AND SMA7029M BENEFITS AND FEATURES

Size: px

Start display at page:

Download "AND SMA7029M BENEFITS AND FEATURES"

Ralf Burke
5 years ago
Views:

1 OUT OFF DELY REFERENCE GROUND IN OUT SENSE CNTRL SPLY SENSE B OUT B OFF DELY B GROUND B REFERENCE B IN B OUT B SM729M V REF V REF BSOLUTE MXIMUM RTINGS at T = 25 C Load Supply Voltage, V BB V FET Output Voltage, V DS V Control Supply Voltage, V Peak Output Current, I OUTM (t w 1 µs) SL724M SL726M SM729M Continuous Output Current, I OUT SL724M SL726M SM729M Input Voltage Range, V IN V to 7. V Reference Voltage, V REF V Package Power Dissipation, P D. See Graph Junction Temperature, T J C Operating Temperature Range, T C to 85 C Storage Temperature Range, T stg C to 15 C UNIPOLR STEPPER MOTOR CONTROL/LOGIC CONTROL/LOGIC Dwg. PK-7 SL724M, SL726M, ND SM729M The SL724M, SL726M, and SM729M are designed for high-efficiency and high-performance operation of 2-phase, unipolar stepper motors. n automated, innovative packaging technology combined with power FETs and monolithic logic/control circuitry advances power multi-chip modules (PMCMs) toward the complete integration of motion control. Highly automated manufacturing techniques provide low-cost and exceptionally reliable PMCMs suitable for controlling and directly driving a broad range of 2-phase, unipolar stepper motors. The three stepper motor multi-chip modules differ primarily in output current ratings (1.5 or 3. ) and package style. ll three PMCMs are rated for an absolute maximum limit of 46 V and utilize advanced NMOS FETs for the high-current, high-voltage driver outputs. The avalanche-rated ( 1 V) FETs provide excellent ON resistance, improved body diodes, and very-fast switching. The multi-chip ratings and performance afford significant benefits and advantages for stepper drives when compared to the higher dissipation and slower switching speeds associated with bipolar transistors. Normally, heat sinks are not required for the SL724M or SM729M. The SL726M, in demanding, higher-current systems designs, necessitates suitable heat transfer methods for reliable operation. Complete applications information is given on the following pages. PWM current is regulated by appropriately choosing current-sensing resistors, a voltage reference, a voltage divider, and RC timing networks. The RC components limit the OFF interval and control current decay. Inputs are compatible with 5 V logic and microprocessors. BENEFITS ND FETURES Cost-Effective, Multi-Chip Solution Turn-Key Motion-Control Module Motor Operation to 3 and 46 V 3 rd Generation High-Voltage FETs 1 V, valanche-rated NMOS Low r DS(on) NMOS Outputs dvanced, Improved Body Diodes Single-Supply Motor/Module Operation lways order by complete part number: Half- or Full-Step Unipolar Drive High-Efficiency, High-Speed PWM Dual PWM Current Control (2-Phase) Programmable PWM Current Control Low Component Count PWM Drive Low Internal Power Dissipation Heat Sinking (Normally) Unnecessary Electrically Isolated Power Tab Logic IC- and µp-compatible Inputs Machine-Insertable Package Part Number Package Output Current SL724M 18-Lead Power-Tab SIP 1.5 SL726M 18-Lead Power-Tab SIP 3. SM729M 15-Lead SIP 1.5 Data Sheet 2821

2 SL724M and SL726M FUNCTIONL BLOCK DIGRM CONTROL SUPPLY IN /B IN /B OUT /B OUT /B REG. REFERENCE OFF-TIME DELY 2 4 GROUND CHNNEL PIN NUMBERS 9 SENSE CHNNEL B PIN NUMBERS Dwg. FK-5 Note that channels and B are electrically isolated. SM729M FUNCTIONL BLOCK DIGRM CONTROL SUPPLY IN /B OUT /B OUT /B REG. REFERENCE Note that except for the control supply, channels and B are electrically isolated. 11 OFF-TIME DELY 2 4 GROUND CHNNEL PIN NUMBERS CHNNEL B PIN NUMBERS 7 SENSE Dwg. FK Northeast Cutoff, Box 1536 Worcester, Massachusetts (58) Copyright 1994 llegro MicroSystems, Inc.

3 LLOWBLE PCKGE POWER DISSIPTION SL724M and SL726M LLOWBLE PCKGE POWER DISSIPTION in WTTS PREFIX 'SL' R θjm = 5. C/W PREFIX 'SM' R θjm = 6. C/W PREFIX 'SL' R θj = 28 C/W PREFIX 'SM' R θj = 31 C/W TEMPERTURE in C Dwg. GK-18 CONTROL/LOGIC CONTROL/LOGIC VREF VCC VCC VREF OUT OFF DELY REFERENCE GROUND IN IN CNTRL SPLY OUT SENSE SENSE B OUT B CNTRL SPLY B OFF DELY B REFERENCE B GROUND B IN B IN B OUT B Dwg. PK-6 ELECTRICL CHRCTERISTICS at T = 25 C Limits Characteristic Symbol Test Conditions Min Typ Max Units FET Leakage Current I DSS V DS = 1 V, = 44 V 4. m FET ON Voltage V DS(ON) (SL724M & SM729M) = 14 V, I OUT = 1 6 mv (SL726M) = 14 V, I OUT = 3 85 mv FET ON Resistance r DS(on) (SL724M & SM729M) = 14 V, I OUT = 1 6 mω (SL726M) = 14 V, I OUT = mω Body Diode V SD (SL724M & SM729M) I OUT = V Forward Voltage (SL726M) I OUT = V Control Supply Voltage Operating V Control Supply Current I CC = 44 V 1 15 m Input Current I IN(H) = 44 V, V IN = 2.4 V 4 µ I IN(L) V IN =.4 V -8 µ Input Voltage V IN(H) 2. V V IN(L).8 V NOTE: Negative current is defined as coming out of (sourcing) the specified device pin.

4 TYPICL STEPPER MOTOR PPLICTIONS (Half of Each Device Shown) SL724M and SL726M V BB IN B IN B OUT B OUT B 5 V REG. R 51 Ω 1 TO CHNNEL R 1 Ω kω R 5 V REF 14 t d 13 SENSE V 47 kω 47 pf R 3 C 1 C 3 22 pf R S 1 Ω WVE DRIVE (FULL STEP) for SL724M and SL726M Sequence Input H L L L H Input L L H L L Input B L H L L L Input B L L L H L Output ON B B Dwg. EK-8 TRUTH TBLES (Device Types as Designated) 2-PHSE (FULL STEP) OPERTION for SL724M and SL726M Sequence Input H L L H H Input L H H L L Input B H H L L H Input B L L H H L Outputs ON B B B B B HLF-STEP OPERTION (2-1-2 SEQUENCE) for SL724M, SL726M, and SM729M Sequence Input H H L L L L L H H Input or t d * L L L H H H L L L Input B L H H H L L L L L Input B or t db * L L L L L H H H L Output(s) ON B B B B B B *Logic signals to external open-collector inverter connected to t d and t db. 115 Northeast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

5 TYPICL STEPPER MOTOR PPLICTIONS (Half of Device Shown) SM729M V BB IN B 8 14 OUT B 1 15 OUT B 5 V REG. R 51 Ω 1 TO CHNNEL R 1 Ω kω R 5 V REF 13 t d 11 SENSE V R 3 OPEN-COLLECTOR INVERTER 47 kω C 1 47 pf C 3 22 pf R 1 S Ω Dwg. EK-8-1 TRUTH TBLES (SM729M Only) WVE DRIVE (FULL STEP) for SM729M Sequence Input H L L L H Input td* L L H L L Input B L H L L L Input tdb* L L L H L Output ON B B *Logic signals to external open-collector inverter connected to t d and t db. 2- PHSE (FULL STEP) OPERTION for SM729M Sequence Input H H L L H Input B L H H L L Outputs ON B B B B B

6 PPLICTIONS INFORMTION REGULTING THE PWM OUTPUT CURRENT The output current (and motor coil current) waveform is illustrated in Figure 1. Setting the PWM current trip point requires various external components: = Reference supply (typically 5 V) R 1, R 2 = Voltage-divider resistors in the reference supply circuit R S = Current sensing resistor(s) NOTE: The maximum allowable V REF input voltage is 2. V. The voltage-divider must be selected accordingly. Normal PWM (Full-Current/Running) Mode I OUT is set to meet the specified running current for the motor (Figure 2) and is determined by: I OUT V REF (1) R S or, if V REF is not known I OUT R 2 R 1 R 2 (2) R S PHSE I OUT PHSE Dwg. WK-1 FIGURE 1. PHSE COIL CURRENT WVEFORM V CC INPUT V BB B R 1 R 3 B R 2 R 5 C 1 t d V REF PEK CURRENT DETECTOR PWM OFF-TIME CONTROL CONTROL LOGIC CURRENT CONTROL & RECIRCULTING CURRENT CONTROL C 3 SENSE R S Dwg. EK-9 FIGURE 2. PWM CONTROL (RUN MODE) 115 Northeast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

7 For given values of R 1, R 2, and (V REF.82 V), Figure 3 illustrates output current as a function of current-sensing resistance (R S ). 3. SL726M MX. OUTPUT TRIP CURRENT in MPERES SL724M & SM729M MX. R1 = 51 Ω R2 = 1 Ω RX = Vb = 5 V CURRENT-SENSING RESISTNCE in OHMS Dwg. GK-14 FIGURE 3. CURRENT-SENSING RESISTNCE Reduced/Holding Current Mode dditional circuitry (Figure 4) enables reducing motor current. The external transistor changes the voltage-divider ratio, V REF, and reduces the output current. I HOLD is determined by resistors R 2 and R X in parallel: R 2 R X I HOLD R 1 R 2 R 1 R X R 2 R X (3) R S or R 2 I HOLD R 1 R 2 (4) R S where R 2 = the equivalent value of R 2 and R X in parallel. R 1 R X R 5 V REF HOLD R 2 C 3 SENSE R S Dwg. EK-1 FIGURE 4. HOLD CURRENT MODE

8 For given values of R 1, R 2, and (V REF.82 V), Figures 5 and 5B illustrate output holding current as a function of R X for two values of currentsensing resistance (R S ). 1. RS =.8 Ω OUTPUT TRIP CURRENT in MPERES RS = 1. Ω R1 = 51 Ω R2 = 1 Ω Vb = 5 V HOLDING-CURRENT RESISTNCE in OHMS 3. FIGURE 5. HOLD-CURRENT RESISTNCE (SL724M and SM729M) Dwg. GK-15 R1 = 51 Ω 2.5 R2 = 1 Ω OUTPUT TRIP CURRENT in MPERES Vb = 5 V RS =.33 Ω RS =.47 Ω HOLDING-CURRENT RESISTNCE in OHMS Dwg. GK-15-1 FIGURE 5B. HOLD-CURRENT RESISTNCE (SL726M) NOTE: Holding current determines holding torque, which is normally greater than running torque. Consult motor manufacturer for recommended safe holding current and motor winding temperature limits in standstill or detent mode. The MOSFET outputs create ringing noise with PWM, but the RC filter precludes malfunctions. The comparator operation is affected by R 5 and C 3 and, thus, current overshoot is influenced by component values. Empirical adjustment to fine-tune the current limit is likely. 115 Northeast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

9 DETERMINING THE MOTOR PWM FREQUENCY The modules function asynchronously, with PWM OFF time fixed by R 3 and C 1 at input t d. The OFF time can be calculated as: t OFF -R 3 C 1 log n (1-2 ) (5) Recommended circuit constants and t OFF are: = 5 V R 3 = 47 kω C 1 = 47 pf t OFF = 12 µs 5 ON TIME in µs RS = 1 Ω L/R = 1 to 3 ms VCC = 24 V VCC = 36 V CHOPPING FREQUENCY in khz MOTOR RESISTNCE in OHMS Dwg. GK-16 FIGURE 7. PWM FREQUENCY vs MOTOR RESISTNCE POWER DISSIPTION CLCULTIONS Excepting high-current applications utilizing the SL726M above approximately 2. at 65 C (with 2-phase operation), the need for heat sinks is rare. The basic constituents of conduction losses (internal power dissipation) include: (a) FET output power dissipation (I OUT 2 r DS(on) or I OUT V DS(ON) ), (b) FET body diode power dissipation (V SD I OUT ), and (c) control circuit power dissipation ( I CC ). Device conduction losses are calculated based on the operating mode (wave drive, half-step, or 2-phase). ssuming a 5% output duty cycle: Wave Drive =.5 (I OUT 2 r DS(on) ).5 (V SD I OUT ) ( 15 m) Half-Step =.75 (I OUT 2 r DS(on) ).75 (V SD I OUT ) ( 15 m) 2-Phase = (I OUT 2 r DS(on) ) (V SD I OUT ) ( 15 m)

10 PCKGE RTINGS/DERTING FCTORS Thermal ratings/deratings for the multi-chip module packages vary slightly. Normally, the SL724M and SM729M do not need heat sinking when operated within maximum specified output current ( 1. with 2-phase drive) unless the design ambient temperature also exceeds 6 C. Thermal calculations must also consider the temperature effects on the output FET ON resistance. The applicable thermal ratings for the PMCM packages are: SL724M and SL726M 18-Lead Power-Tab SIP R ΘJ = 28 C/W (no heat sink) or 4.5 W at 25 C and a derating factor of -36 mw/ C for operation above 25 C. R ΘJC = 5 C/W. SM729M 15-Lead SIP R ΘJ = 31 C/W (no heat sink) or 4. W at 25 C and a derating factor of -32 mw/ C for operation above 25 C. R ΘJC = 6 C/W. TEMPERTURE EFFECTS ON FET r DS(on) nalyzing safe, reliable operation includes a concern for the relationship of NMOS ON resistance to junction temperature. Device package power calculations must include the increase in ON resistance (producing higher output ON voltages) caused by higher operating junction temperatures. Figure 8 provides a normalized ON resistance curve, and all thermal calculations should consider increases from the given 25 C limits, which may be caused by internal heating during normal operation. 2.5 NORMLIZED FET ON RESISTNCE JUNCTION TEMPERTURE in C Dwg. GK-17 FIGURE 8. NORMLIZED ON RESISTNCE vs TEMPERTURE 115 Northeast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

11 SL724M and SL726M Dimensions in Inches (for reference only) ±.6 x ±.6 ø ± ± ± ±.28 Dwg. MK-2-18 in Dimensions in Millimeters (controlling dimensions) 31± ±.15 x ø ± ± ± ± ±.1 16 ± ±.2 13 ± ± ± ± ± ±.7 Dwg. MK-2-18 mm NOTES: 1. Exact body and lead configuration at vendor s option within limits shown. 2. Recommended mounting hardware torque: lbf ft (6 8 kgf cm or Nm). 3. The hatched area is exposed (electrically isolated) heat spreader. 4. Recommend use of metal-oxide-filled, alkyl-degenerated oil base, silicone grease (Dow Corning 34 or equivalent).

12 SM729M Dimensions in Inches (for reference only) 1.24 MX MX ± ± ± ±.28 Dwg. MK-5-15 in Dimensions in Millimeters (controlling dimensions) 31.5 MX. 31±.2 4. ± ± ± MX ± ± ± ±.7 Dwg. MK-5-15 mm NOTE: Exact body and lead configuration at vendor s option within limits shown. The products described here are manufactured in Japan by Sanken Electric Co., Ltd. for sale by llegro MicroSystems, Inc. Sanken Electric Co., Ltd. and llegro MicroSystems, Inc. reserve the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the design of their products. The information included herein is believed to be accurate and reliable. However, Sanken Electric Co., Ltd. and llegro MicroSystems, Inc. assume no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use. 115 Northeast Cutoff, Box 1536 Worcester, Massachusetts (58) 853-5

SLA7024M, SLA7026M, AND SMA7029M

SLA7024M, SLA7026M, AND SMA7029M OUT OFF DELY REFERENCE GROUND IN OUT SENSE CNTRL SPLY SENSE B OUT B OFF DELY B GROUND B REFERENCE B IN B OUT B SM729M 2 3 4 5 6 7 8 9 2 3 4 5 V REF V REF BSOLUTE MXIMUM RTINGS at T = 25 C Load Supply Voltage,