Unipolar Driver ICs SI-7115B ■ Characteristics (Ta = 25°C) Parameter Type No. Absolute maximum rating Applied voltage Output current Junction temperature Vsurge(V) Io(A/ø) Tj(°C) SI-7115B 40 1.7 125 Electrical characteristics Operating Storage Supply Output Input ambient temperature voltage current current temperature Vcc(V) Io(A) Iin(mA) Top(°C) Tstg(°C) min typ max min max min max –20 to +80 –30 to +100 20 24 30 0.2 1.5 Phase switching signal input Oscillation frequency Output f (kHz) current min max (A/ø) 5.0 19 24 ON OFF Input Input Input voltage current voltage (V)min (mA)min (V)max 0.2 2.7 1.0 0.5 3.1 1.2 1.0 3.6 1.4 1.5 4.5 2.0 0.8 ■ Block diagram VCC Reference voltage Oscillator circuit Comparator amplifier Current controller M Rx Counter EMF canceller Output current fine adjustment resistor Excitation signal (4-phase) Current detection resistor Excitation signal amplifier SI-7115B ■ Equivalent circuit diagram ■ External connection diagram 18 6 9 7 10 VCC Q2 Q1 D4 D5 D1 D3 D2 D6 17 14 16 13 15 8 Q3 Q4 Q5 Q6 RS1 RS2 12 11 1 Excitation signal input Active High µF 2.2 10V + + – – Stepper motor 18 A B A B 8 13 10 15 1 + a – Rx b 17 6 SI-7115B 2 4 5 3 11 7 9 14 16 A A B B 12 5 Oscillator circuit 4 2 3 33 SI-7115B ■ External dimensions (Unit: mm) Plastic package Dimensions of SI-7115B pins 9.0±0.6 71.7±0.5 60.3±0.4 39.6±0.5 11.5±1 Type No. Lot No. 8.0 4.0 0.4 4 Aluminum plate φ 3.4 11.5±1 0.5 P=2.54 43.2 1 2 3 18 Application Note ■ Determining the output current Io (motor coil current) Fig. A SI-7115B External resistor vs. Output current 1.5 Output current IO (A/φ ) The output current Io can be set to any value by connecting an external resistor RX across pin 3 and all of pins 2, 4 and 5. Fig. A, B and C show the relationship between the external resistor and the output current, the supply voltage and the output current, and the output current and the temperature, respectively. Output current IO Output current IO RX 0.31 to 0.39 (A/ø) 200 (Ω) 0.95 to 1.05 (A/ø) 1.4 (kΩ) Condition VCC = 24V, Ta = 25°C 2-phase excitation Holding mode Motor: 23PM-C109 1.0 0.5 VCC 24(V) Rt 3.6(Ω) Motor : 23PM-C109 0 0 3 4 External resistor Rx (kΩ) Fig. B SI-711B Supply voltage vs. Output current Fig. C SI-7511B Output current vs. Temperature 1.5 Motor : 23PM-C109 Rx 1.5 Motor : 103G-775-1240 VCC = 24V Output current IO (A/φ ) Output current IO (A/φ ) 3.9kΩ 2kΩ 1.0 1kΩ 600Ω 300Ω 0.5 RX = 1.4kΩ 1.0 RX = 560Ω 0.5 100Ω 0 0 20 22 24 26 28 Supply voltage VCC (V) 34 30 0 0 20 40 60 80 100 Case (aluminium base plate) temperature Tc (°C) SI-7115B Application Note ■ Power down mode ■ Thermal design The SI-7115B can be operated in power down mode. The circuit is shown below. As shown in the figure, Power down circuit when the power down tran2 sistor is switched on, (Ry 4 is power down resistor) RY RX/RY becomes a current 5 fixing resistance and the R X SI-7115B current during power down mode can be obtained by 3 substituting this resistance to RX in the previous Fig. Power down Transistor TR A. In SI-7115B, the avalanche diode of the phase-switching transistor is operated in breakdown condition and the energy built up in the inductance of the motor coil is dissipated as heat of the transistor. Hence, when the motor rotates, the internal heat dissipation increases compared with when the motor is stopped. Therefore, the internal heat dissipation of 7115B can be computed from the data taken with actual load through the following procedures. (1) Vary the rotation speed of the motor within the actual operating range in a circuit under actual load conditions and measure the supply current ICC and the corresponding output current IO1 and IO2. Method for measuring current (circuit under actual load conditions) ■ Example of Frequency vs. Torque characteristics The following two graphs show the relationship between frequency (pps) and pull-out torque (kg - cm) of SI-7115B when used with two types of motor. VCC A ICC 15 Excitation signals SI-7115B Pull-out torque (kg-cm) 2.0 Torque characteristics 8 13 10 15 1 2-p 1-2 phase excitation A B A B has e ex µF 2.2 10V cita tion a + – Rx b Stepper motor IO1 A 17 A 6 IO2 SI-7115B 2 4 5 3 11 A 7 9 14 16 A B B 12 1.0 (2) Obtain the internal power dissipation Pdiss (4-phase) of 7115B through the following formula. Motor 103G–775–1240 VCC=24V IO = 1.0A/φ Pdiss = VCC•I CC – (IO12 + I O22)•R L The figure below shows the relationship between frequency (PPS) and I CC, Pdiss, and case temperature TC. 0 50 100 500 1000 5000 Frequency (PPS) SI-7115B Frequency vs. Supply current, Internal power dissipation and Case temperature (Example) SI-7115B Torque characteristics ICC ICC Supply current A Pdiss = VCC • ICC VCC 2 2 -RL (IO1 + IO2 ) TC Temperature of heatsink adjacent to SI-7115B 2-phase excitation 4.0 A SI 7115B I01 A I02 M Motor : 23 PM-C109 no load VCC = 24V IO = 1.0A/ φ 2-phase excitation Heatsink 100 x 100 x 2A Ta = 25°C ABAB 2p 1- 2 20 100 s ha PD (W) 10 Pdiss n tio ita xc 1 TC (°C) TC ICC (A) 3.0 ee 1.0 0 50 100 500 1000 Frequency (PPS) 5000 0 0 50 Case temperature Motor KP6M2-001 VCC=24V IO = 1.0A/φ Supply current 2.0 Internal heat dissipation Pull-out torque (kg-cm) 5.0 max ICC 0 0 500 1000 1500 Frequency (PPS) 35 SI-7115B Application Note (3) Obtain the heatsink area corresponding to the ambient temperature Ta from the derating curve. SI-7115B Derating curve 24 0× 20 20 0× 2( 3.4 0× °C 10 ) /W 15 16 0× 2 (3 .75 °C 10 /W 0× 1 12 ) 00 ×2 (4. 7°C /W ) 8 No he atsink 4 0 0 20 40 60 Ambient temperature Ta (°C) 36 (4) Verify that the temperature of the aluminum base plate of 7115B or adjacent heatsinks is below 85°C (equivalent to max. ambient temperature) when operating under actual load conditions. SI-7115B Aluminum heatsink Using silicone grease Unit : mm 10 Internal power dissipation PD (W) (2-phase) 28 80 SI-7200M, SI-7230M, SI-7115B, SI-7300A, SI-7330A, SI-7500A and SI-7502 Handling Precautions (Note: The SI-7502 is applicable for item (2) only.) For details, refer to the relevant product specifications. (1) Tightening torque: The torque to be applied in tightening screws when mounting the IC on a heatsink should be below 49N•m. (2) Solvent: Do not use the following solvents: Substances that Chlorine-based solvents : Trichloroethylene, dissolve the package Trichloroethane, etc. Aromatic hydrogen compounds : Benzene, Toluene, Xylene, etc. Ketone and Acetone group solvents Substances that weaken the package Gasoline, Benzine and Kerosene (3) Silicone grease: The silicone grease to be used between the aluminum base plate of the hybrid IC and the heatsink should be any of the following: • G-746 SHINETSU CHEMICAL INDUSTRIES CO., LTD. • YG6260 TOSHIBA SILICONE CO., LTD. • SC102 DOW CORNING TORAY SILICONE CO., LTD. Please pay sufficient attention in selecting silicone grease since oil in some grease may penetrate the product, which will result in an extremely short product life. Others • Resistance against radiation Resistance against radiation was not considered in the development of these ICs because it is assumed that they will be used in ordinary environment. 54