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MIC5014-1 Datasheet, PDF (9/12 Pages) Micrel Semiconductor – Low-Cost High- or Low-Side MOSFET Driver Final Information
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MIC5014/5015
Micrel
High Side Driver With Load Protection (Figure 12) Al-
though the MIC5014/15 devices are reverse battery pro-
tected, the load and power FET are not, in a typical high side
configuration. In the event of a reverse battery condition, the
internal body diode of the power FET will be forward biased.
This allows the reversed supply access to the load.
The addition of a Schottky diode between the supply and the
FET eliminates this problem. The MBR2035CT was chosen
as it can withstand 20A continuous and 150A peak,
and should survive the rigors of an automotive environment.
The two diodes are paralleled to reduce switch loss (forward
voltage drop).
12V
10µF
Control Input
ON
OFF
MIC5014
1 V+
NC 8
2 Input
NC 7
3 Source NC 6
4 Gnd
Gate 5
MBR2035CT
IRF540
Figure 12: High Side Driver WIth Load Protection
Push-Pull Driver With No Cross-Conduction (Figure 13)
As the turn-off time of the MIC5014/15 devices is much faster
than the turn-on time, a simple push-pull driver with no cross
conduction can be made using one MIC5014 and one
MIC5015. The same control signal is applied to both inputs;
the MIC5014 turns on with the positive signal, and the
MIC5015 turns on when it swings low.
This scheme works with no additional components as the
relative time difference between the rise and fall times of the
MIC5014 is large. However, this does mean that there is
considerable deadtime (time when neither driver is turned on).
If this circuit is used to drive an inductive load, catch diodes
must be used on each half to provide an alternate path for the
kickback current that will flow during this deadtime.
This circuit is also a simple half H-bridge which can be driven
with a PWM signal on the input for SMPS or motor drive
applications in which high switching frequencies are not
desired.
12V
10µF
Control Input
MIC5014
1 V+
NC 8
2 Input
NC 7
3 Source NC 6
4 Gnd
Gate 5
IRFZ40
12V
MIC5015
1 V+
NC 8
2 Input
NC 7
3 Source NC 6
4 Gnd
Gate 5
VOUT
IRFZ40
1997
Figure 13: Push-Pull Driver
9
MIC5014/5015
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