AT90PWM216-16SE ATMEL [ATMEL Corporation], AT90PWM216-16SE Datasheet - Page 244

• Manufacturer Part Number: AT90PWM216-16SE
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable flash
• Manufacturer: ATMEL [ATMEL Corporation]

21.6.2
244
AT90PWM216/316
Analog Noise Canceling Techniques
Figure 21-8. Analog Input Circuitry
Digital circuitry inside and outside the device generates EMI which might affect the accuracy of
analog measurements. If conversion accuracy is critical, the noise level can be reduced by
applying the following techniques:
Figure 21-9. ADC Power Connections
a. Keep analog signal paths as short as possible. Make sure analog tracks run over
b. The AV
c. Use the ADC noise canceler function to reduce induced noise from the CPU.
d. If any ADC port pins are used as digital outputs, it is essential that these do not
the analog ground plane, and keep them well away from high-speed switching digi-
tal tracks.
via an LC network as shown in
switch while a conversion is in progress.
CC
(ADC1) PD4
(ADC0) PE2
pin on the device should be connected to the digital V
GND
VCC
ADCn
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
I
IH
Figure
I
IL
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
21-9.
Analog Ground Plane
1..100 kΩ
PB7(ADC4)
PB6 (ADC7)
PB5 (ADC6)
PC7 (D2A)
PB4 (AMP0+)
PB3 (AMP0-)
PC6 (ADC10/ACMP1)
AREF
AGND
AVCC
PC5 (ADC9/AMP1+)
PC4 (ADC8/AMP1-)
PB2 (ADC5)
PD7 (ACMP0)
PD6 (ADC3/ACMPM)
PD5 (ADC2/ACMP2)
C
S/H
= 14 pF
V
CC
CC
/2
supply voltage
100nF
7710D–AVR–08/09