PIC18F4431-I/ML Microchip Technology, PIC18F4431-I/ML Datasheet - Page 203

• Manufacturer Part Number: PIC18F4431-I/ML
• Description: IC PIC MCU FLASH 8KX16 44QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F4431-I/ML

• Core Size: 8-Bit
• Program Memory Size: 16KB (8K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, Power Control PWM, QEI, POR, PWM, WDT
• Number Of I /o: 36
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 9x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-QFN
• Controller Family/series: PIC18
• No. Of I/o's: 36
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 768Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: EUSART, I2C, SPI, SSP
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 1 x 8
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 9 bit
• Package: 44QFN EP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44QFN2 - SOCKET TRAN ICE 44QFN/40DIPAC164322 - MODULE SOCKET MPLAB PM3 28/44QFN444-1001 - DEMO BOARD FOR PICMICRO MCU
• Lead Free Status / Rohs Status: Details

The actual dead time is calculated from the DTCON
register as follows:
Dead Time = Dead Time Value/(F
Table 17-3 shows example dead-time ranges as a
function of the input clock prescaler selected and the
device operating frequency.
TABLE 17-3:
© 2007 Microchip Technology Inc.
(MHz)
F
OSC
40
40
40
40
32
32
32
32
25
25
25
25
20
20
20
20
10
10
10
10
5
5
5
5
4
4
4
4
MIPS
6.25
6.25
6.25
6.25
1.25
1.25
1.25
1.25
2.5
2.5
2.5
2.5
10
10
10
10
8
8
8
8
5
5
5
5
1
1
1
1
Prescaler
Selection
F
F
F
F
F
F
F
EXAMPLE DEAD-TIME
RANGES
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
F
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
OSC
/16
/16
/16
/16
/16
/16
/16
/2
/4
/8
/2
/4
/8
/2
/4
/8
/2
/4
/8
/2
/4
/8
/2
/4
/8
/2
/4
/8
Dead-Time
62.5 ns
100 ns
200 ns
400 ns
125 ns
250 ns
500 ns
160 ns
320 ns
640 ns
100 ns
200 ns
400 ns
800 ns
200 ns
400 ns
800 ns
400 ns
800 ns
1.6 μs
1.6 μs
3.2 μs
0.5 μs
50 ns
80 ns
1 μs
2 μs
4 μs
Min
OSC
/Prescaler)
Dead-Time
102.4 μs
102.4 μs
204.8 μs
12.8 μs
25.6 μs
5.12 μs
10.2 μs
20.5 μs
12.8 μs
25.6 μs
51.2 μs
12.8 μs
25.6 μs
51.2 μs
25.6 μs
51.2 μs
128 μs
256 μs
3.2 μs
6.4 μs
6.4 μs
32 μs
41 μs
PIC18F2331/2431/4331/4431
16 μs
32 μs
64 μs
Max
4 μs
8 μs
Preliminary
17.7.4
17.8
Independent PWM mode is used for driving the loads
(as shown in Figure 17-19) for driving one winding of a
switched reluctance motor. A particular PWM output
pair is configured in the Independent Output mode
when the corresponding PMOD bit in the PWMCON0
register is set. No dead-time control is implemented
between the PWM I/O pins when the module is operat-
ing in the Independent PWM mode and both I/O pins
are allowed to be active simultaneously. This mode can
also be used to drive stepper motors.
17.8.1
In the Independent PWM mode, each duty cycle gener-
ator is connected to both PWM output pins in a given
PWM output pair. The odd and the even PWM output
pins are driven with a single PWM duty cycle generator.
PWM1 and PWM0 are driven by the PWM channel
which uses the PDC0 register to set the duty cycle,
PWM3 and PWM2 with PDC1, PWM5 and PWM4 with
PDC2 and PWM7 and PWM6 with PDC3 (see
Figure 17-3 and Register 17-4).
Note 1: For small PWM duty cycles, the ratio of
2: Changing
Independent PWM Output
DEAD-TIME DISTORTION
DUTY CYCLE ASSIGNMENT IN THE
INDEPENDENT PWM MODE
dead time to the active PWM time may
become large. In this case, the inserted
dead time will introduce distortion into
waveforms produced by the PWM mod-
ule. The user can ensure that dead-time
distortion is minimized by keeping the
PWM duty cycle at least three times
larger than the dead time. A similar effect
occurs for duty cycles at or near 100%.
The maximum duty cycle used in the
application should be chosen such that
the minimum inactive time of the signal is
at least three times larger than the dead
time. If the dead time is greater or equal
to the duty cycle of one of the PWM
output pairs, then that PWM pair will be
inactive for the whole period.
DTCON when the PWM is enabled may
result in an undesired situation. Disable
the PWM (PTEN = 0) before changing the
dead-time value
the
dead-time
DS39616C-page 201
values
in