ATmega16A Atmel Corporation, ATmega16A Datasheet - Page 220

• Manufacturer Part Number: ATmega16A
• Manufacturer: Atmel Corporation

Specifications of ATmega16A

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

220
ATmega16A
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
Table 22-2.
V
V
V
V
ADCn
ADCm
ADCm
ADCm
Figure 22-14
+ 511/512 V
+ 510/512 V
+ V
- V
POS
REF
REF
shows the resulting output codes if the differential input channel pair (ADCn - ADCm)
/GAIN
is the voltage on the positive input pin, V
/GAIN
Correlation between Input Voltage and Output Codes
shows the decoding of the differential input range.
REF
REF
/GAIN
/GAIN
ADC
=
(
----------------------------------------------------------------------- -
V
Output Code
0x3FF
ADC
POS
REF
Read code
0x1FF
0x1FF
0x1FE
0x1FF
0x000
the selected voltage reference. The result is presented
–
=
V
0
NEG
0x200
V
--------------------------
V
IN
REF
V
) GAIN 512
⋅
REF
⋅
1024
NEG
Corresponding Decimal Value
511
511
510
⋅
the voltage on the negative input pin,
REF
.
V
REF
/GAIN Differential Input
Voltage (Volts)
8154B–AVR–07/09