at90pwm81-16se ATMEL Corporation, at90pwm81-16se Datasheet - Page 212

• Manufacturer Part Number: at90pwm81-16se
• Description: 8-bit Avr Microcontroller With 8k Bytes In- System Programmable Flash
• Manufacturer: ATMEL Corporation

18.6.4
212
AT90PWM81
ADC Accuracy Definitions
differential inputs using the AMPxIS bit with both inputs unconnected.
Status register – AMP0CSR” on page
the measurement results. Using this kind of software based offset correction, offset on any channel can be
reduced below one LSB.
An n-bit single-ended ADC converts a voltage linearly between GND and V
lowest code is read as 0, and the highest code is read as 2
Several parameters describe the deviation from the ideal behavior:
Figure 18-10. Offset Error
• Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal transition (at 0.5
• Gain Error: After adjusting for offset, the Gain Error is found as the deviation of the last transition
LSB). Ideal value: 0 LSB.
(0x3FE to 0x3FF) compared to the ideal transition (at 1.5 LSB below maximum). Ideal value: 0 LSB
Output Code
Offset
Error
224.). This offset residue can be then subtracted in software from
n
-1.
V
REF
(See “Amplifier 0 Control and
REF
Input Voltage
in 2
n
Ideal ADC
Actual ADC
steps (LSBs). The
7734M–AVR–03/10