ATmega48 Atmel Corporation, ATmega48 Datasheet - Page 34

• Manufacturer Part Number: ATmega48
• Manufacturer: Atmel Corporation

Specifications of ATmega48

• Flash (kbytes): 4 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 20 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 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 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

9.7
2545T–AVR–05/11
128kHz internal oscillator
Table 9-8.
Notes:
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 9-9.
Note:
The 128kHz internal oscillator is a low power oscillator providing a clock of 128kHz. The fre-
quency is nominal at 3V and 25°C. This clock may be select as the system clock by
programming the CKSEL fuses to “11” as shown in
Table 9-10.
Note:
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 9-11.
Note:
Power conditions
BOD enabled
Fast rising power
Slowly rising power
BOD enabled
Fast rising power
Slowly rising power
Power conditions
9-9.
9-11.
1. The device is shipped with this option selected.
2. If 8MHz frequency exceeds the specification of the device (depends on V
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to
2. The device is shipped with this option selected.
1. Note that the 128kHz oscillator is a very low power clock source, and is not designed for a high
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to
Fuse can be programmed in order to divide the internal frequency by 8.
14CK + 4.1ms to ensure programming mode can be entered.
accuracy.
14CK + 4.1ms to ensure programming mode can be entered.
Frequency range (MHz)
Internal calibrated RC oscillator operating modes
Start-up times for the internal calibrated RC Oscillator clock selection.
128kHz internal oscillator operating modes.
Start-up times for the 128kHz internal oscillator.
7.3 - 8.1
Nominal frequency
128kHz
power-down and power-save
power-down and power-save
Start-up time from
Start-up time from
Reserved
Reserved
6CK
6CK
6CK
6CK
6CK
6CK
Table
9-10.
Additional delay from
Additional delay from
ATmega48/88/168
reset (V
(1)(2)
14CK + 65ms
14CK + 4.1ms
14CK + 64ms
14CK + 4ms
.
CKSEL3..0
14CK
14CK
reset
0010
CC
CKSEL3..0
(1)
= 5.0V)
(1)
0011
(2)
CC
), the CKDIV8
SUT1..0
SUT1..0
00
01
10
11
00
01
10
11
34