ATMEGA48A-AU Atmel, ATMEGA48A-AU Datasheet - Page 28

IC MCU AVR 4K FLASH 32TQFP

ATMEGA48A-AU

Manufacturer Part Number
ATMEGA48A-AU
Description
IC MCU AVR 4K FLASH 32TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets

Specifications of ATMEGA48A-AU

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 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
32-TQFP, 32-VQFP
Controller Family/series
Atmega
No. Of I/o's
23
Eeprom Memory Size
256Byte
Ram Memory Size
512Byte
Cpu Speed
20MHz
Rohs Compliant
Yes
Processor Series
ATmega
Core
AVR
Data Bus Width
8 bit
Data Ram Size
512 B
Interface Type
TWI, SPI, USART
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
23
Number Of Timers
3
Operating Supply Voltage
3.3 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
Operating Temperature Range
- 40 C to + 85 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
ATMEGA48A-AU
Manufacturer:
Atmel
Quantity:
10 000
Part Number:
ATMEGA48A-AUR
Manufacturer:
Atmel
Quantity:
10 000
8.3
8271C–AVR–08/10
Low Power Crystal Oscillator
selectable delays are shown in
dependent as shown in
Table 8-2.
Main purpose of the delay is to keep the AVR in reset until it is supplied with minimum V
delay will not monitor the actual voltage and it will be required to select a delay longer than the
V
used. A BOD circuit will ensure sufficient V
can be disabled. Disabling the time-out delay without utilizing a Brown-Out Detection circuit is
not recommended.
The oscillator is required to oscillate for a minimum number of cycles before the clock is consid-
ered stable. An internal ripple counter monitors the oscillator output clock, and keeps the internal
reset active for a given number of clock cycles. The reset is then released and the device will
start to execute. The recommended oscillator start-up time is dependent on the clock type, and
varies from 6 cycles for an externally applied clock to 32K cycles for a low frequency crystal.
The start-up sequence for the clock includes both the time-out delay and the start-up time when
the device starts up from reset. When starting up from Power-save or Power-down mode, V
assumed to be at a sufficient level and only the start-up time is included.
Pins 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
crystal or a ceramic resonator may be used.
This Crystal Oscillator is a low power oscillator, with reduced voltage swing on the XTAL2 out-
put. It gives the lowest power consumption, but is not capable of driving other clock inputs, and
may be more susceptible to noise in noisy environments. In these cases, refer to the
Crystal Oscillator” on page
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
ues given by the manufacturer should be used.
ATmega48A/48PA/88A/88PA/168A/168PA/328/328
CC
Typ Time-out (V
rise time. If this is not possible, an internal or external Brown-Out Detection circuit should be
4.1 ms
65 ms
0 ms
Number of Watchdog Oscillator Cycles
CC
= 5.0V)
”Typical Characteristics” on page
30.
Table 8-3 on page
Table
Typ Time-out (V
8-2. The frequency of the Watchdog Oscillator is voltage
CC
4.3 ms
69 ms
before it releases the reset, and the time-out delay
0 ms
29. For ceramic resonators, the capacitor val-
CC
= 3.0V)
Figure 8-2 on page
331.
Number of Cycles
8K (8,192)
29. Either a quartz
512
0
”Full Swing
CC
. The
CC
28
is

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