AT90PWM1-16MU Atmel, AT90PWM1-16MU Datasheet - Page 135

• Manufacturer Part Number: AT90PWM1-16MU
• Description: IC AVR PWM 8KB FLASH 16MHZ 32QFN
• Manufacturer: Atmel
• Series: AVR® 90PWM Lightingr

Specifications of AT90PWM1-16MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 19
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

16.7.1
4378C–AVR–09/08
Frequency distribution
The frequency modulation is done by switching two frequencies in a 16 consecutive cycle frame.
These two frequencies are f
frequency and f
in the frame is (d-16) and the number of f
uted in the frame according to a predefined pattern. This pattern can be as given in the following
table or by any other implementation which give an equivallent evenly distribution.
Table 38.
While ‘X’ in the table, f
So for each row, a number of fb2 take place of fb1.
Figure 16-12. Resulting Frequency versus d.
Distribution of fb2 in the modulated frame
Fraction
al
Divider
(d)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
d:
f
b1
0
Distribution of f
PWM - cycle
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
1
b2
2
1
X
X
X
X
X
X
X
is the nearest base frequency below the wanted frequency. The number of f
3
2
X
X
X
X
X
X
X
X
X
X
X
b2
b2
4
prime to f
in the modulated frame
3
X
X
X
b1
5
and f
4
X
X
X
X
X
X
X
X
X
X
X
X
X
6
b1
b2
in cycle corresponding cycle.
7
where f
5
X
X
X
X
X
8
b2
6
X
X
X
X
X
X
X
X
X
is d. The f
b1
9 10 11 12 13 14 15
is the nearest base frequency above the wanted
7
X
8
X
X
X
X
X
X
X
X
X
X
X
X
X
X
b1
and f
9
X
X
X
X
X
X
b2
10
X
X
X
X
X
X
X
X
X
X
frequencies are evenly distrib-
11
X
X
AT90PWM1
f
12
X
X
X
X
X
X
X
X
X
X
X
X
b2
13
X
X
X
X
f
OP
14
X
X
X
X
X
X
X
X
15
135
b1