m51971 Mitsumi Electronics, Corp., m51971 Datasheet - Page 10

• Manufacturer Part Number: m51971
• Description: Motor Speed Control
• Manufacturer: Mitsumi Electronics, Corp.

Frequency input
VI. To switch the set rotating speed in stages with
VII. Limiting output current at pin
IX. Frequency comparator
Note: The selected Hysteresis of the Schmitt circuit must be more than or
control signals
IC from heating
I
(See the Electrical Characteristics and Typical Characteristics.)
equal to the ripple current at pin
9
max
M51971FP
7
M51971L
M51971FP
=
M51971L
R
4
V
7
9
9
5
C
+ R
M51971FP
max
F1
M51971L
R
V
SC
10
8
CC
C
: V
6
6
5
7
9
6
8
R
C
max
F
F2
R
10
C
F
~ ~
R
5
3.2V, R
8
1
(to prevent chattering).
9
R
Control
signal 1
C
R’
2
R
9
SC
9
~ ~
100
9
Schmitt circuit
R
to prevent the
C
signal 2
Control
3
M
R’ > 2R
Q
1
V
CC
Output
VIII. To limit drive current to the motor
1)
2) To reduce power loss due to a current limiting resistance
Input/output transmission characteristics
f
f
TH1
TH2
~ ~
~ ~
7
1.09 x R // R’ x C x In
1.20 x R
7
M51971FP
M51971L
MITSUBISHI <CONTROL / DRIVER IC>
M51971FP
I
M51971L
M
5
max
C
1
F1
5
R
~ ~
C
•
= (V
8
C
F1
C
R
(R
I
M
6
8
BE2
C
Input frequency
max
f
0.7V x R
1
2
TH2
+ R
R
– V
6
C
F
MOTOR SPEED CONTROL
=
F2
3
10
R
BE1
)
C
V
•
F
R
F2
BE2
R
10
SC
2
3(R + R’ )
R’ – 2R
x
SC
f
TH1
R
~ ~
9
2
R
M51971L/FP
+ R
R
3
0.7V
R
9
1
SC
3
R
) / R
200
1
Q
SC
200
2
Q
2
R
R
M
2
Q
3
1
M
R
Q
SC
I
1
M
R
V
SC
CC
I
M
V
CC