ATTINY861-15MZ Atmel, ATTINY861-15MZ Datasheet - Page 153

• Manufacturer Part Number: ATTINY861-15MZ
• Description: MCU AVR 8K FLASH 15MHZ 32-QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY861-15MZ

• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 16
• Eeprom Size: 512 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Program Memory Size: 8KB (8K x 8)
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Processor Series: ATTINY8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: SPI
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATAVRMC320
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 11 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

19.8.3
19.9
2588B–AVR–11/06
Temperature Measurement
Bipolar Differential Conversion
155). The voltage on the positive pin must always be larger than the voltage on the negative pin
or otherwise the voltage difference is saturated to zero. The result is presented in one-sided
form, from 0x000 (0d) to 0x3FF (+1023d). The GAIN is either 1x, 8x, 20x or 32x.
As default the ADC converter operates in the unipolar input mode, but the bipolar input mode
can be selected by writting the BIN bit in the ADCSRB to one. In the bipolar input mode two-
sided voltage differences are allowed and thus the voltage on the negative input pin can also be
larger than the voltage on the positive input pin. If differential channels and a bipolar input mode
are used, the result is
where V
and V
0x200 (-512d) through 0x000 (+0d) to 0x1FF (+511d). The GAIN is either 1x, 8x, 20x or 32x.
However, if the signal is not bipolar by nature (9 bits + sign as the 10th bit), this scheme loses
one bit of the converter dynamic range. Then, if the user wants to perform the conversion with
the maximum dynamic range, the user can perform a quick polarity check of the result and use
the unipolar differential conversion with selectable differential input pair. When the polarity check
is performed, it is sufficient to read the MSB of the result (ADC9 in ADCH). If the bit is one, the
result is negative, and if this bit is zero, the result is positive.
The temperature measurement is based on an on-chip temperature sensor that is coupled to a
single ended ADC11 channel. Selecting the ADC11 channel by writing the MUX5..0 bits in
ADMUX register to “111111” enables the temperature sensor. The internal 1.1V voltage refer-
ence must also be selected for the ADC voltage reference source in the temperature sensor
measurement. When the temperature sensor is enabled, the ADC converter can be used in sin-
gle conversion mode to measure the voltage over the temperature sensor.
The measured voltage has a linear relationship to the temperature as described in
page
measurement is +/-
Table 19-2.
The values described in
variation the temperature sensor output voltage varies from one chip to another. To be capable
of achieving more accurate results the temperature measurement can be calibrated in the appli-
cation software. The software calibration requires that a calibration value is measured and
stored in a register or EEPROM for each chip. The sofware calibration can be done utilizing the
formula:
Temperature / °C
153. The voltage sensitivity is approximately 1 mV/
REF
Voltage / mV
POS
the selected voltage reference. The result is presented in two’s complement form, from
is the voltage on the positive input pin, V
Temperature vs. Sensor Output Voltage (Typical Case)
10°
C after bandgap calibration.
Table 19-2 on page 153
T = { [ (ADCH << 8) | ADCL ] - TOS } / k
ADC
247 mV
-40 °C
=
(
---------------------------------------------------- - GAIN
V
POS
–
V
V
REF
NEG
are typical values. However, due to the process
) 512
⋅
NEG
°
314 mv
C and the accuracy of the temperature
+25 °C
⋅
the voltage on the negative input pin,
ATtiny261/461/861
382 mV
+85 °C
Table 19-2 on
153