ATMEGA8_08 Datasheet, PDF (196/308 Pages) ATMEL Corporation – 8-bit with 8K Bytes In-System Programmable Flash

Analog-to-
Digital
Converter
Features
• 10-bit Resolution
• 0.5 LSB Integral Non-linearity
• ± 2 LSB Absolute Accuracy
• 13 - 260 µs Conversion Time
• Up to 15 kSPS at Maximum Resolution
• 6 Multiplexed Single Ended Input Channels
• 2 Additional Multiplexed Single Ended Input Channels (TQFP and QFN/MLF Package only)
• Optional Left Adjustment for ADC Result Readout
• 0 - V_CC ADC Input Voltage Range
• Selectable 2.56V ADC Reference Voltage
• Free Running or Single Conversion Mode
• Interrupt on ADC Conversion Complete
• Sleep Mode Noise Canceler
The ATmega8 features a 10-bit successive approximation ADC. The ADC is connected to an 8-
channel Analog Multiplexer which allows eight single-ended voltage inputs constructed from the
pins of Port C. The single-ended voltage inputs refer to 0V (GND).
The ADC contains a Sample and Hold circuit which ensures that the input voltage to the ADC is
held at a constant level during conversion. A block diagram of the ADC is shown in Figure 90.
The ADC has a separate analog supply voltage pin, AV_CC. AV_CC must not differ more than ±
0.3V from V_CC. See the paragraph “ADC Noise Canceler” on page 201 on how to connect this
pin.
Internal reference voltages of nominally 2.56V or AV_CC are provided On-chip. The voltage refer-
ence may be externally decoupled at the AREF pin by a capacitor for better noise performance.
196 ATmega8(L)
2486T–AVR–05/08