PIC18F2550-I/SP Microchip Technology Inc., PIC18F2550-I/SP Datasheet - Page 156

• Manufacturer Part Number: PIC18F2550-I/SP
• Description: Microcontroller; 32 KB Flash; 2048 RAM; 256 EEPROM; 24 I/O; 28-Pin-SPDIP
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F2550-I/SP

• A/d Inputs: 10-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 12 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 23
• Interface: I2C/SPI/USART/USB
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 32K Bytes
• Ram Size: 2K Bytes
• Speed: 48 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F2455/2550/4455/4550
16.4.4
In the Half-Bridge Output mode, two pins are used as
outputs to drive push-pull loads. The PWM output sig-
nal is output on the P1A pin, while the complementary
PWM output signal is output on the P1B pin
(Figure 16-4). This mode can be used for half-bridge
applications, as shown in Figure 16-5, or for full-bridge
applications where four power switches are being
modulated with two PWM signals.
In Half-Bridge Output mode, the programmable
dead-band delay can be used to prevent shoot-through
current in half-bridge power devices. The value of bits
PDC6:PDC0 sets the number of instruction cycles
before the output is driven active. If the value is greater
than the duty cycle, the corresponding output remains
inactive during the entire cycle. See Section 16.4.6
“Programmable Dead-Band Delay” for more details
of the dead-band delay operations.
Since the P1A and P1B outputs are multiplexed with
the PORTC<2> and PORTD<5> data latches, the
TRISC<2> and TRISD<5> bits must be cleared to
configure P1A and P1B as outputs.
FIGURE 16-5:
DS39632C-page 154
Standard Half-Bridge Circuit (“Push-Pull”)
Half-Bridge Output Driving a Full-Bridge Circuit
HALF-BRIDGE MODE
EXAMPLES OF HALF-BRIDGE OUTPUT MODE APPLICATIONS
PIC18FX455/X550
P1A
P1B
PIC18FX455/X550
P1A
P1B
Preliminary
FET
Driver
FET
Driver
FET
Driver
FET
Driver
FIGURE 16-4:
Note 1: At this time, the TMR2 register is equal to the
P1A
P1B
td = Dead-Band Delay
(2)
(2)
2: Output signals are shown as active-high.
(1)
Load
V+
PR2 register.
V-
td
V+
V-
Duty Cycle
Period
Load
td
HALF-BRIDGE PWM
OUTPUT
© 2006 Microchip Technology Inc.
FET
Driver
FET
Driver
(1)
+
V
-
+
V
-
Period
(1)