ATMEGA48-20MI Atmel, ATMEGA48-20MI Datasheet - Page 29

• Manufacturer Part Number: ATMEGA48-20MI
• Description: IC AVR MCU 4K 5V 20MHZ 32-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48-20MI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 23
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: ATMEGA48-24MI; ATMEGA48-24MI

2545S–AVR–07/10
Figure 8-2.
The Low Power Oscillator can operate in three different modes, each optimized for a specific fre-
quency range. The operating mode is selected by the fuses CKSEL3..1 as shown in
on page
Table 8-3.
Notes:
The CKSEL0 Fuse together with the SUT1..0 Fuses select the start-up times as shown in
8-4.
Table 8-4.
Oscillator Source /
Power Conditions
Ceramic resonator, fast
rising power
Ceramic resonator, slowly
rising power
Ceramic resonator, BOD
enabled
Ceramic resonator, fast
rising power
Ceramic resonator, slowly
rising power
Frequency Range
1. This is the recommended CKSEL settings for the different frequency ranges.
2. This option should not be used with crystals, only with ceramic resonators.
3. If 8 MHz frequency exceeds the specification of the device (depends on V
29.
8.0 - 16.0
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
(MHz)
Fuse can be programmed in order to divide the internal frequency by 8. It must be ensured
that the resulting divided clock meets the frequency specification of the device.
Crystal Oscillator Connections
Low Power Crystal Oscillator Operating Modes
Start-up Times for the Low Power Crystal Oscillator Clock Selection
Start-up Time from
Power-down and
Power-save
258 CK
258 CK
1K CK
1K CK
1K CK
Capacitors C1 and C2 (pF)
C2
C1
Recommended Range for
12 - 22
12 - 22
12 - 22
–
Additional Delay
14CK + 4.1 ms
14CK + 4.1 ms
14CK + 65 ms
14CK + 65 ms
(V
from Reset
XTAL2
XTAL1
GND
CC
14CK
= 5.0V)
(3)
ATmega48/88/168
(2)
(1)
(2)
(1)
(2)
CKSEL0
CC
0
0
0
0
1
CKSEL3..1
), the CKDIV8
100
101
110
111
(2)
Table 8-3
SUT1..0
(1)
00
01
10
11
00
Table
29