atmega103 ATMEL Corporation, atmega103 Datasheet - Page 77

• Manufacturer Part Number: atmega103
• Description: Atmega103 8-bit With 128k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Analog-to-Digital
Converter
Feature list:
0945I–AVR–02/07
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The ATmega103(L) features a 10-bit successive approximation ADC. The ADC is con-
nected to an 8-channel Analog Multiplexer, which allows each pin of Port F to be used
as an input for the ADC. The ADC contains a Sample and Hold Amplifier, 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 45.
The ADC has two separate analog supply voltage pins, AV
be connected to GND, and the voltage on AV
V
these pins.
An external reference voltage must be applied to the AREF pin. This voltage must be in
the range AGND - AV
Figure 45. Analog-to-Digital Converter Block Schematic
CC
10-bit Resolution
±2 LSB Absolute Accuracy
0.5 LSB Integral Non-linearity
70 - 280 µs Conversion Time
Up to 14 kSPS
8 Multiplexed Input Channels
Interrupt on ADC Conversion Complete
Sleep Mode Noise Canceler
Reference
. See the section “ADC Noise Canceling Techniques” on page 82 on how to connect
External
Voltage
Analog
Inputs
8-BIT DATA BUS
CHANNEL
MUX
8-
CC
.
+
10-BIT DAC
-
SAMPLE & HOLD
COMPARATOR
ADC MULTIPLEXER
SELECT (ADMUX)
CC
must not differ more than ± 0.3V from
ADC CTRL & STATUS
ADC CONVERSION
REGISTER (ADCSR)
COMPLETE IRQ
ATmega103(L)
CC
CONVERSION LOGIC
and AGND. AGND must
9
ADC DATA REGISTER
(ADCH/ADCL)
0
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