ATmega165 datasheet(198/336 Pages) ATMEL

Part #	ATmega165

Description	8-bit Microcontroller with 16K Bytes In-System Programmable Flash

PDF	336 Pages

Scroll/Zoom	100%

Manufacturer	ATMEL [ATMEL Corporation]

Direct Link	http://www.atmel.com

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198 / 336 page

198

ATmega165/V

2573G–AVR–07/09

ADC Accuracy Definitions

An n-bit single-ended ADC converts a voltage linearly between GND and V

REF in 2

steps (LSBs). The lowest code is read as 0, and the highest code is read as 2

n-1.

Several parameters describe the deviation from the ideal behavior:

•

Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal

transition (at 0.5 LSB). Ideal value: 0 LSB.

Figure 92. Offset Error

•

Gain Error: After adjusting for offset, the Gain Error is found as the deviation of the

last transition (0x3FE to 0x3FF) compared to the ideal transition (at 1.5 LSB below

maximum). Ideal value: 0 LSB

Figure 93. Gain Error

•

Integral Non-linearity (INL): After adjusting for offset and gain error, the INL is the

maximum deviation of an actual transition compared to an ideal transition for any

code. Ideal value: 0 LSB.

Output Code

VREF Input Voltage

Ideal ADC

Actual ADC

Offset

Error

Output Code

VREF Input Voltage

Ideal ADC

Actual ADC

Gain

Error

ATmega165 Datasheet(PDF) 198 Page - ATMEL Corporation