Microchip Technology DM164130-2 Data Sheet
2010-2012 Microchip Technology Inc.
DS41414D-page 227
PIC16(L)F1946/47
23.4.1
HALF-BRIDGE MODE
In Half-Bridge mode, two pins are used as outputs to
drive push-pull loads. The PWM output signal is output
on the CCPx/PxA pin, while the complementary PWM
output signal is output on the PxB pin (see
drive push-pull loads. The PWM output signal is output
on the CCPx/PxA pin, while the complementary PWM
output signal is output on the PxB pin (see
). This mode can be used for Half-Bridge
, 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 PWMxCON 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
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 PWMxCON 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
for more details of the dead-band delay
operations.
Since the PxA and PxB outputs are multiplexed with the
PORT data latches, the associated TRIS bits must be
cleared to configure PxA and PxB as outputs.
PORT data latches, the associated TRIS bits must be
cleared to configure PxA and PxB as outputs.
FIGURE 23-8:
EXAMPLE OF
HALF-BRIDGE PWM
OUTPUT
HALF-BRIDGE PWM
OUTPUT
FIGURE 23-9:
EXAMPLE OF HALF-BRIDGE APPLICATIONS
Period
Pulse Width
td
td
(1)
PxA
(2)
PxB
(2)
td = Dead-Band Delay
Period
(1)
(1)
Note 1: At this time, the TMRx register is equal to the
PRx register.
2: Output signals are shown as active-high.
PxA
PxB
FET
Driver
FET
Driver
Load
+
-
+
-
FET
Driver
FET
Driver
V+
Load
FET
Driver
FET
Driver
PxA
PxB
Standard Half-Bridge Circuit (“Push-Pull”)
Half-Bridge Output Driving a Full-Bridge Circuit