AT90PWM81 Atmel Corporation, AT90PWM81 Datasheet - Page 152

• 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

13.5.2.1
152
AT90PWM81
Four Ramp Mode
The waveform frequency is defined by the following equation:
In Four Ramp mode, each time in a cycle has its own definition
Figure 13-4.
The input clock of PSCR is given by CLKPSC.
PSCOUTr0 and PSCOUTr1 signals are defined by On-Time 0, Dead-Time 0, On-Time 1 and Dead-Time
1 values with :
On-Time 0 = OCRrRAH/L * 1/Fclkpsc
On-Time 1 = OCRrRBH/L * 1/Fclkpsc
Dead-Time 0 = (OCRrSAH/L + 2) * 1/Fclkpsc
Dead-Time 1 = (OCRrSBH/L + 2) * 1/Fclkpsc
Note:
PSC Counter
PSCOUTn0
PSCOUTn1
Minimal value for Dead-Time 0 and Dead-Time 1 = 2 * 1/Fclkpsc
OCRnSA
0
PSCr0 & PSCr1 Basic Waveforms in Four Ramp mode
Dead-Time 0
f
PSCn
=
On-Time 0
----------------------------- -
PSCnCycle
PSC Cycle
1
OCRnRA
=
-------------------------------------------------------------------- -
(
0
OT0
OCRnSB
Dead-Time 1
+
OT1
f
CLK_PSCn
+
DT0
On-Time 1
OCRnRB
+
DT1
)
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