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3

OMC506

The OMC506 is based on the Motorola MC33035 Brushless Motor Control I.C. This controller is used in

concert with the motorola MC33039 Closed Loop Brushless Motor Adapter I.C. to provide direct duty cycle

control of the motor speed. The OMC506 provides two quadrant speed control via an analog 0 to 5V signal

applied to the Vspeed ( pin22 ) input. The OMC506 is selected for 60/120 degree hall sensor spacing. The

commutation truth table for the OMC506 is shown in Table 1.

Controller

Block Diagram

RT/CT

V

MOTOR

CONTROL

F

OUT

6.2 V

REF

TACH IN

V

SPEED

+15 V

FWD/REV

OSC

C.S.+

C.S.-

BRAKE

ENABLE

REGULATOR

THREE

PHASE

REFRESH

R

SENSE

R

R

SENSE

C OUT

B OUT

A OUT

MOT

SA

SC

SB

DRIVER

A

DRIVER

B

DRIVER

C

TACHOMETER

COMPENSATION

LOOP

SHAPING

+15 V

V

OUT

OVER

TEMP

CKTRY