SMA7036M 2-Phase Excitation 2-Phase Stepper Motor Unipolar Driver IC ■Absolute Maximum Ratings Parameter Motor supply voltage Control supply voltage FET Drain-Source voltage TTL input voltage SYNC terminal voltage Reference voltage Sense voltage Output current Power dissipation Channel temperature Storage temperature Ambient operating temperature Symbol V CC VS VDSS VIN VSYNC VREF V RS IO PD1 PD2 Tch Tstg Ta Ratings 46 46 100 −0.3 to +7 −0.3 to +7 −0.3 to +7 −5 to +7 1.5 4.0 (Ta =25°C) 28 (Tc=25°C) 150 −40 to +150 −20 to +85 Units V V V V V V V A W W °C °C °C ■Electrical Characteristics Parameter Symbol IS Condition Control supply voltage VS FET Drain-Source VDSS voltage Condition VDS FET ON voltage Condition VSD FET diode forward voltage Condition IDSS FET drain leakage current Condition V IH Condition Active H VIL Condition V IH IN terminal Condition Active L VIL Condition II Input current Condition VSYNCH Condition Input voltage V SYNCL Condition SYNC terminal ISYNCH Condition Input current ISYNCL Condition V REF Input Condition voltage V REF Condition REF terminal IREF Input Condition current RREF Internal resistance Condition Ton Condition Tr Condition Switching time Tstg min AC characteristics DC characteristics Control supply current Chopping OFF time 12 SMA7036M Condition Tf Condition TOFF Condition 10 100 Ratings typ 10 VS =44V 24 max 15 44 Units mA V V VS =44V, IDSS=250 µA 0.6 ID=1A, V S=10V 1.1 ISD=1A 250 VDSS=100V, VS =44V V V µA 2 ID=1A 0.8 V V DSS=100V 2 V DSS=100V 0.8 V ID=1A ±1 V S=44V, VI=0 or 5V µA 4.0 Synchronous chopping mode 0.8 V Asynchronous chopping mode 0.1 VS =44V, VYS=5V −0.1 mA VS =44V, VYS=0V 0 2.0 Reference voltage input 4.0 5.5 V Output FET OFF ±1 No synchronous trigger 40 Resistance between GND and REF terminal at synchronous trigger 1.5 VS =24V, ID=1A 0.5 VS =24V, ID=1A 0.9 VS =24V, ID=1A 0.1 VS =24V, ID=1A 12 VS =24V µA Ω µs µs 2-Phase Stepper Motor Unipolar Driver IC (2-Phase Excitation) SMA7036M ■Internal Block Diagram 5 8 14 10 15 Vs IN B 6 IN A 1 1, 6, 10, 15pin Description of pins Reg. Oscillator MOSFET gate drive circuit Reg. Chopping blanking timer (5 µ s typ) Chopping OFF timer (12 µ s typ) Chopping blanking timer (5 µ s typ) + + − − 12 11 Rs B SYNC B 13 GND B 3 REF B REF A 4 GND A Synchronous chopping circuit SYNC A Rs A 2 MOSFET gate drive circuit Chopping OFF timer (12 µ s typ) Synchronous chopping circuit 7 1pin 6pin 10pin 15pin Oscillator Excitation input Active H Active L OUT A OUT A OUT A OUT A OUT B OUT B OUT B OUT B 9 ■Diagram of Standard External Circuit (Recommended Circuit Constants) Vcc (46V max) + Excitation signal time chart 8 1 6 10 2-phase excitation 15 VS 2 SyncA INA 5 INB 14 INA SMA7036M Vb (5V) 11 PchMOS SyncB r1 RsA 7 r2 Rs RefA RefB 3 13 RsB 9 GA 4 GB INB clock IN A IN B 0 H L : r1 : r2 RS (1 to 2W) : PchMOS : Inv : 1 H H 2 L H 3 L L 0 H L 1 H H 8kΩ 2kΩ (VR) 1Ω typ HN1J02FU (Toshiba) 7404 12 Rs Inv Disable (High Active) SMA7036M 13 2-Phase Stepper Motor Unipolar Driver IC (2-Phase Excitation) SMA7036M ■External Dimensions (Unit: mm) Epoxy resin package 4±0.2 +0.2 0.65 –0.1 1.16 +0.2 –0.1 3 ±0.6 +0.2 0.55 –0.1 4±0.7 P2.03±0.1×14=28.42 1.2±0.1 (5.9) (7.5) P2.03±0.1×14=28.42 31.3 +0.2 12 3 · · · · · · · 15 1 2 3 · · · · · · · 15 Forming No. No.1054 14 SMA7036M Forming No. No.1055 +0.2 (3) 0.62±0.1 1.16±0.15 1.6 ±0.6 (9.7) 6.7 ±0.5 1.45±0.15 0.55 –0.1 Lot No. Part No. (4.6) 2.5±0.2 30° 8.5max 10.2±0.2 31±0.2 2-Phase Stepper Motor Unipolar Driver IC (2-Phase Excitation) SMA7036M Application Notes ■Outline Connect TTL or similar to the SYNC terminals and switch the SMA7036M is a stepper motor driver IC developed to reduce the number of external parts required by the conventional SYNC terminal level high or low. When the motor is not running, set the TTL signal high (SYNC SMA7029M. This IC successfully eliminates the need for some terminal voltage: 4 V or more) to make chopping synchronous. external parts without sacrificing the features of SMA7029M. The basic function pins are compatible with those of SMA7029M. When the motor is running, set the TTL signal low (SYNC terminal voltage: 0.8 V or less) to make chopping asynchronous. If chop- ■Notes on Replacing SMA7029M ping is set to synchronous when the motor is running, the motor torque deteriorates before the coil current reaches the set value. SMA7036M is pin-compatible with SMA7029M. When using If no abnormal noise occurs when the motor is not running, the IC on an existing board, the following preparations are necessary: ground the SYNC terminals (TTL not necessary). (1) Remove the resistors and capacitors attached for setting the chopping OFF time. (r3, r4, C1, and C2 in the catalog) (2) Remove the resistors and capacitors attached for preventing noise in the detection voltage VRS from causing malfunctioning and short the sections from which the resistors were re- SYNC_A TTL, etc. SYNC_B moved using jumper wires. (r5, r6, C3, and C4 in the catalog) (3) Normally, keep pins 2 and 11 grounded because their functions have changed to synchronous and asynchronous SMA7036M switching (SYNC terminals). For details, see "Circuit for Preventing Abnormal Noise When the Motor Is Not Running (SynSYNC voltage : Low → Chopping asynchronous SYNC voltage : High → Chopping synchronous chronous circuit)." (Low: asynchronous, High: synchronous) ■Circuit for Preventing Abnormal Noise When the Motor Is Not Running (Synchronous Circuit) A motor may generate abnormal noise when it is not running. The built-in synchronous chopping circuit superimposes a trigger signal on the REF terminal for synchronization between the two This phenomenon is attributable to asynchronous chopping be- phases. The figure below shows the internal circuit of the REF tween phases A and B. To prevent the phenomenon, SMA7036M contains a synchronous chopping circuit. Do not leave the SYNC terminal. Since the ∆ VREF varies depending on the values of R1 and R2, determine these values for when the motor is not run- terminals open because they are for CMOS input. ning within the range where the two phases are synchronized. 5V SMA7036M R1 VREF R2 3 REF_A 14 REF_B To comparator (high impedance) 40 Ω (typ.) 40 Ω (typ.) Sync/async switching signal ONE SHOT (tw=2 µ S) FET A/A gate drive signal ONE SHOT (tw=2 µ S) FET B/B gate drive signal VREF waveform VREF 0 ■Synchronous circuit operating waveform VREF Phase A 0 VRS VREF Phase B 0 VRS Synchronous circuit OFF Synchronous circuit ON SMA7036M 15 2-Phase Stepper Motor Unipolar Driver IC (2-Phase Excitation) ■Determining the Output Current SMA7036M Fig. 1 Waveform of coil current (Phase A excitation ON) Fig. 1 shows the waveform of the output current (motor coil curIO rent). The method of determining the peak value of the output current (IO) based on this waveform is shown below. (Parameters for determining the output current I O) Phase A 0 Vb: Reference supply voltage r1,r2: Voltage-divider resistors for the reference supply voltage Phase A RS: Current sense resistor (1) Normal rotation mode IO is determined as follows when current flows at the maximum level during motor rotation. (See Fig.2.) r2 Vb ................................................................ (1) IO ≅ • r1+r2 RS Fig. 2 Normal mode Vb(5V) (2) Power down mode r1 The circuit in Fig.3 (r x and Tr) is added in order to decrease the 3,(13) coil current. I O is then determined as follows. 1 IOPD ≅ • r1(r 2+rX) 1+ r2 V b ......................................................... (2) RS 7,(9) r2 • rX RS Equation (2) can be modified to obtain equation to determine rx. rX= 1 1 Vb r1 Rs • IOPD −1 − 1 Fig. 3 Power down mode r2 Vb(5V) Fig. 4 and 5 show the graphs of equations (1) and (2) respectively. r1 3,(13) rx Power down signal r2 7,(9) Tr RS Fig. 4 Output current IO vs. Current sense resistor RS Fig. 5 Output current IOPD vs. Variable current sense resistor rx 2.0 3 r2 · Vb IO= r1+r2 RS r1=510Ω r2=100Ω rx=∞ Vb=5V 2 1 0 0 1 2 3 Current sense resistor RS (Ω) 16 SMA7036M 4 Output current IOPD (A) Output current IO (A) 4 RS =0.5Ω 1.5 1 · Vb r1(r2+rX) RS 1+ r2 · rX r1=510Ω r2=100Ω Vb=5V IOPD= RS =0.8Ω 1.0 RS =1Ω 0.5 00 200 400 600 800 1000 1200 Variable current sense resistor rX (Ω) 2-Phase Stepper Motor Unipolar Driver IC (2-Phase Excitation) ■Thermal Design (2) The power dissipation Pdiss is obtained using the following An outline of the method for calculating heat dissipation is shown below. (1) Obtain the value of P H that corresponds to the motor coil current IO from Fig. 6 "Heat dissipation per phase PH vs. Output current IO." formula. 2-phase excitation: Pdiss ≅ 2PH +0.015×V S (W) 3 PH +0.015×V S (W) 2 (3) Obtain the temperature rise that corresponds to the calcu1-2 phase excitation: Pdiss ≅ lated value of Pdiss from Fig. 7 "Temperature rise." Fig. 6 Heat dissipation per phase PH vs. Output current IO 1.2 Fig. 7 Temperature rise 150 1.0 ∆T 0.8 0.6 VCC =44 V 24V 0.4 j 100 V 36 Motor : 23LM-C004 Holding mode V 15 ∆Tj–a (°C) ∆TC–a Heat dissipation per phase PH (W) SMA7036M C ∆T Natural cooling Without heatsink 50 0.2 0 0 0.2 0.4 0.6 0.8 Output current IO (A) 1.0 0 0 1 2 3 Total Power (W) 4 Thermal characteristics Case temperature rise ∆TC–a (°C) 30 Without heatsink Natural cooling 25 20 TC ( 4 pin) 15 Motor : PH265-01B Motor current IO=0.8A Ta=25°C VCC=24V, VS=24V 2-phase excitation 10 5 0 200 500 1K Response frequency (pps) SMA7036M 17 2-Phase Stepper Motor Unipolar Driver IC (2-Phase Excitation) ■Supply Voltage VCC vs. Supply Current ICC SMA7036M ■Torque Characteristics 2.0 400 Motor : 23LM-C004 1-phase excitation Holding mode IO : Output current 300 200 IO=1A 100 0 Pull-out torque (kg-cm) Supply current ICC (mA) 500 1.5 0.5 0.5A 0.2A 0 10 20 30 40 Motor : 23LM-C202 Output current IO =0.8A Motor supply voltage VCC =24V 2-phase excitation 1.0 0 50 100 50 50 40 40 Motor : 23LM-C202 IO = 0.8A at VCC=24V RS=1Ω 20 10 0 1K 5K ■Chopper frequency vs. Output current f (kHz) f (kHz) ■Chopper frequency vs. Supply voltage 30 500 Response frequency (pps) Supply voltage VCC (V) 30 Motor : 23LM-C202 VCC=24V RS=1Ω 20 10 0 10 20 30 40 50 0 0 0.2 VCC (V) 0.4 0.6 0.8 1.0 IO (A) ■Handling Precautions The input terminals of this product use C-MOS circuits. Observe the following precautions. ● Carefully control the humidity of the room to prevent the buildup of static electricity. Since static electricity is particularly a problem during the winter, be sure to take sufficient precautions. ● Take care to make sure that static electricity is not applied to the IC during wiring and assembly. Take precautions such as shorting the terminals of the printed wiring board to ensure that they are at the same electrical potential. 18 SMA7036M