ATmega48 Atmel Corporation, ATmega48 Datasheet - Page 322

• 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

30.3.0.1
30.3.0.2
30.3.0.3
2545T–AVR–05/11
Example 1
Example 2
Example 3
Table 30-2.
It is possible to calculate the typical current consumption based on the numbers from
on page 321
Calculate the expected current consumption in idle mode with USART0, TIMER1, and TWI
enabled at V
we need to add 18% for the USART0, 26% for the TWI, and 11% for the TIMER1 module. Read-
ing from
= 3.0V and F = 1MHz. The total current consumption in idle mode with USART0, TIMER1, and
TWI enabled, gives:
Same conditions as in example 1, but in active mode instead. From
second column we see that we need to add 3.3% for the USART0, 4.8% for the TWI, and 2.0%
for the TIMER1 module. Reading from
consumption is ~0.42mA at V
mode with USART0, TIMER1, and TWI enabled, gives:
All I/O modules should be enabled. Calculate the expected current consumption in active mode
at V
to be ~ 4.0mA (from
page 321
I
I
I
CC
CC
CC
PRR bit
PRTIM1
PRTIM0
PRSPI
PRADC
total
total
total
CC
≈
≈
≈
= 3.6V and F = 10MHz. We find the active current consumption without the I/O modules
0.075mA
0.42mA
4.0mA
Figure 30-7 on page
- second column, we find the total current consumption:
CC
for other V
•
Additional current consumption (percentage) in active and idle mode. (Continued)
•
(
Additional current consumption
compared to active with external clock
(see
Figure 30-2 on page
4.9%
= 3.0V and F = 1MHz. From
2.0%
1.6%
6.1%
•
1
(
1
(
+
1
+
0.033
+
Figure 30-1 on page 315
0.033
Figure 30-2 on page
0.18
CC
+
+
+
and frequency settings than listed in
0.048
0.26
0.048
318, we find that the idle current consumption is ~0.075mA at V
CC
+
+
+
= 3.0V and F = 1MHz. The total current consumption in idle
0.11
0.047
0.02
316)
)
Figure 30-1 on page
)
≈
+
≈
0.116mA
0.02
316). Then, by using the numbers from
0.46mA
and
Table 30-2 on page
+
0.016
+
0.061
Additional current consumption
compared to Idle with external clock
(see
Figure 30-8 on page
11%
8.5%
33%
26%
+
315, we find that the active current
Figure 30-7 on page 318
ATmega48/88/168
0.049
Table 30-1 on page
321, third column, we see that
)
≈
5.1mA
Table 30-2 on page
319)
Table 30-2 on
321.
and
Table 30-2
321,
322
CC