AT90LS4433-4AC Atmel, AT90LS4433-4AC Datasheet - Page 120

• Manufacturer Part Number: AT90LS4433-4AC
• Description: IC MCU 4K 4MHZ A/D LV 32TQFP
• Manufacturer: Atmel
• Series: AVR® 90LSr

Specifications of AT90LS4433-4AC

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 20
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 6 V
• Data Converters: A/D 6x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 32-TQFP, 32-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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AT90S/LS4433
3. Brown-out Detection Level
2. Serial Programming at Voltages below 2.9V
1. UART Loses Synchronization if RXD Line is Low when UART Receive is
The Brown-out Detection level can increase when there is heavy I/O-activity on the
device. The increase can be significant when some of the I/O pins are driving heavy
loads.
Problem Fix/Workaround
Select a V
Avoid loading I/O ports with high capacitive or resistive loads.
At voltages below 2.9V, serial programming might fail.
Problem Fix/Workaround
Keep V
Disabled
The UART will detect a UART start bit and start reception even if the UART is not
enabled. If this occurs, the first byte after reenabling the UART will be corrupted.
Problem Fix/Workaround
Make sure that the RX line is high at start-up and when the UART is disabled. An
external RS-232 level converter keeps the line high during start-up.
CC
CC
at 2.9V or higher during In-System Programming.
well above the Brown-out Detection level.
1042H–AVR–04/03