PIC16F684-E/P Microchip Technology Inc., PIC16F684-E/P Datasheet - Page 97

• Manufacturer Part Number: PIC16F684-E/P
• Description: 14 PIN, 3.5 KB FLASH, 128 RAM, 12 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F684-E/P

• A/d Inputs: 8-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 12
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 14-pin PDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• 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

11.4.6
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.
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 Section FIGURE 11-17:
“Example
illustration. The lower seven bits of the associated
PWM1CON register (Register 11-3) sets the delay
period in terms of microcontroller instruction cycles
(T
FIGURE 11-17:
© 2006 Microchip Technology Inc.
CY
Standard Half-Bridge Circuit (“Push-Pull”)
or 4 T
To
OSC
PROGRAMMABLE DEAD-BAND
DELAY MODE
of
).
avoid
Half-Bridge
EXAMPLE OF HALF-BRIDGE APPLICATIONS
this
potentially
Applications”
P1A
P1B
destructive
for
FET
Driver
FET
Driver
FIGURE 11-16:
P1A
P1B
td = Dead-Band Delay
Note 1: At this time, the TMR2 register is equal to the
(2)
(2)
V+
V-
2: Output signals are shown as active-high.
(1)
td
Pulse Width
PR2 register.
Load
Period
td
EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
+
V
-
+
V
-
PIC16F684
(1)
Period
DS41202D-page 95
(1)