ATTINY461-20SUR Atmel, ATTINY461-20SUR Datasheet - Page 30

• Manufacturer Part Number: ATTINY461-20SUR
• Description: MCU AVR 4KB FLASH 20MHZ 20SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY461-20SUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6.2.6
30
ATtiny261/461/861
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 6-4.
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
the manufacturer should be used.
Table 6-11.
Notes:
The Oscillator can operate in three different modes, each optimized for a specific frequency
range. The operating mode is selected by fuses CKSEL3:1 as shown in
The CKSEL0 Fuse together with the SUT1:0 Fuses select the start-up times as shown in
6-12.
Table 6-12.
CKSEL0
CKSEL3:1
100
0
0
0
101
110
111
(1)
1. This option should not be used with crystals, only with ceramic resonators.
SUT1:0
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
Power-down and
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
1K (1024) CK
Power-save
Table
8.0 -
258 CK
258 CK
6-11. For ceramic resonators, the capacitor values given by
(1)
(1)
C2
C1
(2)
Additional Delay
14CK + 64 ms
14CK + 4 ms
(V
from Reset
CC
Recommended C1 and C2 Value (pF)
XTAL2
XTAL1
GND
Figure
14CK
= 5.0V)
6-4. Either a quartz crystal or a
12 - 22
12 - 22
12 - 22
Recommended Usage
Ceramic resonator,
fast rising power
Ceramic resonator,
slowly rising power
Ceramic resonator,
BOD enabled
–
Table
6-11.
2588E–AVR–08/10
Table