MIC5011 Micrel Semiconductor, MIC5011 Datasheet - Page 9

• Manufacturer Part Number: MIC5011
• Description: Minimum Parts High- or Low-Side MOSFET Driver
• Manufacturer: Micrel Semiconductor

MIC5011
Applications Information
diode limits the supply to 18V. When the MIC5011 is off,
power is supplied by a diode connected to a 15V supply.
The circuit of Figure 5 is put to good use as a barrier
between low voltage control circuitry and the 90V motor
supply.
Half-Bridge Motor Driver (Figure 8). Closed loop control of
motor speed requires a half-bridge driver. This topology
presents an extra challenge since the two output devices
should not cross conduct (shoot-through) when switching.
July 2000
15Vp-p, 20kHz
Squarewave
INPUT
PWM
10mA
Control Input
100nF
200V
15V
22k
2N3904
1N4003 (2)
1N4148
22k
1N4003
100k
(Continued)
4N35
220pF
1nF
15V
10k
33pF
Figure 8. Half-Bridge
100k
1k
1
2
3
4
Motor Driver
Source
V+
Input
Gnd
Figure 7. High-Voltage
MIC5011
Bootstrapped Driver
1
2
3
4
MPSA05
V+
Input
Source
Gnd
33k
+
10µF
MIC5011
Gate
Com
C2
C1
9
Cross conduction increases output device power dissipa-
tion. Speed is also important, since PWM control requires
the outputs to switch in the 2 to 20kHz range.
The circuit of Figure 8 utilizes fast configurations for both the
top- and bottom-side drivers. Delay networks at each input
provide a 2 to 3 s dead time effectively eliminating cross
conduction. Two of these circuits can be connected to-
gether to form an H-bridge for locked antiphase or sign/
magnitude control.
Gate
Com
8
7
6
5
C2
C1
1
2
3
4
100nF
V+
Input
Source
Gnd
8
7
6
5
MIC5011
1N5817
Gate
Com
C2
C1
+
1µF
8
7
6
5
1N4746
15V
1nF
5BPB56HAA100
1N4001 (2)
IRF541
IRF541
1/4 HP, 90V
M
+
12V,
10A Stalled
(GE)
100µF
90V
M
IRFP250
MIC5011
Micrel