PIC16F887-I/PT Microchip Technology Inc., PIC16F887-I/PT Datasheet - Page 137

• Manufacturer Part Number: PIC16F887-I/PT
• Description: MCU, 8-Bit, 8KW Flash, 368 RAM, 36 I/O, TQFP-44
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F887-I/PT

• A/d Inputs: 14-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Frequency: 20 MHz
• Input Output: 35
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 44-pin TFQP
• Programmable Memory: 14K Bytes
• Ram Size: 368 Bytes
• Resistance, Drain To Source On: Bytes
• Serial Interface: MSSP or EUSART
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

11.6.1
In Half-Bridge mode, two pins are used as outputs to
drive push-pull loads. The PWM output signal is output
on the CCPx/P1A pin, while the complementary PWM
output signal is output on the P1B pin (see
Figure 11-9). This mode can be used for Half-Bridge
applications, as shown in Figure 11-9, or for Full-Bridge
applications, where four power switches are being
modulated with two PWM signals.
In Half-Bridge mode, the programmable dead-band delay
can be used to prevent shoot-through current in
Half-Bridge power devices. The value of the PDC<6:0>
bits of the PWM1CON register 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 11.6.6 “Programmable Dead-Band Delay
Mode” for more details of the dead-band delay
operations.
FIGURE 11-9:
© 2007 Microchip Technology Inc.
Standard Half-Bridge Circuit (“Push-Pull”)
Half-Bridge Output Driving a Full-Bridge Circuit
HALF-BRIDGE MODE
EXAMPLE OF HALF-BRIDGE APPLICATIONS
P1A
P1B
P1A
P1B
FET
Driver
FET
Driver
PIC16F882/883/884/886/887
Preliminary
FET
Driver
FET
Driver
Since the P1A and P1B outputs are multiplexed with
the PORT data latches, the associated TRIS bits must
be cleared to configure P1A and P1B as outputs.
FIGURE 11-8:
P1A
P1B
td = Dead-Band Delay
Note 1: At this time, the TMR2 register is equal to the
Load
V+
(2)
(2)
2: Output signals are shown as active-high.
(1)
PR2 register.
Pulse Width
td
Load
Period
td
FET
Driver
FET
Driver
EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
+
-
+
-
(1)
DS41291D-page 135
Period
(1)