0
SNR
DD
THD
SNR
DD
5.0
, V
, V
THD
= 5V
DD
= 3V
DD
ADuC814
= 5 V
= 3 V
–70
–75
–80
–85
–90
–95
–100
–70
–80
–85
–75
–100
–90
–95