ATmega48 Automotive Atmel Corporation, ATmega48 Automotive Datasheet - Page 27

• Manufacturer Part Number: ATmega48 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega48 Automotive

• Flash (kbytes): 4 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• 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): 0.5
• Eeprom (bytes): 256
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 125
• 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: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

7.4
7701E–AVR–02/11
Crystal Oscillator
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can be
configured for use as an On-chip Oscillator, as shown in Figure 7-2. Either a quartz crystal or
a ceramic resonator may be used.
C1 and C2 should always be equal for both crystals and resonators. The optimal value of the
capacitors depends on the crystal or resonator in use, the amount of stray capacitance, and
the electromagnetic noise of the environment. Some initial guidelines for choosing capacitors
for use with crystals are given in
values given by the manufacturer should be used.
Figure 7-2.
The Oscillator can operate in three different modes, each optimized for a specific frequency
range. The operating mode is selected by the fuses CKSEL3..1 as shown in
page
Table 7-3.
Notes:
The CKSEL0 Fuse together with the SUT1..0 Fuses select the start-up times as shown in
Table 7-4 on page
CKSEL3..1
100
101
110
111
27.
(1)
1. This option should not be used with crystals, only with ceramic resonators.
Crystal Oscillator Connections
Crystal Oscillator Operating Modes
28.
Frequency Range (MHz)
Atmel ATtiny24/44/84 [Preliminary]
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
8.0 -
Table 7-3 on page
C2
C1
Recommended Range for Capacitors C1 and
27. For ceramic resonators, the capacitor
XTAL2
XTAL1
GND
C2 for Use with Crystals (pF)
12 - 22
12 - 22
12 - 22
–
Table 7-3 on
27