AT90PWM2B-16SU View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

AT90PWM2B-16SU

8-bit Atmel Microcontroller with 8K Bytes In-System Programmable Flash

Atmel Corporation 

Figure 21-8. Analog Input Circuitry

AT90PWM2/3/2B/3B

ADCn

IIH

IIL

1..100 kΩ

CS/H= 14 pF

VCC/2

21.6.2

Analog Noise Canceling Techniques

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:

1. Keep analog signal paths as short as possible. Make sure analog tracks run over the

analog ground plane, and keep them well away from high-speed switching digital

tracks.

2. The AVCC pin on the device should be connected to the digital VCC supply voltage via

an LC network as shown in Figure 21-9.

3. Use the ADC noise canceler function to reduce induced noise from the CPU.

4. If any ADC port pins are used as digital outputs, it is essential that these do not

switch while a conversion is in progress.

Figure 21-9. ADC Power Connections

1

2

3

4

5

6

7

VCC 8

GND 9

10

11

12

13

14

(ADC0) PE2 15

(ADC1) PD4 16

32 PB7(ADC4)

31 PB6 (ADC7)

30 PB5 (ADC6)

29 PC7 (D2A)

28 PB4 (AMP0+)

27 PB3 (AMP0-)

26 PC6 (ADC10/ACMP1)

25 AREF

24 AGND

23 AVCC

22 PC5 (ADC9/AMP1+)

21 PC4 (ADC8/AMP1-)

20 PB2 (ADC5)

19 PD7 (ACMP0)

18 PD6 (ADC3/ACMPM)

17 PD5 (ADC2/ACMP2)

10μH

100nF

Analog Ground Plane

4317K–AVR–03/2013

242

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