PIC18LF4580ISOSQTP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC18LF4580ISOSQTP

28/40/44-Pin Enhanced Flash Microcontrollers with ECAN™ Technology, 10-Bit A/D and nanoWatt Technology

Microchip Technology 

PIC18F2480/2580/4480/4580

17.4.4 HALF-BRIDGE MODE

In the Half-Bridge Output mode, two pins are used as

outputs to drive push-pull loads. The PWM output

signal is output on the P1A pin, while the complemen-

tary PWM output signal is output on the P1B pin

(Figure 17-4). This mode can be used for half-bridge

applications, as shown in Figure 17-5, 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,

PDC<6:0>, 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 17.4.6

“Programmable Dead-Band Delay” for more details

of the dead-band delay operations.

Since the P1A and P1B outputs are multiplexed with

the PORTD<4> and PORTD<5> data latches, the

TRISD<4> and TRISD<5> bits must be cleared to

configure P1A and P1B as outputs.

FIGURE 17-4:

HALF-BRIDGE PWM

OUTPUT

Period

Period

P1A(2)

Duty Cycle

td

td

P1B(2)

(1)

(1)

(1)

td = Dead-Band Delay

Note 1: At this time, the TMR2 register is equal to the

PR2 register.

2: Output signals are shown as active-high.

FIGURE 17-5:

EXAMPLES OF HALF-BRIDGE OUTPUT MODE APPLICATIONS

V+

Standard Half-Bridge Circuit (“Push-Pull”)

PIC18F2X80/4X80

FET

Driver

+

P1A

V

-

FET

Driver

P1B

Load

+

V

-

Half-Bridge Output Driving a Full-Bridge Circuit

PIC18F2X80/4X80

P1A

P1B

FET

Driver

FET

Driver

V-

V+

Load

V-

FET

Driver

FET

Driver

DS39637D-page 182

© 2009 Microchip Technology Inc.

Share Link: