SI-7600/SI-7600D Star Connection/Delta Connection 3-Phase Stepper Motor Driver ICs ■Absolute Maximum Ratings Parameter Load supply voltage Logic supply voltage Input voltage Reference input voltage Sense voltage Package power dissipation Junction temperature Operating temperature Storage temperature Symbol V BB VCC VIN V REF Vsense PD Tj Top Tstg Ratings 50 7 −0.3 to VCC −0.3 to VCC 1.5 1 −20 to +85 +125 −55 to +125 Units V V V V V W °C °C °C Ratings 15 to 45 3 to 5.5 0.2 to Vcc−2 Units V V V ■Recommended Operating Voltage Ranges Parameter Load supply voltage Logic supply voltage Reference input voltage (Ta=25°C) Symbol V BB VCC V REF ■Electrical Characteristics Parameter Load supply voltage Logic supply voltage Output voltage Load supply current Logic supply current Logic input voltage Logic input current Maximum clock frequency PFD input voltage PFD input current Reference input voltage Reference input current Sense voltage RC source current Off time 98 SI-7600/SI-7600D Symbol VBB V CC VOL1 VOL2 VOH1 VOH2 IBB ICC VIH Ratings min 15 3.0 8 0 VBB−15 VBB−1 typ 3.75 VIL IIH IIL F V Slow VMix V Fast IPFD VREF IREF V S1 V S2 IRC Toff max 45 5.5 15 1 VBB−8 VBB 25 10 1.25 20 −20 200 100 1.7 0.7 Units V V V V V V mA mA V V µA µA kHz VCC 1.3 0.3 ±50 V CC−2 0 ±10 V REF×0.2 VREF×0.17 220 1.1×Rt ×Ct V V V µA V µA V V µA Sec. Conditions VCC=5.5V VCC=5.5V VIN=V CC×0.75 VIN=V CC×0.25 Edge=0V Edge=VCC VREF=0~Vcc−2V Mode=VCC, VREF =0~VCC−2V Mode=0V, AVREF =0~VCC−2V 3-Phase Stepper Motor Driver ICs (Star Connection/Delta Connection) SI-7600/SI-7600D ■Internal Block Diagram/Diagram of Standard External Circuit + C1 Vcc C3 C2 + C4 VBB Clock OHA CW/CCW OHB Control signal C7 Reset OHC Control Logic PriBuffer OLA U Ena OLB V Edge OLC W F/H R5 Mode Vcc R1 C5 REF Current Control 1/5 Buffer Sense MOS Array R2 Rs PFD Vcc RC GND R3 C6 R4 Ct Rt Reference constants Rs:0.1 to 1Ω (1 to 5W) Rt:15k to 75kΩ Ct:420p to 1100pF C1:10 µ F/10V C2:100 µ F/63V C3 to C6:0.01 to 1 µ F C7:1000pF ex. SLA5017 at 4A max SLA5059 at 4A max SLA5060 at 6A max Io SLA5061 at 10A max (Sanken) R1+R2≤10kΩ (VREF:0.2 to VCC2-2V) R3+R4≤10kΩ (VPFD:0 to VCC2) R5:10kΩ ■Terminal Connection The package shapes of SI-7600 and SI-7600D are different, however the terminal connection is the same. PFD RC S VBB Vcc OHA Reset CW/CCW EDGE OLA CK OLB F/H OLC Ena GND Mode REF Pin No. Name Pin No. Name Pin No. Name Pin1 PFD Pin8 Full/Half Pin15 OLA OHB Pin2 Sense Pin9 Enable Pin16 OHC OHA Pin3 Vcc Pin10 Mode Pin17 OHB Pin4 Reset Pin11 REF Pin18 OHA Pin5 CW/CCW Pin12 GND Pin19 V BB Pin6 Edge Pin13 OLC Pin20 RC Pin7 Clock Pin14 OLB ■External Dimensions (Unless specified otherwise, all values are typical) SI-7600 (Units: mm) SI-7600D 12.6 24.50 1 10 1 0.8 max 1.27 0.4 10 1.30 1.27 max 7.62 7.8 0.51 min 2.2 max 0.89 0.7 2.54 2.54 min 5.08 max 11 5.5 20 11 6.30 20 0.25 0.48 0° to 15° SI-7600/SI-7600D 99 3-Phase Stepper Motor Driver ICs (Star Connection/Delta Connection) SI-7600/SI-7600D Application Notes 1. Outline counter is reset. Output remains disabled as long as the The SI-7600/SI-7600D is a control IC used with a power MOS Reset terminal level is high. FET array to drive a 3-phase stepper motor. Select the outputstage MOS FET according to the rated current of the motor. 4. Determining the control current The full step is 2-phase excitation when this IC is in a star con- The control current Io can be calculated as follows: nection but 3-phase excitation when it is in a delta connection. When the Mode terminal level is low 2. Features When the Mode terminal level is high IO≅VREF/(5×RS) ● Suitable for both star connection drive and delta connection drive IO≅VREF/(5×RS)→ 3-phase excitation IO≅VREF/(5.88×RS)→ 2-phase excitation ● Maximum load supply voltage VBB =45V ● Control logic supply voltage Vcc=3 to 5.5V The reference voltage can be set within the range of 0.2V to Vcc −2V. ● Supports star connection (2/2-3phase excitation) and delta (When the voltage is less than 0.2V, the accuracy of the refer- connection (3/2-3phase excitation) ence voltage divider ratio deteriorates.) ● Step switching timing by clock signal input ● Forward/reverse, hold, and motor-free control ● Step switching at the positive edge or positive/negative edge 5. About the Current Control System (Setting the Constant Ct/Rt) The SI-7600 uses a current control system of the self-excitation of the clock signal ● Control current automatic switching function for 2-3phase ex- type with a fixed chopping OFF time. citation (effective for star connection) The chopping OFF time is determined by the constant Ct/Rt. (Current control: 86% for 2-phase excitation, 100% for 3-phase The constant Ct/Rt is calculated by the formula TOFF≅1.1×Ct×Rt…… (1) excitation) ● Self-excitation constant-current chopping by external C/R The recommended range of constant Ct/Rt is as follows: ● Slow Decay, Mixed Decay, or Fast Decay selectable Ct: 420 to 1100pF ● Two package lineup: SOP (surface mounting) and DIP (lead Rt: 15 to 75kΩ (Slow Decay or Mixed Decay →560pF/47kΩ, Fast Decay → insertion) SOP…SI-7600, DIP …SI-7600D 470pF/20kΩ) ● Maximum output current depends on the ratings of the MOS Usually, set T OFF to a value where the chopping frequency becomes about 30 to 40kHz. FET array used The mode can be set to Slow Decay, Fast Decay, or Mixed De- 3. Input Logic Truth Table Input terminal CW/CCW Full/Half Enable Mode Low level High level CW CCW Disable Always 100% Decay mode 0 to 0.3V Fast Decay Enable 0.7V to 1.3V Mixed Decay 2-phase excitation: 85% 1.7V to Vcc Slow Decay 3-phase excitation: 100% Positive Positive/negative In Mixed Decay mode, the Fast/Slow time ratio can be set using the voltage applied to the PFD terminal. The calculated values (Note 2) Reset PFD applied voltage and decay mode PFD applied voltage 2-3phase excitation 2-phase excitation (Note 1) Edge cay depending on the PFD terminal input potential. Enable (Note 3) Internal logic reset output disable are summarized below. In this mode, the point of switching from Fast Decay to Slow Decay is determined by the RC terminal voltage that determines Select CW/CCW, Full/Half, or Edge when the clock level is low. the chopping OFF time and by the PFD input voltage VPFD. Note 1: The control current is always 85% for the full step (2- Formula (1) is used to determine the chopping OFF time. phase excitation) when the Mode terminal level is high. The Fast Decay time is then determined by the RC discharge The value of 100% control current is calculated at the time from the RC voltage (about 1.5V) to the PFD input voltage V REF/(5×Rs) terminal because a 1/5 buffer is built into (VPFD) when chopping is turned from ON to OFF. the reference section. counter increments both at the rising and falling edges. The Fast Decay time is V PFD …… (2) tOFFf ≅−R T×CT ×ln ( ) 1.5 Therefore, the duty ratio of the input clock should be set The Slow Decay time (tOFFs) is calculated by subtracting the value at 50%. of (2) from that of (1). tOFFS≅TOFF−tOFFf ……(3) Note 2: When the Edge terminal level is set high, the internal Note 3: When the Reset terminal level is set high, the internal 100 SI-7600/SI-7600D 3-Phase Stepper Motor Driver ICs (Star Connection/Delta Connection) Relationship between RC terminal voltage and output current Ton SI-7600/SI-7600D ● Power loss of Nch MOS FETs The power loss of Nch MOS FETs is caused by the ON resis- Toff ITrip tance or by the chopping-OFF regenerative current flowing through the body diodes. IOUT (This loss is not related to the current control method, Slow, 1.5V VPFD VRC Mixed, or Fast Decay.) The losses are ON resistance loss N1: N1=IM2×RDS(ON) 0.5V Fast Decay Slow Decay Body diode loss N2: N2=IM×VSD With these parameters, the loss PN per MOS FET is calculated depending on the actual excitation method as follows: 6. Method of Calculating Power Loss of Output MOS FET a) 2-phase excitation (T=TON+T OFF) The SI-7600 uses a MOS-FET array for output. The power loss b) 2-3 phase excitation (T=TON+TOFF) of this MOS FET array can be calculated as summarized below. PN=(N1+N2×T OFF/T)×(1/4)+(0.5N1+N2×TOFF/T)×(1/12) ●Determining power loss and heatsink when SLA5017 is This is an approximate value that does not reflect parameter variations or other factors during use in the actual application. PN=(N1+N2×T OFF/T)× (1/3) used Therefore, heat from the MOS FET array should actually be If the SLA5017 is used in an output section, the power losses of measured. a Pch MOS FET and an Nch MOS FET should be multiplied by ● Parameters for calculating power loss three and added to determine the total loss P of SLA5017. To calculate the power loss of the MOS FET array, the following In other words, P=3×PP+3×PN parameters are needed: The allowable losses of SLA5017 are (1) Control current Io (max) (2) Excitation method (3) Chopping ON-OFF time at current control: TON, T OFF, tOFFf (TON: ON time, TOFF: OFF time, tOFFf: Fast Decay time at OFF) Without heatsink: 5W θj-a=25°C/W Infinite heatsink: 35W θj-c=3.57°C/W Select a heatsink by considering the calculated losses, allowable losses, and following ratings: (4) ON resistance of MOS FET: RDS (ON) (5) Forward voltage of MOS FET body diode: VSD (W) 15 For (4) and (5), use the maximum values of the MOS FET specifications. Al he at 5 does not flow the body diodes.) k Wit hou t he ats ink sin Power dissipation P m (In Slow Decay mode, the chopping-OFF regenerative current 2m through the body diodes in Fast Decay mode. 0× tance and by the chopping-OFF regenerative current flowing 10 10 The power loss of Pch MOS FETs is caused by the ON resis- 0× ● Power loss of Pch MOS FETs 10 (3) should be confirmed on the actual application. The losses are ON resistance loss P1: P1=I M2×RDS (ON) Body diode loss P2: P2=I M×V SD 0 0 25 50 75 100 125 Ambient temperature Ta (°C) 150 With these parameters, the loss Pp per MOS FET is calculated depending on the actual excitation method as follows: a) 2-phase excitation (T=T ON +TOFF) PP= (P1×TON/T+P2×tOFFf/T)× (1/3) b) 2-3 phase excitation (T=TON +TOFF) PP= (P1×T ON/T+P2×tOFFf/T)×(1/4)+(0.5×P1×T ON/T+P2×tOFFf/ T)×(1/12) When selecting a heatsink for SLA5017, be sure to check the product temperature when in use in an actual applicaiton. The calculated loss is an approximate value and therefore contains a degree of error. Select a heatsink so that the surface Al fin temperature of SLA5017 will not exceed 100°C under the worst conditions. SI-7600/SI-7600D 101 3-Phase Stepper Motor Driver ICs (Star Connection/Delta Connection) SI-7600/SI-7600D 7. I/O Timing Chart 2-phase excitation 2-3 phase excitation Positive edge Positive edge Positive/negative edge CCW CW CK Reset Full/Half EDGE CW/CCW Ena OHA OHB OHC OLA OLB OLC 2-3 phase excitation Positive edge Positive/negative edge CW CK Reset Full/Half ED CW/CCW Ena OHA OHB OHC OLA OLB OLC 102 SI-7600/SI-7600D Disable CCW