Ordering number : EN7465A Thick-Film Hybrid IC STK672-220-E Unipolar Constant-Current Chopper Two-Phase Stepping Motor Driver Output Current 2.8A Overview The STK672-220-E is two-phase stepping motor driver hybrid IC (HIC) that features further miniaturization and improved input logic flexibility as compared to the STK6713 series products. Applications • The STK672-220-E is optimal for use as a stepping motor driver in printers, copiers, XY plotters, and similar equipment. Features • Built-in common-mode input protection circuit. • The input signal logic lines are provided as active-high and active-low pairs, and thus support switching the motor wiring. • Built-in current detection resistor for reduced external component mounting area on the printed circuit board. • Inhibit pin (cuts off the motor current) • Wide motor operating range (10 to 45V) Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to "standard application", intended for the use as general electronics equipment (home appliances, AV equipment, communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee thereof. If you should intend to use our products for applications outside the standard applications of our customer who is considering such use and/or outside the scope of our intended standard applications, please consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our customer shall be solely responsible for the use. Specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer' s products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer' s products or equipment. 71608HKIM/61504TN (OT) No.7465-1/10 STK672-220-E Specifications Absolute Maximum Ratings at Tc = 25°C Parameter Symbol Conditions Ratings Unit Maximum supply voltage 1 VCC1 max No signal 52 V Maximum supply voltage 2 VCC2 max V No signal -0.3 to +7.0 Input voltage VIN max Logic input pins -0.3 to +7.0 V Output current IOH max 0.5s, 1 pulse, when VCC1 is applied 3.3 A Allowable power dissipation Pd max With an arbitrarily large heat sink. Per MOSFET 9 W Operating substrate temperature Tc max 105 °C Junction temperature Tj max 150 °C Storage temperature Tstg -40 to +125 °C Allowable Operating Ranges at Ta = 25°C Parameter Symbol Conditions Supply voltage 1 VCC1 With signals applied Supply voltage 2 VCC2 With signals applied Input voltage Ratings VIH Unit 10 to 45 V 5.0 ± 5% V 0 to VCC2 V Phase driver withstand voltage VDSS ID = 1mA (Tc = 25°C) 100 V Output current 1 IOH1 CLK ≥ 200Hz, Tc = 105°C 2.8 A Output current 2 IOH2 CLK ≥ 200Hz, Tc = 80°C 3 A Electrical Characteristics at Tc = 25°C, VCC1 = 24V, VCC2 = 5V Parameters Symbols Rating Conditions min Control supply current ICCO With all inputs at the VCC2 level Output average current Ioave With R/L = 3.5Ω/3.8mH in each phase typ 0.549 unit max 3.3 10 0.610 0.671 mA A 1.1 1.8 V 0.7 1.2 V FET diode forward voltage Vdf If = 1.0A Output saturation voltage Vsat RL = 12Ω Vref input voltage VrH Pin 12 Vref input bias current IIB With pin 12 at 1V VIH HIC pins 6, 7, 8, 9, and 11 VIL HIC pins 6, 7, 8, 9, and 11 IIH HIC pins 6, 7, 8, 9, and 11, VIN = VCC2 310 μA IIL HIC pins 6, 7, 8, 9, and 11, VIN = 0V 2.5 μA 0 50 3.5 V 500 nA [Control Input Pins] Input voltage Input current 3.5 V 0.7 V Note: A fixed-voltage power supply must be used. Package Dimensions unit:mm (typ) 4167 46.6 8.5 1 2.0 (9.6) 11 2=22 12 0.5 1.0 4.0 12.7 3.6 25.5 41.2 0.4 2.9 No.7465-2/10 STK672-220-E Internal Block Diagram 5 φAB φA 8 9 4 Vref 12 Off Time setting φBB φB 6 7 VCC2 10 3 2 Off Time setting Inhibit 11 PG 1 SUB Sample Application Circuit VCC2=5V 10 φA 9 2 φAB 8 3 φB 7 4 φBB 6 5 Inhibit 11 Stepping motor STK672-220-E Ro1 Co2=10μF At least VCC1=24V Co1=220μF + 12 + Ro2 1 S.GND P.GND ITF02299 • The Co1 ground lead must be connected as close as possible to pin 1 on the hybrid IC. • HC type CMOS levels are recommended as the input specifications for pins 6 to 9. • In case of TTL input, connect a pull-up resistor. (Recommended value: 2kΩ) • Excitation control input specifications Corresponding output pin Corresponding excitation control input signal Active: High Active: Low 2 pin φB φBB 3 pin φBB φB 4 pin φA φAB 5 pin φAB φA No.7465-3/10 STK672-220-E Phase signal: Active low input 2-phase excitation Clock 1-2 phase excitation Clock Pin 6 Phase signal BB Pin 6 Phase signal BB Pin 7 Phase signal B Pin 7 Phase signal B Pin 8 Phase signal AB Pin 8 Phase signal AB Pin 9 Phase signal A Pin 9 Phase signal A Pin 2 MOSFET gate signal Pin 2 MOSFET gate signal Pin 3 MOSFET gate signal Pin 3 MOSFET gate signal Pin 4 MOSFET gate signal Pin 4 MOSFET gate signal Pin 5 MOSFET gate signal Pin 5 MOSFET gate signal Phase signal: Active high input 2-phase excitation 1-2 phase excitation Clock Clock Pin 6 Phase signal BB Pin 6 Phase signal BB Pin 7 Phase signal B Pin 7 Phase signal B Pin 8 Phase signal AB Pin 8 Phase signal AB Pin 9 Phase signal A Pin 9 Phase signal A Pin 2 MOSFET gate signal Pin 2 MOSFET gate signal Pin 3 MOSFET gate signal Pin 3 MOSFET gate signal Pin 4 MOSFET gate signal Pin 4 MOSFET gate signal Pin 5 MOSFET gate signal Pin 5 MOSFET gate signal No.7465-4/10 STK672-220-E Setting the Motor Current Peak Value (IOH) IOH ≈ Vref ÷ Rs Vref: STK672-220-E pin 12 input voltage Rs: STK672-220-E internal current detection resistor (0.17Ω ±2%) IOH 0 Model of the Motor Current Flowing into the Driver IC (pins 2, 3, 4, and 5) Vref = (Ro2 ÷ (Ro1 + Ro2)) × VCC2 VCC2 = 5V Current Switching Techniques Due to the input bias current (IIB) specifications, Ro1 must be under 100kΩ. The figures below present sample circuits that temporarily switch the motor current when, for example a held motor stops. We recommend using the circuit structure in the figure at the left to minimize as much as possible the effects of the saturation voltage of the reference voltage switching transistor. 5V 5V Ro1 Vref Ro1 Ro3 Vref Ro2 Ro3 Switching Circuit 1 Ro2 Switching Circuit 2 Input Pin Circuits Input pin Pin 6, 7, 8, and 9 Circuit type X phase (XB phase) MOSFET gate signal XB phase PWM signal 5V 10kΩ To XB phase 5V The 5V/GND switch shows how toff time setting operates in the internal block diagram on page 3. When switched to GND, pull-down with an input resistance of 20kΩ is formed. 10kΩ Pin 11 10kΩ Inhibit 10kΩ GND Pin 12 VCC2 CR input Vref To one of the comparator GND No.7465-5/10 STK672-220-E Thermal Design The size of the heat sink required for the STK672-220-E depends on the output current IOH (A), the electrical characteristics of the motor, the excitation mode, and the basic drive frequency. The thermal resistance (θc-a) of the required heat sink can be determined from the following formula. θc - a = Tc max - Ta Pd (°C/W) Tc max: The STK672-220-E substrate temperature (°C) Ta: The STK672-220-E ambient temperature (°C) Pd: The average internal power dissipation in the STK672-220-E (W) For example, the required area for a heat sink made from 2mm thick aluminum can be determined from the graph at the right below. Note that the ambient temperature is greatly influenced by the ventilation and air flow patterns within the application. This means that the size of the heat sink must be determined with care so that the STK672-220-E back surface (aluminum substrate) temperature Tc in the mounted state never exceeds, under any conditions that might occur, the temperature Tc = 105°C. θc-a - Pd θc-a - S 16 θc-a= Tc max--Ta (°C/W) Pd 12 8 40°C 50°C 60°C 4 0 Heat sink thermal resistance, θc-a - °C/W 100 No Fin 23.0[°C/W] Tc max=105°C d ee nt t re ra ien tu ua b ra G am pe m te Heat sink thermal resistance, θc-a - °C/W 20 No Fin 23.0[°C/W] Mounted vertically Convection cooling 7 5 3 2 2mm 10 thic k (W i th 7 5 Al p late a fl (w i th n o at b lack 3 surf ace f surf ace fi 2 inis h) nish ) 1.0 0 2 4 6 8 10 12 14 16 IC internal average power dissipation, Pd - W 18 20 10 2 3 5 7 100 2 3 5 Heat sink area, S - cm2 ITF01880 7 1000 ITF01881 STK672-220-E Average Internal Power Dissipation Pd Of the devices that contribute to the STK672-220-E average internal power supply, the devices with the largest power dissipation are the current control devices, the diodes that handle the regenerative current, the current detection resistor, and the predriver circuit. The following presents formulas for calculating the power dissipation for the different excitation (drive) modes. 2 phase excitation mode Pd2EX = (Vsat + Vdf) × 0.5 × CLOCK × IOH × t2 + 0.5 × CLOCK × IOH × (Vsat × t1 + Vdf × t3) 1-2 phase excitation mode Pd1-2EX = (Vsat + Vdf) × 0.25 × CLOCK × IOH × t2 + 0.25 × CLOCK × IOH × (Vsat × t1 + Vdf × t3) Motor hold mode PdHOLDEX = (Vsat + Vdf) × IOH Vsat: Ron voltage drop + shunt resistor combined voltage Vdf: FET internal diode + shunt resistor combined voltage CLOCK: Input clock (shows clock in the timing charts on page 4) IOH 0A t1 t2 t3 Figure 1 Motor COM current waveform model No.7465-6/10 STK672-220-E t1: The time until the winding current reaches its rated current (IOH) t2: The time in the constant-current control (PWM) region t3: The time from the point a phase signal is cut until the back EMF current is dissipated. t1 = (–L/(R + 0.4)) In (1 – ((R + 0.4)/VCC1) × IOH) t3 = (–L/R) In ((VCC1 + 0.4) / (IOH × R + VCC1 + 0.4)) VCC1: Motor supply voltage (V) L: Motor inductance (H) R: Motor winding resistance (Ω) IOH: Set motor output current wave height (A) The constant-current control time t2, and the time T (= t1 + t2 + t3) that the phase signal is on in each excitation mode are as follows. 2 phase excitation mode: t2 = (2/Clock) – (t1 + t3) 1-2 phase excitation mode: t2 = (3/Clock) – t1 Determine the values for Vsat and Vdf by substitution using the graphs for Vsat vs IOH and Vdf vs IOH for the set current value for IOH. Then judge whether or not a heat sink is required from the determined average power dissipation for the STK672-220-E by comparison with the ΔTc vs. Pd graph. Note that it is necessary to check the temperature rise in the actual application system case, since the STK672-220-E substrate temperature Tc changes with the air convection conditions around the STK672-220-E when a heat sink without fins is used. Vsat - IO 1.4 2.0 1.5 °C 05 C =1 25° Tc 1.0 1.2 C 25° Tc= 1.0 °C 105 0.8 0.6 0.4 0.5 0.2 0 0 0 1 2 3 4 Motor current, IO - A 0 0.5 1.0 Input pin current, IIH, IIL - μA 0.5 0.4 0.3 0.2 0.1 1.5 2.0 2.5 3.0 3.5 Motor current, If - A ITF02300 Vref - IOH 0.6 Reference voltage, Vref - V Vdf - If 1.6 Forward voltage, Vdf - V Output saturation voltage, Vsat - V 2.5 4.0 ITF02301 IIH - Tc 1000 7 5 3 2 IIH 100 7 5 3 2 10 7 5 3 2 IIL 1.0 7 5 3 2 0.1 0 0 0.5 1.0 1.5 2.0 2.5 Motor current, IOH - A 3.0 3.5 ITF02302 0 20 40 60 80 Substrate temperature, Tc - °C 100 120 ITF02303 No.7465-7/10 STK672-220-E IOH - Tc Motor current, IOH - A 2.0 1.5 1.0 0.5 0 20 40 60 80 100 Substrate temperature, Tc - °C 70 60 50 40 30 20 10 120 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Hybrid IC internal power dissipation, Pd - W ITF02304 ΔTc - CLK 80 ITF02305 IOH - Tc 3.5 IOH=1.8A 1-2ex Motor running 3.0 60 IOH=1.5A 2ex Motor current, IOH - A Substrate temperature rise, ΔTc - °C 80 0 0 70 ΔTc - Pd 90 Substrate temperature rise, ΔTc - °C 2.5 50 40 30 20 10 Motor voltage: 24V Vertical, independent, heat sink without fins Natural convection Motor: R=1.4Ω, L=1.6mH 0 100 2 3 5 7 2.5 Motor hold state current 2.0 1.5 1.0 1000 2 3 Input frequency, CLK - Hz 5 7 10000 ITF02306 0 10 20 30 40 50 60 70 80 Substrate temperature, Tc - °C 90 100 110 ITF02307 STK672-220-E Allowable Avalanche Energy Value [Allowable Range in Avalanche Mode] When driving a 2-phase stepping motor with constant current chopping using an STK672-2** Series hybrid IC, the waveforms shown in Figure 1 below result for the output current, ID, and voltage, VDS. VDSS: Voltage during avalanche operations VDS IOH: Motor current peak value IAVL: Current during avalanche operations ID tAVL: Time of avalanche operations ITF02557 Figure 1 Output Current, ID, and Voltage, VDS, Waveforms 1 of the STK672-2** Series when Driving a 2-Phase Stepping Motor with Constant Current Chopping No.7465-8/10 STK672-220-E When operations of the MOSFET built into STK672-2** Series ICs is turned off for constant current chopping, the ID signal falls like the waveform shown in the figure above. At this time, the output voltage, VDS, suddenly rises due to electromagnetic induction generated by the motor coil. In the case of voltage that rises suddenly, voltage is restricted by the MOSFET VDSS. Voltage restriction by VDSS results in a MOSFET avalanche. During avalanche operations, ID flows and the instantaneous energy at this time, EAVL1, is represented by Equation (1). EAVL1=VDSS×IAVL×0.5×tAVL ------------------------------------------- (1) VDSS: V units, IAVL: A units, tAVL: sec units The coefficient 0.5 in Equation (1) is a constant required to convert the IAVL triangle wave to a square wave. During STK672-2** Series operations, the waveforms in the figure above repeat due to the constant current chopping operation. The allowable avalanche energy, EAVL, is therefore represented by Equation (2) used to find the average power loss, PAVL, during avalanche mode multiplied by the chopping frequency in Equation (1). PAVL=VDSS×IAVL×0.5×tAVL×fc ------------------------------------------- (2) fc: Hz units (fc is set to the PWM frequency of 50kHz.) For VDSS, IAVL, and tAVL, be sure to actually operate the STK672-2** Series and substitute values when operations are observed using an oscilloscope. Ex. If VDSS=110V, IAVL=1A, tAVL=0.2μs when using a STK672-220-E driver, the result is: PAVL=110×1×0.5×0.2×10-6×50×103=0.55W VDSS=110V is a value actually measured using an oscilloscope. The allowable loss range for the allowable avalanche energy value, PAVL, is shown in the graph in Figure 3. When examining the avalanche energy, be sure to actually drive a motor and observe the ID, VDSS, and tAVL waveforms during operation, and then check that the result of calculating Equation (2) falls within the allowable range for avalanche operations. [ID and VDSS Operating Waveforms in Non-avalanche Mode] Although the waveforms during avalanche mode are given in Figure 1, sometimes an avalanche does not result during actual operations. Factors causing avalanche are listed below. • Poor coupling of the motor’s phase coils (electromagnetic coupling of A phase and AB phase, B phase and BB phase). • Increase in the lead inductance of the harness caused by the circuit pattern of the P.C. board and motor. • Increases in VDSS, tAVL, and IAVL in Figure 1 due to an increase in the supply voltage from 24V to 36V. If the factors above are negligible, the waveforms shown in Figure 1 become waveforms without avalanche as shown in Figure 2. Under operations shown in Figure 2, avalanche does not occur and there is no need to consider the allowable loss range of PAVL shown in Figure 3. VDS IOH: Motor current peak value ID ITF02558 Figure 2 Output Current, ID, and Voltage, VDS, Waveforms 2 of the STK672-2** Series when Driving a 2-Phase Stepping Motor with Constant Current Chopping No.7465-9/10 STK672-220-E Average power loss in the avalanche state, PAVL- W Figure 3 Allowable Loss Range, PAVL-IOH During STK672-220-E Avalanche Operations PAVL - IOH 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 0 0.5 1.0 1.5 2.0 2.5 Motor phase current, IOH - A 3.0 3.5 ITF02619 Note: The operating conditions given above represent a loss when driving a 2-phase stepping motor with constant current chopping. Because it is possible to apply 3W or more at IOH=0A, be sure to avoid using the MOSFET body diode that is used to drive the motor as a zener diode. [Smoke Emission Precuations] If any of the output pins 2, 3, 4, and 5 is held open, the electrical stress onto the driver due to the inductive energy accumulated in the motor could cause short-circuit followed by permanent damage to the internal MOSFET. As a result, the STK672-220-E may give rise to emit smoke. SANYO Semiconductor Co.,Ltd. assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein. SANYO Semiconductor Co.,Ltd. strives to supply high-quality high-reliability products, however, any and all semiconductor products fail or malfunction with some probability. It is possible that these probabilistic failures or malfunction could give rise to accidents or events that could endanger human lives, trouble that could give rise to smoke or fire, or accidents that could cause damage to other property. When designing equipment, adopt safety measures so that these kinds of accidents or events cannot occur. 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Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. Upon using the technical information or products described herein, neither warranty nor license shall be granted with regard to intellectual property rights or any other rights of SANYO Semiconductor Co.,Ltd. or any third party. SANYO Semiconductor Co.,Ltd. shall not be liable for any claim or suits with regard to a third party's intellectual property rights which has resulted from the use of the technical information and products mentioned above. This catalog provides information as of July, 2008. Specifications and information herein are subject to change without notice. PS No.7465-10/10