ATTINY25-20SUR Atmel, ATTINY25-20SUR Datasheet - Page 30

• Manufacturer Part Number: ATTINY25-20SUR
• Description: MCU AVR 2KB FLASH 20MHZ 8SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY25-20SUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 6
• Program Memory Size: 2KB (1K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6.2.6
30
ATtiny25/45/85
Crystal Oscillator / Ceramic Resonator
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can be con-
figured for use as an On-chip Oscillator, as shown in
ceramic resonator may be used.
Figure 6-5.
C1 and C2 should always be equal for both crystals and resonators. The optimal value of the
capacitors depends on the crystal or resonator in use, the amount of stray capacitance, and the
electromagnetic noise of the environment. Some initial guidelines for choosing capacitors for
use with crystals are given in
given by the manufacturer should be used.
Table 6-12.
Notes:
The Oscillator can operate in three different modes, each optimized for a specific frequency
range. The operating mode is selected by the fuses CKSEL[3:1] as shown in
The CKSEL0 Fuse together with the SUT[1:0] Fuses select the start-up times as shown in
6-13.
Table 6-13.
CKSEL[3:1]
CKSEL0
100
0
0
0
101
110
111
(1)
1. This option should not be used with crystals, only with ceramic resonators.
SUT[1:0]
Crystal Oscillator Connections
Crystal Oscillator Operating Modes
Start-up Times for the Crystal Oscillator Clock Selection
00
01
10
Frequency Range (MHz)
Start-up Time from
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
1K (1024) CK
Power-down
8.0 -
Table 6-12
258 CK
258 CK
(1)
(1)
C2
C1
(2)
below. For ceramic resonators, the capacitor values
Additional Delay
Recommended Range for Capacitors C1 and
14CK + 64 ms
14CK + 4 ms
from Reset
XTAL2
XTAL1
GND
Figure
14CK
C2 for Use with Crystals (pF)
6-5. Either a quartz crystal or a
12 - 22
12 - 22
12 - 22
Ceramic resonator,
fast rising power
Ceramic resonator,
slowly rising power
Ceramic resonator,
BOD enabled
Recommended Usage
–
Table
2586M–AVR–07/10
6-12.
Table