MITSUBISHI <CONTROL / DRIVER IC>
M51971L/FP
MOTOR SPEED CONTROL
DESCRIPTION
The M51971 is a semiconductor integrated circuit designed to
control the motor rotating speed.
The built-in FG amplifier with high gain enables to use a wide
range of rotating speed detector (FG detector).
Use of less external parts enables DC motors to be controlled with
high precision.
PIN CONFIGURATION (TOP VIEW)
Non-inverted input
Inverted input
Amplifier output
1
2
3
4
FEATURES
qWide
range of supply voltage
• • • • • • • • • • • • • • • • • • • • • • • • • • • • •
4 – 17.5V
qVariation
coefficient of supply voltage
• • • • •
±0.005%/V
(standard)
qLoad
variation coefficient
• • • • •
±0.01%
(standard, full load range)
qTemperature
coefficient of rotating speed
• • • •
7ppm/˚C (standard)
qBuilt-in
high performance FG amplifier
Schmitt input
Time constant
Stabilized voltage
GND
Integration capacitance
Output
M51971L
5
6
7
8
9
APPLICATION
Motor rotating speed control in floppy disk driver, player, tape
recorder, car stereo, etc.
Power supply 10
Outline 10P5
RECOMMENDED OPERATING CONDITIONS
Supply voltage range
• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •
4 – 17.5V
Rated supply voltage
• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •
9V
Input voltage range at pin
1
• • • • • • • • • • • • • • • • •
-0.4 – Vcc Note 1
Input voltage range at pin
4
• • • • • • • • • • • • • • • • • • • • • • • • • •
-0.4 – Vcc
Highest setup tacho-generator frequency
• • • • • • • • • • • • • • • •
2.5kHz
Minimum trigger pulse width (input pulse at pin
4
)
• • • • • • • • • •
40µs Note 2
Note 1: The linear operation range is -0.4 to +0.4V.
Note 2: This condition applies to both periods: from pulse rising to
pulse falling and pulse falling to pulse rising.
Non-inverted input
Inverted input
Amplifier output
Schmitt input
Time constant
1
10 Power supply
M51971FP
2
3
4
5
9
8
7
6
Output
Integration capacitance
GND
Stabilized voltage
Outline 10P2-C
BLOCK DIAGRAM
Amplifier Schmitt
output
intput
3
Operational
amplifier
4
Schmitt
comparator
Timer
Constant
current
control
Over-shoot
prevention
circuit
Time constant
5
Integration
capacitance
8
Buffer
amplifier
9 Output
V
LS
Non-inverted input
Inverted input
1
1.9V
2
V
LS
1.9V
Power supply 10
Stabilized supply
voltage
7
GND
6
Stabilized
voltage
MITSUBISHI [ MITSUBISHI ELECTRIC SEMICONDUCTOR ]
