M56784 Mitsubishi, M56784 Datasheet - Page 5

• Manufacturer Part Number: M56784
• Description: SPINDLE MOTOR DRIVER
• Manufacturer: Mitsubishi

HALL AMPLIFIER INPUT AND COMMUTATION
The relationship between the hall amplifier inputs voltage and the motor current outputs is shown in Figure 2.
Figure 2.
HALL AMPLIFIER INPUT SENSITIVITY SELECT
Figure 3.
SLEEP MODE FUNCTION
Figure 4.
LOW or OPEN
The hall amp
minimum input
voltage is
50mVp-p.
Hall
inputs
Output
current
Hall-Bias off
OPEN or HIGH
120 degree
soft switching
Motor Stop
Bias off
START / STOP (
U
V
MODE4
Hw+
120 degree switching
** Io current
Hall-Bias on
changes sharply.
W
41
Motor on
Bias on
The hall amp
minimum input
voltage is
35mVp-p.
HIGH
U
pin)
Hv+
GND
V
W
Hu+
U
V
W
SOURSE
SINK
Figure 3 shows the hall amplifier input sensitivity select function.
You are able to select a sensitivity of a hall amplifier out of two
levels which is suitable for the hall elements type.
If the output minimum level of the hall elements is lower than
50mVp-p, please connect the MODE4 pin to external GND. In this
case, the output current changes shaply. If the output minimum
level of the hall elements is higher than 50mVp-p, please make the
MODE4 pin open, then the output current is commutated softly.
We recommend that the output level of the hall elements be set
between 80mVp-p and 120mVp-p, and the MODE4 pin is an open.
Figure 4 shows the sleep mode function. If the
be open or low, the motor drive outputs have high impedance and
the motor stops. Then, the IC bias current will be a slight current
(please refer to the electrical characteristics), and the hall bias
output will be cut off. When the
will work.
Hall elements
W
V
MITSUBISHI <CONTROL / DRIVER IC>
W
V
U
U
FORWARD
EC < ECR
V
U
SPINDLE MOTOR DRIVER
W
41
pin input is high, all the circuits
W
V
U
M56784FP
41
Outer loator
pin [S/S] is set to
REVERSE
EC > ECR