mc33253 Freescale Semiconductor, Inc, mc33253 Datasheet - Page 11

• Manufacturer Part Number: mc33253
• Description: Full Bridge Pre-driver
• Manufacturer: Freescale Semiconductor, Inc

MC33253
increases, the average V
C
OP-Amp
provided by a shunt resistor, as shown in figure 13.
Therefore a gain of 10 sets the maximum drop voltage on the sensing resistance at 500mV.
C
C
Capacitors typical values
cp_out
cp_out
LR_OUT
The smaller C
As shown in figure 11, at high side MOSFET turn on, V
Q
The following figure is the simplified C
f
C
In most working cases the following typical values are advised for a good charge pump performing:
C
These values give a typical 100mV voltage ripple on V
The built-in A.O.P. available in the MC33253 allows to get a voltage image of the H-bridge current. This voltage can be
Typically shunt resistivity is dimensioned as low as possible (25mOhm/10A). The maximum A.O.P output voltage is 5V.
pwm
LR_OUT
cp
g
: Power MosFET Gate Charge
=33nF, C
value as following :
: working switching frequency
provides peak current needed by the low side MOSFET turn on. V
cp_out
cp
average V
value is, the smaller V
=470nF and C
cp_out
V
I
Cp_out
Cp_out
Cp_out
level decreases. For most of the applications a typical value of 33nF is recommended.
Figure 11. Simplified C
Freescale Semiconductor, Inc.
LR_OUT
Oscillator
in high
state
For More Information On This Product,
f=330kHz
cp_out
=470nF.
cp_out
Oscillator
in low
state
current and voltage waveforms.
Go to: www.freescale.com
value is. Moreover, for a same C
∆
∆
V
Current
V
cp_out
Peak
Ccp
LR
cp_out
cp_out
MOTOROLA
MC33253
_
_
out
out
Current and Voltage Waveforms
voltage decreases. This decrease can be calculated according to
and V
=
=
C
C
LR
Q
Q
cp
LR_OUT
_
_
g
g
out
out
∆
V
Ccp
with Q
_
LR_OUT
out
High Side
turn on
f
PWM
g
=50nC.
cp
decreasing is as follow:
value, when the switching frequency
rev3.0 - 11/15