m56786fp Mitsumi Electronics, Corp., m56786fp Datasheet - Page 5

• Manufacturer Part Number: m56786fp
• Description: Spindle Motor Actuator Driver
• Manufacturer: Mitsumi Electronics, Corp.

BRS=Open
Figure 3.
THE RELATIONSHIP WITH I/O CONTROL AND
THE BRAKING MODE
BRS=LOW
Figure 1.
BRS=Hi
Figure 2.
Forward Torque
Forward Torque
Forward Torque
0–+60mV
Current limit
0.8A/V
0.8A/V
0.8A/V
0
0
0
REVERSE BRAKING
0–-60mV
Reverse Torque
0–-60mV
Current limit
SHORT BRAKING
Current limit
Current limit
0.8A/V
0–-60mV
Reverse Torque
FREE RUN
EC-ECR
EC - ECR
EC - ECR
SPINDLE MOTOR AND 1CH ACTUATOR DRIVER
When the free run mode(BRS=open) is selected, the coil current
under the reverse torque control (EC-ECR>0) becomes zero and in
free run situation.
The braking mode is selected flexibly by using the BRS terminal.
The relationship between the EC-ECR (the difference between
EC<(control voltage> and ECR<reference voltage>) and the torque
is shown in Figure 1,2 and 3.
The current gain is 0.8A/V(at sensing resistor:0.5ohm) in forward
torque directions, and the dead zone is from0mV to 60mV.
When the reverse brake mode(BRS=Lo) is selected, the coil
current gain under the reverse torque control is the same with in
forward torque directions.
When the short brake mode(BRS=Hi) is selected, the coil current
under the reverse torque control depends on the back emf. and the
coil resistance.
MITSUBISHI <CONTROL / DRIVER IC>
M56786FP