AT90PWM81 Atmel Corporation, AT90PWM81 Datasheet - Page 32

• Manufacturer Part Number: AT90PWM81
• Manufacturer: Atmel Corporation

Specifications of AT90PWM81

• Flash (kbytes): 8 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 20
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 11
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 3
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 125
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 1
• Output Compare Channels: 8
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

32
AT90PWM81
The Oscillator can operate in three different modes, each optimized for a specific frequency range. The
operating mode is selected by CKSEL3..1 fuses or by CSEL3..1 field as shown in
Table 5-6.
Notes:
The CKSEL0 Fuse together with the SUT1..0 Fuses or CSEL0 together with CSUT1..0 field select the
start-up times as shown in
Table 5-7.
Notes:
CKSEL0
CSEL0
CKSEL3..1
CSEL3..1
0
0
0
0
1
1
1
1
100
101
110
111
1. Flash Fuse bits.
2. CLKSELR register bits.
3. This option should not be used with crystals, only with ceramic resonators.
1. Flash Fuse bits.
2. CLKSELR register bits.
3. These options should only be used when not operating close to the maximum frequency of the device,
4. These options are intended for use with ceramic resonators and will ensure frequency stability at start-
(2)
(1)
(3)
and only if frequency stability at start-up is not important for the application. These options are not suit-
able for crystals.
up. They can also be used with crystals when not operating close to the maximum frequency of the
device, and if frequency stability at start-up is not important for the application.
(2)
(1)
Crystal Oscillator Operating Modes
Start-up Times for the Crystal Oscillator Clock Selection
CSUT1..0
SUT1..0
00
01
10
00
01
10
11
11
Frequency Range (MHz)
(1)
(2)
Table
8.0 - 16.0
5-7.
0.4 - 0.9
0.9 - 3.0
3.0 - 8.0
Start-up Time from
Power-down and
16K (16384) CK
16K (16384) CK
16K (16384) CK
1K (1024) CK
1K (1024)CK
1K (1024)CK
Power-save
258 CK
258 CK
(3)
(3)
(4)
(4)
(4)
Additional Delay
14CK + 4.1 ms
14CK + 4.1 ms
14CK + 4.1 ms
14CK + 65 ms
14CK + 65 ms
14CK + 65 ms
(Vcc = 5.0V)
from Reset
C1 and C2 for Use with Crystals (pF)
Recommended Range for Capacitors
14CK
14CK
12 - 22
12 - 22
12 - 22
Recommended Usage
Ceramic resonator, fast
rising power
Ceramic resonator, slowly
rising power
Ceramic resonator, BOD
enabled
Ceramic resonator, fast
rising power
Ceramic resonator, slowly
rising power
Crystal Oscillator, BOD
enabled
Crystal Oscillator, fast
rising power
Crystal Oscillator, slowly
rising power
–
Table
5-6.
7734P–AVR–08/10