PIC18F4431-I/P Microchip Technology Inc., PIC18F4431-I/P Datasheet - Page 203

• Manufacturer Part Number: PIC18F4431-I/P
• Description: Microcontroller; 16 KB Flash; 768 RAM; 256 EEPROM; 36 I/O; 40-Pin-PDIP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4431-I/P

• A/d Inputs: 9-Channel, 10-Bit
• Cpu Speed: 10 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 36
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 16K Bytes
• Ram Size: 768 Bytes
• Speed: 40 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

TABLE 17-3:
 2003 Microchip Technology Inc.
(MHz)
Fosc
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
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
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
Time Min
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
200 ns
400 ns
800 ns
400 ns
800 ns
1.6 µs
1.6 µs
3.2 µs
0.5 µs
Dead
50 ns
80 ns
1 µs
2 µs
4 µs
400
800
Time Max
102.4 µs
102.4 µs
204.8 µs
12.8 µs
25.6 µs
5.12 vs
10.2 µs
20.5 µs
12.8 µs
25.6 vs
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
PIC18F2331/2431/4331/4431
Dead
16 µs
32 µs
41 µs
32 µs
64 µs
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 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 mode, each duty cycle generator 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
PDC0 register to set the duty cycle, PWM3 and PWM2
with PDC1, PWM5 and PWM4 with PDC2, PWM7 and
PWM6 with PDC3, see Figure 17-3 and Register 17-3.
Note 1: For small PWM duty cycles, the ratio of
2: Changing the dead time values in
Independent PWM Output
DEAD TIME DISTORTION
DUTY CYCLE ASSIGNMENT IN THE
INDEPENDENT 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 out-
puts pairs, then that PWM pair will be
inactive for the whole period.
DTCON when the PWM is enabled may
result in undesired situation. Disable the
PWM (PTEN = 0) before changing the
dead time value
DS39616B-page 201