ATtiny43U Atmel Corporation, ATtiny43U Datasheet - Page 50

• Manufacturer Part Number: ATtiny43U
• Manufacturer: Atmel Corporation

Specifications of ATtiny43U

• Flash (kbytes): 4 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 8 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 4
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 0.7 to 5.5
• Operating Voltage (vcc): 0.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

9.4
9.5
50
External Reset
Brown-out Detection
ATtiny43U
An External Reset is generated by a low level on the RESET pin if enabled. Reset pulses longer
than the minimum pulse width (see
clock is not running. Shorter pulses are not guaranteed to generate a reset. When the applied
signal reaches the Reset Threshold Voltage – V
starts the MCU after the Time-out period – t
Figure 9-4.
ATtiny43U has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
operation by comparing it to a fixed trigger level. The trigger level for the BOD can be selected
by the BODLEVEL Fuses. The trigger level has a hysteresis to ensure spike free Brown-out
Detection. The hysteresis on the detection level should be interpreted as V
and V
When the BOD is enabled, and V
9-5 on page
trigger level (V
out period t
The BOD circuit will only detect a drop in V
ger than t
Figure 9-5.
BOT-
BOD
= V
TOUT
CC
50), the Brown-out Reset is immediately activated. When V
INTERNAL
TIME-OUT
given in
BOT
External Reset During Operation
Brown-out Reset During Operation
BOT+
RESET
RESET
has expired.
- V
V
CC
in
HYST
Figure 9-5 on page
Table 20-4 on page
/2.
CC
decreases to a value below the trigger level (V
Table 20-4 on page
V
BOT-
50), the delay counter starts the MCU after the Time-
158.
CC
TOUT
if the voltage stays below the trigger level for lon-
– has expired.
RST
– on its positive edge, the delay counter
158) will generate a reset, even if the
V
t
TOUT
BOT+
CC
BOT+
increases above the
= V
CC
8048B–AVR–03/09
BOT
BOT-
level during
+ V
in
Figure
HYST
/2