ATmega406 Atmel Corporation, ATmega406 Datasheet - Page 18

• Manufacturer Part Number: ATmega406
• Manufacturer: Atmel Corporation

Specifications of ATmega406

• Flash (kbytes): 40 Kbytes
• Pin Count: 48
• Max. Operating Frequency: 1 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 18
• Ext Interrupts: 4
• Usb Speed: No
• Usb Interface: No
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 12
• Adc Speed (ksps): 1.9
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 2
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -30 to 85
• I/o Supply Class: 4.0 to 25
• Operating Voltage (vcc): 4.0 to 25
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 3
• Pwm Channels: 2
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

18
ATmega406
Figure 8-1.
2. Voltage Reference spike
Problem Fix/Workaround
Avoid getting unbalanced cells by using the internal cell balancing FETs.
The Voltage Reference, VREF, will spike each time the internal temperature sensor is
enabled. The temperature sensor is enabled when the VTEMP is selected in the VADMUX
register and the V-ADC is enabled by the VADEN bit.
The spike will be approximately 50mV and lasts for about 5ms, and it will affect any ongoing
current accumulation in the CC-ADC, as well as V-ADC conversions in the period of the
spike.
Figure 9-2 on page 19
CM Offset with unbalanced cells.
illustrates the Voltage Reference spike.
2548ES–AVR–07/06