ATtiny48 Atmel Corporation, ATtiny48 Datasheet - Page 44

• Manufacturer Part Number: ATtiny48
• Manufacturer: Atmel Corporation

Specifications of ATtiny48

• Flash (kbytes): 4 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 12 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 28
• Ext Interrupts: 28
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• 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: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

8.2.2
8.2.3
44
ATtiny48/88
External Reset
Brown-Out Detection
An External Reset is generated by a low level on the RESET pin. Reset pulses longer than the
minimum pulse width (see
running. Shorter pulses are not guaranteed to generate a reset. When the applied signal
reaches the Reset Threshold Voltage – V
MCU after the Time-out period – t
RSTDISBL fuse, see
Figure 8-4.
ATtiny48/88 has an On-chip Brown-out Detection (BOD) circuit for monitoring the V
ing 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
V
value below the trigger level (V
When V
MCU after the Time-out period t
The BOD circuit will only detect a drop in V
ger than t
Figure 8-5.
BOT
+ V
CC
HYST
BOD
CC
increases above the trigger level (V
/2 and V
given in
External Reset During Operation
Brown-out Reset During Operation
INTERNAL
TIME-OUT
RESET
RESET
V
CC
Table 20-4 on page
BOT-
“System and Reset Characterizations” on page
= V
Table 22-3 on page
BOT
BOT-
TOUT
TOUT
- V
in
HYST
has expired.
Figure
V
– has expired. The External Reset can be disabled by the
BOT-
/2. When the BOD is enabled, and V
RST
189.
CC
8-5), the Brown-out Reset is immediately activated.
– on its positive edge, the delay counter starts the
if the voltage stays below the trigger level for lon-
209) will generate a reset, even if the clock is not
BOT+
in
Figure
V
t
TOUT
8-5), the delay counter starts the
BOT+
209.
CC
decreases to a
8008H–AVR–04/11
CC
level dur-
BOT+
=