ATMEGA406-1AAU Atmel, ATMEGA406-1AAU Datasheet - Page 121

• Manufacturer Part Number: ATMEGA406-1AAU
• Description: IC AVR MCU 40K 1MHZ 48LQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA406-1AAU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 1MHz
• Connectivity: I²C
• Peripherals: POR, WDT
• Number Of I /o: 18
• Program Memory Size: 40KB (20K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 25 V
• Data Converters: A/D 10x12b
• Oscillator Type: Internal
• Operating Temperature: -30°C ~ 85°C
• Package / Case: 48-LQFP
• Processor Series: ATMEGA48x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: 2-Wire
• Maximum Clock Frequency: 1 MHz
• Number Of Programmable I/os: 18
• 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
• Minimum Operating Temperature: - 30 C
• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 1MHz
• Total Internal Ram Size: 2KB
• # I/os (max): 18
• Number Of Timers - General Purpose: 2
• Operating Supply Voltage (typ): 5/9/12/15/18/24V
• Operating Supply Voltage (max): 25V
• Operating Supply Voltage (min): 4V
• On-chip Adc: 10-chx12-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -30C to 85C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 48
• Package Type: LQFP
• Controller Family/series: AVR MEGA
• No. Of I/o's: 18
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 2KB
• Cpu Speed: 1MHz
• Rohs Compliant: Yes
• For Use With: 770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPI
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

21. Voltage Reference and Temperature Sensor
21.1
2548E–AVR–07/06
Features
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A low power band-gap reference provides ATmega406 with an accurate On-chip voltage refer-
ence V
Regulator, the V-ADC and the CC-ADC. The reference to the ADCs uses a buffer with external
decoupling capacitor to enable excellent noise performance with minimum power consumption.
The reference voltage V
ment at the current sense input pins. This configuration also enables concurrent operation of
both V-ADC and CC-ADC.
To guaranty ultra low temperature drift after factory calibration, ATmega406 features a two-step
calibration algorithm. The first step is performed at 85°C and the second at room temperature.
By default, Atmel factory calibration is performed at 85°C, and the result is stored in Flash. The
customer can easily implement the second calibration step in their test flow. This requires an
accurate input voltage and a stable room temperature. Temperature drift after this calibration is
guarantied by design and characterization to be less than 80 ppm/°C from 0°C to 60°C and 100
ppm/°C from 0°C to 85°C. The BG Calibration C Register can also be altered runtime to imple-
ment temperature compensation in software. Very high accuracy for any temperature inside the
temperature range can thus be achieved at the cost of extra calibration steps.
A lower power, less accurate voltage reference source exists. This voltage reference source is
chosen as reference for the voltage regulator whenever the band-gap voltage reference is dis-
abled. This voltage reference source is not available for the V-ADC and CC-ADC.
ATmega406 has an On-chip temperature sensor for monitoring the die temperature. A voltage
Proportional-To-Absolute-Temperature, V
connected to the multiplexer at the V-ADC input. This temperature sensor can be used for runt-
ime compensation of temperature drift in both the voltage reference and the On-chip Oscillator.
To get the absolute temperature in degrees Kelvin, the measured V
with the VPTAT factory calibration value stored in the signature row. See
Row from Software” on page 189
Accurate Voltage Reference of 1.100V
± 0.1% Accuracy After Calibration (2 mV Calibration Steps)
Temperature Drift Less than 80 ppm/°C after Calibration
Alternate Low Power Voltage Reference for Voltage Regulator
Internal Temperature Sensor
Possibility for Runtime Compensation of Temperature Drift in Both Voltage Reference and On-
chip Oscillators
External Decoupling for Optimum Noise Performance
Low Power Consumption
REF
of 1.100V. This reference voltage is used as reference for the On-chip Voltage
REF_P
/V
REF_N
for details.
to the CC-ADC is scaled to match the full scale require-
PTAT
, is generated in the voltage reference circuit and
PTAT
voltage must be scaled
”Reading the Signature
ATmega406
121