ATtiny461 Automotive Atmel Corporation, ATtiny461 Automotive Datasheet - Page 152

• Manufacturer Part Number: ATtiny461 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATtiny461 Automotive

• Flash (kbytes): 4 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 256
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

19.7.2
19.7.3
152
ATtiny261/ATtiny461/ATtiny861
Analog Noise Canceling Techniques
ADC Accuracy Definitions
Digital circuitry inside and outside the device generates EMI which might affect the accuracy of
analog measurements. If conversion accuracy is critical, the noise level can be reduced by
applying the following techniques:
An n-bit single-ended ADC converts a voltage linearly between GND and V
(LSBs). The lowest code is read as 0, and the highest code is read as 2
Several parameters describe the deviation from the ideal behavior:
• Offset: The deviation of the first transition (0x000 to 0x001) compared to the ideal transition (at
Figure 19-9. Offset Error
• Gain Error: After adjusting for offset, the Gain Error is found as the deviation of the last
0.5 LSB). Ideal value: 0 LSB.
transition (0x3FE to 0x3FF) compared to the ideal transition (at 1.5 LSB below maximum).
Ideal value: 0 LSB
a. Keep analog signal paths as short as possible. Make sure analog tracks run over the
b. Use the ADC noise canceler function to reduce induced noise from the CPU.
c. If any port pins are used as digital outputs, it is essential that these do not switch
analog ground plane, and keep them well away from high-speed switching digital
tracks.
while a conversion is in progress.
Output Code
Offset
Error
V
REF
Input Voltage
Ideal ADC
Actual ADC
n
-1.
REF
7753F–AVR–01/11
in 2
n
steps