MC33033 Motorola, MC33033 Datasheet - Page 12

• Manufacturer Part Number: MC33033
• Description: BRUSHLESS DC MOTOR CONTROLLER
• Manufacturer: Motorola

Current Sense
Top Drive
Bottom Drive
Latch “Set”
Error Amp Out/
Capacitor C T
PWM Input
Input
Inputs
Outputs
Outputs
Transistor Q 1 is a common base stage used to level shift from V CC to the high
motor voltage, V M . The collector diode is required if V CC is present while V M
is low.
12
Decoder
Position
Rotor
Figure 22. High Voltage Interface with
Figure 20. PWM Timing Diagram
NPN Power Transistors
15
2
1
20
17
16
A T
B T
C T
V CC
Q 1
Q 2
Q 3
Q 4
Load
V M
MC33033
The NPN circuit is recommended for powering Hall or opto sensors, where the
output voltage temperature coefficient is not critical. The PNP circuit is slightly
more complex, but also more accurate. Neither circuit has current limiting.
Decoder
Position
Rotor
Figure 23. High Voltage Interface with
Figure 21. Reference Output Buffers
To Control Circuitry
and Sensor Power
V in
V in
U51A
U01A
MPS
MPS
N–Channel Power MOSFETs
Sensor
Power
6.25 V
5.6 V
MOTOROLA ANALOG IC DEVICE DATA
36
0.1
Circuitry
Control
6.25 V
To
14
14
7
7
15
2
1
20
17
16
C T
A T
B T
REF
REF
V CC = 12 V
4.7 k
1.0 k
1
2
Optocoupler
MOC8204
UVLO
UVLO
1.0 M
6
V Boost
1N4744
5
4
V M = 170 V
Load