ATMEGA103L-4AI Atmel, ATMEGA103L-4AI Datasheet - Page 27

• Manufacturer Part Number: ATMEGA103L-4AI
• Description: IC MCU 128K 4MHZ A/D LV 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA103L-4AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• For Use With: ATSTK501 - ADAPTER KIT FOR 64PIN AVR MCU
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Power-on Reset
0945I–AVR–02/07
Table 5. Reset Characteristics (V
Note:
A Power-on Reset (POR) circuit ensures that the device is Reset from Power-on. As
shown in Figure 23, an internal timer clocked from the Watchdog Timer Oscillator pre-
vents the MCU from starting until after a certain period after V
on Threshold voltage (V
bits SUT1 and SUT0 are used to select start-up time as indicated in Table 5. A “0” in the
table indicates that the fuse is programmed.
The user can select the start-up time according to typical Oscillator start-up time. The
number of WDT Oscillator cycles used for each Time-out except for SUT = 00 is shown
in Table 6. The frequency of the Watchdog Oscillator is voltage-dependent as shown in
“Typical Characteristics” on page 123.
Table 6. Number of Watchdog Oscillator Cycles
The setting SUT 1/0 = 00 starts the MCU after 5 CPU clock cycles, and can be used
when an external clock signal is applied to the XTAL1 pin. This setting does not use the
WDT Oscillator and enables very fast start-up from the sleep modes Power-down or
Power-save if the clock signal is present during sleep. For details, refer to the program-
ming specification starting on page 104.
If the built-in start-up delay is sufficient, RESET can be connected to V
an external pull-up resistor. By holding the pin low for a period after V
applied, the Power-on Reset period can be extended. Refer to Figure 25 for a timing
example of this.
Symbol
V
V
T
SUT 1/0
01
10
11
TOUT
POT
RST
(1)
1. The Power-on Reset will not work unless the supply voltage has been below V
(falling).
Parameter
Power-on Reset Threshold
(rising)
Power-on Reset Threshold
(falling)
RESET Pin Threshold Voltage
Reset Delay Time-out Period
Time-out at V
0.5 ms
4.0 ms
16.0 ms
POT
), regardless of the V
CC
= 5V
CC
= 5.0V)
Condition
SUT = 00
SUT = 01
SUT = 10
SUT = 11
CC
Number of WDT Cycles
512
4K
16K
rise time (see Figure 24). The Fuse
12.8
Min
1.0
0.4
0.4
3.2
ATmega103(L)
CC
V
16.0
Typ
1.4
0.6
0.5
4.0
CC
5
has reached the Power-
/2
Max
19.2
1.8
0.8
0.6
4.8
CC
directly or via
CC
CPU cycles
has been
Units
ms
V
V
V
POT
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