Datasheet
MCP1406/07
DS20002019C-page 12 2006-2016 Microchip Technology Inc.
4.0 APPLICATION INFORMATION
4.1 General Information
MOSFET drivers are high-speed, high current devices
which are intended to provide high peak currents to
charge the gate capacitance of external MOSFETs or
IGBTs. In high frequency switching power supplies, the
PWM controller may not have the drive capability to
directly drive the power MOSFET. A MOSFET driver
like the MCP1406/07 family can be used to provide
additional drive current capability.
4.2 MOSFET Driver Timing
The ability of a MOSFET driver to transition from a
fully-OFF state to a fully-ON state are characterized by
the drivers’ rise time (t
R
), fall time (t
F
) and propagation
delays (t
D1
and t
D2
). The MCP1406/07 family of
devices is able to make this transition very quickly.
Figure 4-1 and Figure 4-2 show the test circuits and
timing waveforms used to verify the MCP1406/07
timing.
FIGURE 4-1: Inverting Driver Timing
Waveform.
FIGURE 4-2: Non-Inverting Driver Timing
Waveform.
4.3 Decoupling Capacitors
Careful layout and decoupling capacitors are highly
recommended when using MOSFET drivers. Large
currents are required to charge and discharge
capacitive loads quickly. For example, 2.25A are
needed to charge a 2500 pF load with 18V in 20 ns.
To operate the MOSFET driver over a wide frequency
range with low supply impedance, a ceramic and a
low ESR film capacitor are recommended to be placed
in parallel between the driver V
DD
and the GND. A
1.0 µF low ESR film capacitor and a 0.1 µF
ceramic capacitor placed between pins 1, 8 and 4, 5
should be used. These capacitors should be placed
close to the driver to minimize circuit board parasitics
and provide a local source for the required current.
0.1 µF
+5V
10%
90%
10%
90%
10%
90%
18V
1µF
0V
0V
MCP1406
C
L
= 2500 pF
Input
Input
Output
t
D1
t
F
t
D2
Output
t
R
V
DD
= 18V
Ceramic
Input Signal: t
RISE
= t
FALL
= 10ns,
100 Hz, 0-5V Square Wave
90%
Input
t
D1
t
F
t
D2
Output
t
R
10%
10%
10%
+5V
18V
0V
0V
90%
90%
0.1 µF
1µF
MCP1407
C
L
= 2500 pF
Input Output
V
DD
= 18V
Ceramic
Input Signal: t
RISE
= t
FALL
= 10ns,
100 Hz, 0-5V Square Wave