omc506 International Rectifier Corp., omc506 Datasheet - Page 4

• Manufacturer Part Number: omc506
• Description: Closed Loop Speed Controller For 3-phase Brushless Dc Motor Mp-3t Package
• Manufacturer: International Rectifier Corp.

OMC506
Notes:
1) Invalid Sensor Inputs; X= Don’t Care
2) V= Valid Sensor Input
Closed Loop Circuit
Additional amplifiers are used in the OMC506 to provide the necessary control loop compensation for extended
bandwidth. By extending the bandwidth of the direct duty cycle control system, torque pertubations can be
accounted for while regulating the speed of the motor. This allows the module to be used in relatively dynamic
systems as well as constant torque applications. Internally, the compensation circuitry used for control loop
shaping can be tuned to optimize the OMC506 for various applications.
The OMC506 provides directional, braking, and enable interfaces from the controller I.C. (pins 32, 24 and 25,
respectively). The module also allows the user to externally set the pulse width modulation (PWW) frequency
(pin21) as well as the pulse width from the Closed Loop Brushless Motor Adapter (pin 34). This allows a
common module to be used in many applications.
Motor commutation and speed control are derived from the Hall effect sensor signals provided from the motor.
The signals are provided as inputs to the OMC506 (pins 29, 30 and 31). The amplitude of the sensor signals
must be limited, by the user, to +6.2V to insure proper operation of the module.
Finally, the output from the Closed Loop Brushless Motor Adapter is provided as an output of the OMC506.
This signal has fixed amplitude and pre-set pulse width. The frequency is six times that of the motor. This
signal is integrated to produce a voltage proportional to motor speed.
Table 1 - Commutation Truth Table
SA
4
V
V
V
1
1
0
0
0
1
1
1
0
0
0
1
1
0
1
0
120
SB
V
V
V
0
1
1
1
0
0
0
1
1
1
0
0
1
0
1
0
°
SC
X
V
V
V
0
0
0
1
1
1
0
0
0
1
1
1
1
0
1
Inputs
F/R
X
X
X
X
X
X
X
1
1
1
1
1
1
0
0
0
0
0
0
Enable
X
X
X
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
Brake
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
A
OUT
1
0
0
0
1
0
1
1
0
0
0
0
0
-
-
-
-
-
-
B
OUT
1
1
0
0
0
1
1
0
0
0
0
-
-
-
-
-
-
-
-
C
OUT
Outputs
0
0
1
0
1
1
0
0
0
0
0
0
-
-
-
-
-
-
-
Fault
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
1
0
0
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Notes
1
1
2