mc34151 ON Semiconductor, mc34151 Datasheet - Page 7

• Manufacturer Part Number: mc34151
• Description: High Speed Dual Mosfet Drivers
• Manufacturer: ON Semiconductor

imperative to prevent excessive output ringing and overshoot.
Do not attempt to construct the driver circuit on
wire−wrap or plug−in prototype boards. When driving
large capacitive loads, the printed circuit board must contain
a low inductance ground plane to minimize the voltage spikes
induced by the high ground ripple currents. All high current
loops should be kept as short as possible using heavy copper
runs to provide a low impedance high frequency path. For
The MC34151 greatly enhances the drive capabilities of common switching
regulators and CMOS/TTL logic devices.
High frequency printed circuit layout techniques are
Output Schottky diodes are recommended when driving inductive loads at
high frequencies. The diodes reduce the driver’s power dissipation by
preventing the output pins from being driven above V
TL494
TL594
or
Figure 19. Enhanced System Performance with
Figure 21. Direct Transformer Drive
Common Switching Regulators
3
4
2
+
+
47
+
V
+
CC
+
+
0.1
+
−
6
5.7V
7
3
5
1N5819
4 X
+
+
CC
and below ground.
+
+
LAYOUT CONSIDERATIONS
MC34151, MC33151
7
5
http://onsemi.com
V
in
7
optimum drive performance, it is recommended that the
initial circuit design contains dual power supply bypass
capacitors connected with short leads as close to the V
and ground as the layout will permit. Suggested capacitors are
a low inductance 0.1 mF ceramic in parallel with a 4.7 mF
tantalum. Additional bypass capacitors may be required
depending upon Drive Output loading and circuit layout.
critical and cannot be over emphasized.
Proper printed circuit board layout is extremely
Series gate resistor R
oscillations caused by the MOSFET input capacitance and any series
wiring inductance in the gate−source circuit. R
MOSFET switching speed. Schottky diode D
power dissipation due to excessive ringing, by preventing the output pin
from being driven below ground.
3
Figure 20. MOSFET Parasitic Oscillations
Figure 22. Isolated MOSFET Drive
+
g
may be needed to damp high frequency parasitic
+
5819
1N
1N5819
Boundary
Isolation
D
1
1
can reduce the driver’s
R
g
g
will decrease the
V
in
CC
pin