MITSUBISHI <CONTROL / DRIVER IC> M51970L MOTOR SPEED CONTROL DESCRIPTION The M51970L is a semiconductor integrated circuit designed to control the motor rotating speed. Connection of the rotating speed detector (F-G detector) to the input keeps the motor rotating speed constant with high precision. Connection of an appropriate power transistor to the output controls a wide range of DC motors. PIN CONFIGURATION (TOP VIEW) FEATURES 1 Input 2 Stabilized voltage 3 (+)GND 4 (–)Power supply 5 Output 6 Current limit resistance 7 Integration capacitance 8 M51970L ●Wide range of supply voltage • • • • • • • • • • • • • 2.5 – 18V (-20 – +75˚C) ●Variation coefficient of supply voltage • • • • • • • • • • • ±0.1% standard (4 – 15V) ●Load variation coefficient • • • • • • • • • • • • • • • • • • • • • • • • • • ±0.1% standard ●Temperature coefficient of rotating speed • • • • • • • • • • • • • • ±10 ppm/˚C (standard) (-20 – +75˚C) ●The built-in over-shoot prevention circuit keeps the over-shoot low. ●DC drive system with minimum RFI Time constant Outline 8P5 APPLICATION Motor rotating control in the player, tape recorder, etc. RECOMMENDED OPERATING CONDITIONS Supply voltage range • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 2.5 – 18V Rated supply voltage • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 9V BLOCK DIAGRAM Input 2 (+)GND 4 (–)Power supply 5 Amplifier Time constant Integrated capacitance 1 8 Mono multivibrator Integrator Overshoot prevention circuit Stabilized power supply 3 Stabilized voltage Current limit circuit 7 Current limit resistance Current amplifier 6 Output MITSUBISHI <CONTROL / DRIVER IC> M51970L MOTOR SPEED CONTROL ABSOLUTE MAXIMUM RATINGS (Ta=25°C unless otherwise noted) Symbol Parameter Conditions Vcc I6 I3 Supply voltage Sink current into 6 pin Source current from 3 pin PdF Power dissipation KθF Topr Tstg Thermal derating Operating temperature Storage temperature With printed circuit board mounted (copper foil of 4.5 x 5.5 cm in area, thickness of 35µ, printed circuit board of 2.0 mm in thickness) Ratings Unit 18 40 -3 V mA mA 550 mW 5.5 -20 – +75 mW / °C °C °C -40 – +125 ELECTRICAL CHARACTERISTICS (Ta=25°C, Vcc=9V unless otherwise noted) Symbol VCC ICC VS VTH 2 RIN ISC 6 Tτ Reg-VCC Reg-L TCN Parameter Test conditions Supply voltage range Circuit current Stabilized output voltage Input threshold voltage Input impedance Output limit current One-shot pulse width Motor speed stability for Vcc Motor speed stability for load Motor speed stability for temperature Ta = -20 – +75˚C Except for output drive current RSC = 27Ω Rτ = 75kΩ, Cτ = 22,000pF VCC = 4 – 15V Ta = -20 – +75˚C Min. 2.5 3 1.8 -50 4.2 20 375 Limits Typ. – 4.5 2.0 0 7.9 27 395 ±0.1 ±0.1 ±10 TYPICAL CHARACTERISTICS (Ta=25°C unless otherwise noted) Thermal derating (Maximum rating) 1000 (1)IC only (2)With printed circuit board mounted (copper foil of 4.5 x 5.5 cm in area, thickness of 35µ, printed circuit board of 2.0 mm in thickness) Power dissipation Pd (mW) 900 800 700 600 (2) 500 (1) The data on the next page was measured with the following constants in the “Application Circuit Example” given below. R1=100kΩ, R2=30kΩ, CF1=1µF, CF2=4.7µF, RF=4.7kΩ, Rτ=75kΩ, Cτ=22,000pF, RSC=56Ω, number of tachogenerator poles; 10 poles. Motor speed - ambient temperature characteristics is measured with Rτ and Cτ put out of the temperature test chamber. 400 300 200 100 0 0 25 50 75 100 Ambient temperature Ta (°C) 125 Max. 18 8 2.2 50 12 35 415 Unit V mA V mV kΩ mA µs % % ppm/˚C MITSUBISHI <CONTROL / DRIVER IC> M51970L MOTOR SPEED CONTROL Rotating speed–Supply voltage characteristics 3060 No load Rotating speed N (rpm) Rotating speed N (rpm) 3060 Rotating speed–Motor torque characteristics 3055 3035 0 10 3055 3050 20 0 50 Supply voltage Vcc (V) 100 Torque T (g-cm) Rotating speed–Ambient temperature characteristics 3060 Vcc = 9V Vcc = 6V Circuit current–Supply voltage characteristics 5 Vcc = 9V No load Except for sink current to pin 6 Circuit current Icc (mA) Rotating speed N (rpm) 4 3055 3 2 1 3050 -20 0 20 40 60 0 80 0 Ambient temperature Ta (°C) 10 20 Supply voltage Vcc (V) APPLICATION CIRCUIT EXAMPLE Motor rotating speed control circuit + + RF CF1 R1 10µ + CF2 R2 4 Rτ 8 2 G VCC Tacho-generator 6 M51970L 3 M Cτ 1 5 7 RSC Motor MITSUBISHI <CONTROL / DRIVER IC> M51970L MOTOR SPEED CONTROL (Note 1) How to determine Rτ and Cτ This constant determines the motor rotating speed. If the motor rotating speed and the number of poles in the tacho-generator are assumed to be N and P, respectively, the following relational expression is generally established. Putting Rτ in the range of 10kΩ to 500kΩ, select the constant according to the required rotating speed. 1 1.17Rτ Cτ NP = Tacho-generator output frequency– Connection resistance characteristics of pin 1 5000 µF 2µ 02 F 7µ 04 1µ F 0. 500 pF 01 0. 0. 1000 700 00 47 τ= C 3000 2000 0. F Tacho-generator output frequency NP (Hz) 10000 300 200 100 10 20 30 50 70 100 200 300 500 1000 Connection resistance Rτ (kΩ) at pin 1 (Note 2) How to determine R SC According to the relation with maximum current ISC flowing to pin 6 , the following relational expression is generally established. Set ISC in such a way that the value cannot exceed the maximum rated value of the power dissipation of the M51970L when the supply voltage and temperature arrive at their maximum values. ISC = 0.7(V) RSC Maximum drive current at pin 6 – current limit resistance characteristics Maximum drive current at pin 6 50 40 30 20 10 0 0 20 40 60 80 100 120 140 160 180 200 Current limit resistance RSC (Ω) (Note 3) How to determine C F1, CF2 RF Select CF1 and CF2 RF according to the inertia of motor and required rising characteristics.