PIC16F1947-I/PT Microchip Technology Inc., PIC16F1947-I/PT Datasheet - Page 232

• Manufacturer Part Number: PIC16F1947-I/PT
• Description: 64 TQFP 10x10x1mm TRAY28KB Flash, 1KB RAM, 256B EEPROM, LCD, 1.8-5.5V
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F1947-I/PT

• A/d Inputs: 17-Channel, 10-Bit
• Comparators: 3
• Cpu Speed: 8 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 54
• Interface: CAN/I2C/SPI/UART/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 64-pin TQFP
• Programmable Memory: 28K Bytes
• Ram Size: 1K Bytes
• Speed: 32 MHz
• Timers: 4-8-bit, 1-16-bit
• Voltage, Range: 1.8-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC16F/LF1946/47
23.4.5
In Half-Bridge applications where all power switches
are modulated at the PWM frequency, the power
switches normally require more time to turn off than to
turn on. If both the upper and lower power switches are
switched at the same time (one turned on, and the
other turned off), both switches may be on for a short
period of time until one switch completely turns off.
During this brief interval, a very high current
(shoot-through current) will flow through both power
switches, shorting the bridge supply. To avoid this
potentially destructive shoot-through current from
flowing during switching, turning on either of the power
switches is normally delayed to allow the other switch
to completely turn off.
In Half-Bridge mode, a digitally programmable
dead-band delay is available to avoid shoot-through
current from destroying the bridge power switches. The
delay occurs at the signal transition from the non-active
state to the active state. See
illustration. The lower seven bits of the associated
PWMxCON register
period in terms of microcontroller instruction cycles
(T
FIGURE 23-17:
DS41414B-page 232
CY
Standard Half-Bridge Circuit (“Push-Pull”)
or 4 T
OSC
PROGRAMMABLE DEAD-BAND
DELAY MODE
).
(Register
EXAMPLE OF HALF-BRIDGE APPLICATIONS
23-5) sets the delay
Figure 23-16
PxA
PxB
Preliminary
for
FET
Driver
FET
Driver
FIGURE 23-16:
PxA
PxB
td = Dead-Band Delay
Note 1: At this time, the TMRx register is equal to the
(2)
(2)
V+
V-
(1)
2: Output signals are shown as active-high.
td
Pulse Width
PRx register.
Load
Period
td
EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
 2010 Microchip Technology Inc.
+
V
-
+
V
-
(1)
Period
(1)