ATTINY85-15ST1 Atmel, ATTINY85-15ST1 Datasheet - Page 119

• Manufacturer Part Number: ATTINY85-15ST1
• Description: MCU AVR 8K FLASH 15MHZ 8-SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY85-15ST1

• Package / Case: 8-SOIC (3.9mm Width)
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 105°C
• Speed: 16MHz
• Number Of I /o: 6
• Eeprom Size: 512 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Program Memory Size: 8KB (8K x 8)
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

18.6.2
18.6.3
7598H–AVR–07/09
Analog Noise Canceling Techniques
ADC Accuracy Definitions
Figure 18-8. 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:
An n-bit single-ended ADC converts a voltage linearly between GND and V
(LSBs). The lowest code is read as 0, and the highest code is read as 2
Several parameters describe the deviation from the ideal behavior:
Figure 18-9. Offset Error
• Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal transition
(at 0.5 LSB). Ideal value: 0 LSB.
a. Keep analog signal paths as short as possible. Make sure analog tracks run over
b. Use the ADC noise canceler function to reduce induced noise from the CPU.
c. If any port pins are used as digital outputs, it is essential that these do not switch
the analog ground plane, and keep them well away from high-speed switching digi-
tal tracks.
while a conversion is in progress.
ADCn
Output Code
Offset
Error
I
IH
I
IL
1..100 kohm
V
REF
Input Voltage
C
ATtiny25/45/85
S/H
= 14 pF
Ideal ADC
Actual ADC
n
-1.
V
CC
REF
/2
in 2
n
steps
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