ATtiny85 Atmel Corporation, ATtiny85 Datasheet - Page 29

• Manufacturer Part Number: ATtiny85
• Manufacturer: Atmel Corporation

Specifications of ATtiny85

• Flash (kbytes): 8 Kbytes
• Pin Count: 8
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 3
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 6
• Ext Interrupts: 6
• 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): 0.5
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• 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: 5
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

6.2.4
6.2.5
2586N–AVR–04/11
Internal 128 kHz Oscillator
Low-Frequency Crystal Oscillator
The 128 kHz internal Oscillator is a low power Oscillator providing a clock of 128 kHz. The fre-
quency is nominal at 3V and 25°C. This clock may be select as the system clock by
programming the CKSEL Fuses to “0100”.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table
Table 6-9.
Note:
To use a 32.768 kHz watch crystal as the clock source for the device, the Low-frequency Crystal
Oscillator must be selected by setting CKSEL fuses to ‘0110’. The crystal should be connected
as shown in
the manufacturer’s datasheet.
When this oscillator is selected, start-up times are determined by the SUT fuses as shown in
Table
Table 6-10.
Note:
The Low-frequency Crystal Oscillator provides an internal load capacitance, see
each TOSC pin.
Table 6-11.
SUT[1:0]
SUT[1:0]
00
01
10
11
00
01
10
11
ATtiny25/45/85
6-9.
6-10.
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to 14CK + 4 ms to
1. These options should be used only if frequency stability at start-up is not important.
Device
ensure programming mode can be entered.
Figure
Start-up Time from
Start-up Times for the 128 kHz Internal Oscillator
Start-up Times for the Low Frequency Crystal Oscillator Clock Selection
Capacitance of Low-Frequency Crystal Oscillator
32K (32768) CK
1K (1024) CK
1K (1024) CK
Power Down
Start-up Time from
6-5. To find suitable load capacitance for a 32.768 kHz crysal, please consult
Power-down
6 CK
6 CK
6 CK
(1)
(1)
32 kHz Osc. Type
System Osc.
Additional Delay from
Reset (V
64 ms
64 ms
4 ms
Additional Delay from
CC
= 5.0V)
Reserved
Reserved
14CK + 64 ms
14CK + 4 ms
14CK
Reset
Cap (Xtal1/Tosc1)
(1)
Recommended usage
Fast rising power or BOD enabled
Slowly rising power
Stable frequency at start-up
16 pF
ATtiny25/45/85
BOD enabled
Fast rising power
Slowly rising power
Recommended Usage
6 pF
Cap (Xtal2/Tosc2)
Table 6-11
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