ATMEGA48A-PU Atmel, ATMEGA48A-PU Datasheet - Page 34

• Manufacturer Part Number: ATMEGA48A-PU
• Description: IC MCU AVR 4K FLASH 28PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48A-PU

• 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): 1.8 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-DIP (0.300", 7.62mm)
• Controller Family/series: Atmega
• No. Of I/o's: 23
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 512Byte
• Cpu Speed: 20MHz
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.7
8.8
8271C–AVR–08/10
128 kHz Internal Oscillator
External Clock
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 8-12.
Note:
The 128 kHz internal Oscillator is a low power Oscillator providing a clock of 128 kHz. 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 8-13.
Note:
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 8-14.
Note:
To drive the device from an external clock source, XTAL1 should be driven as shown in
8-4. To run the device on an external clock, the CKSEL Fuses must be programmed to “0000”
(see
Table 8-15.
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
Power Conditions
BOD enabled
Fast rising power
Slowly rising power
BOD enabled
Fast rising power
Slowly rising power
Power Conditions
Table
8-12.
8-14.
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to
2.
1. Note that the 128 kHz oscillator is a very low power clock source, and is not designed for high
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to
The device is shipped with this option selected.
8-15).
14CK + 4.1 ms to ensure programming mode can be entered.
accuracy.
14CK + 4.1 ms to ensure programming mode can be entered.
Start-up times for the internal calibrated RC Oscillator clock selection
128 kHz Internal Oscillator Operating Modes
Start-up Times for the 128 kHz Internal Oscillator
Crystal Oscillator Clock Frequency
Nominal Frequency
Frequency
0 - 20 MHz
128 kHz
Start-up Time from Power-
Start-up Time from Power-
down and Power-save
down and Power-save
Reserved
(1)
Reserved
6 CK
6 CK
6 CK
6 CK
6 CK
6 CK
Table
8-13.
Additional Delay from
Additional Delay from
Reset (V
14CK + 65 ms
14CK + 4.1 ms
14CK + 64 ms
14CK + 4 ms
14CK
14CK
Reset
CC
CKSEL3...0
CKSEL3...0
(1)
(1)
= 5.0V)
0011
0000
(2)
SUT1...0
SUT1...0
00
01
10
11
Figure
00
01
10
11
34