ATMEGA32A-AN Atmel, ATMEGA32A-AN Datasheet - Page 222

• Manufacturer Part Number: ATMEGA32A-AN
• Description: IC MCU AVR 32K FLASH 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32A-AN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

22.8
8155C–AVR–02/11
ADC Conversion Result
After the conversion is complete (ADIF is high), the conversion result can be found in the ADC
Result Registers (ADCL, ADCH).
For single ended conversion, the result is
where V
Table 22-3 on page 222
0x3FF represents the selected reference voltage minus one LSB.
If differential channels are used, the result is
where V
GAIN the selected gain factor, and V
in two’s complement form, from 0x200 (-512d) through 0x1FF (+511d). Note that if the user
wants to perform a quick polarity check of the results, it is sufficient to read the MSB of the result
(ADC9 in ADCH). If this bit is one, the result is negative, and if this bit is zero, the result is posi-
tive.
Table 22-2
is selected with a gain of GAIN and a reference voltage of V
Figure 22-14. Differential Measurement Range
Figure 22-14
- V
IN
POS
REF
is the voltage on the selected input pin and V
shows the resulting output codes if the differential input channel pair (ADCn - ADCm)
/GAIN
is the voltage on the positive input pin, V
shows the decoding of the differential input range.
and
ADC
Table 22-4 on page
=
(
----------------------------------------------------------------------- -
V
Output Code
0x3FF
ADC
POS
REF
0x1FF
0x000
the selected voltage reference. The result is presented
–
=
V
0
0x200
NEG
V
--------------------------
V
IN
REF
V
) GAIN 512
⋅
REF
⋅
1024
223). 0x000 represents analog ground, and
NEG
REF
⋅
the voltage on the negative input pin,
REF
the selected voltage reference (see
.
V
REF
ATmega32A
/GAIN Differential Input
Voltage (Volts)
222