m56786fp Mitsumi Electronics, Corp., m56786fp Datasheet - Page 7

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

HALL AMPLIFIER INPUT AND COMMUTATION
The relationship between the hall amplifier inputs voltage and the
motor current outputs is shown in Figure 4.
Figure 4.
BRAKING MODE SELECT FUNCTION
Figure 5.
FG FUNCTION
Figure 6.
SLEEP MODE FUNCTION and MUTE FUNCTION
Figure 7.
L,OPEN
L,OPEN
LOW or OPEN
S/S
H
H
NX1 pulse
S/S
current
Output
FG pulse select (FGSpin)
inputs
Hall
OPEN
HIGH
LOW
Braking mode select [BRS] pin
L,OPEN
L,OPEN
MUTE
H
H
U
V
M U T E
Hall bias
Hw+
Spindle
NX3 pulse
OFF
OFF
ON
ON
W
HIGH
REVERSE BRAKE
U
SHORT BRAKE
FREE RUN
CIRCUIT
Actuator
Hv+
OFF
OFF
ON
ON
V
W
CIRCUIT
Hu+
BIAS
OFF
ON
ON
ON
U
V
CIRCUIT
TSD
OFF
W
ON
ON
ON
SOURSE
SINK
SPINDLE MOTOR AND 1CH ACTUATOR DRIVER
It is possible to select three kinds of mode [the reverse braking, the
short braking and the free run] in reverse torque by logic control
using the BRS terminal.
Figure 5 shows the function table of the braking mode select.
It is the reverse braking when BRS is LOW, the short braking when
BRS is HIGH and the free run when BRS is OPEN.
It is possible for user to switch the output pulse numeric by external
logic control using FG pulse select terminal [FGS].
Figure 6 shows the FG pulse select function.
The FG pin outputs the square pulse signal synchronizing with the
hall inputs [Hv+ and Hv-] timming when FGS=LOW or OPEN.
When FGS=HIGH, it outputs the square pulse signal of 3 times.
The FG pin is pulled-up to V
10Kohm].
This IC has the S/S terminal (S/S) for ON/OFF of the Spindle motor
drive and the MUTE terminal (MUTE) for ON/OFF of the actuator
drive.
It is possible to control ON / OFF of each circuit (SPM, Actuator) by
external logic inputs.
The figure 7 shows its function.
In case of both S/S and MUTE is LOW or OPEN, the bias of all
circuit becomes OFF[Current is zero].
Therefore, this mode is available in order to reduce the power
dissipation when the waiting mode.
Hall elements
W
MITSUBISHI <CONTROL / DRIVER IC>
V
W
V
U
U
FORWARD
EC<ECR
U
V
CC
W
1 by an internal resistor [typ.
W
V
U
M56786FP
Outer loator
REVERSE
EC>ECR