L6470 dSPIN fully integrated microstepping motor driver with motion engine and SPI Datasheet − production data Features ■ Operating voltage: 8 - 45 V ■ 7.0 A out peak current (3.0 A r.m.s.) ■ Low RDS(on) Power MOSFETs ■ Programmable speed profile and positioning ■ Programmable power MOS slew rate ■ Up to 1/128 microstepping ■ Sensorless stall detection ■ SPI interface ■ Low quiescent and standby currents ■ Programmable non-dissipative overcurrent protection on high and low-side ■ Two levels of overtemperature protection POWERSO36 Application ■ Bipolar stepper motors Description The L6470, realized in analog mixed signal technology, is an advanced fully integrated solution suitable for driving two-phase bipolar stepper motors with microstepping. It integrates a dual low RDS(on) DMOS full bridge with all of the Table 1. HTSSOP28 power switches equipped with an accurate onchip current sensing circuitry suitable for nondissipative current control and overcurrent protection. Thanks to a unique control system, a true 1/128 steps resolution is achieved. The digital control core can generate user defined motion profiles with acceleration, deceleration, speed or target position, easily programmed through a dedicated registers set. All commands and data registers, including those used to set analogue values (i.e. current control value, current protection trip point, deadtime, PWM frequency, etc.) are sent through a standard 5Mbit/s SPI. A very rich set of protections (thermal, low bus voltage, overcurrent, motor stall) allows the design of a fully protected application, as required by the most demanding motor control applications. Device summary Order codes Package Packaging L6470H HTSSOP28 Tube L6470HTR HTSSOP28 Tape and reel L6470PD POWERSO36 Tube L6470PDTR POWERSO36 Tape and reel June 2012 This is information on a product in full production. Doc ID16737 Rev 4 1/70 www.st.com 70 Contents L6470 Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.3 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.1 Pin list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 5 Typical applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.1 Device power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.2 Logic I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.3 Charge pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.4 Microstepping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6.4.1 6.5 Absolute position counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.6 Programmable speed profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.6.1 6.7 6.8 2/70 Automatic full-step mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Infinite acceleration/deceleration mode . . . . . . . . . . . . . . . . . . . . . . . . . 24 Motor control commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.7.1 Constant speed commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.7.2 Positioning commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 6.7.3 Motion commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 6.7.4 Stop commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.7.5 Step-clock mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.7.6 GoUntil and ReleaseSW commands . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Internal oscillator and oscillator driver . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.8.1 Internal oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.8.2 External clock source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Doc ID16737 Rev 4 L6470 Contents 6.9 Overcurrent detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.10 Undervoltage lockout (UVLO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.11 Thermal warning and thermal shutdown . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.12 Reset and standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.13 External switch (SW pin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.14 Programmable DMOS slew rate, deadtime and blanking time . . . . . . . . . 31 6.15 Integrated analog-to-digital converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6.16 Internal voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6.17 BUSY\SYNC pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 6.18 7 6.17.1 BUSY operation mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 6.17.2 SYNC operation mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 FLAG pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Phase current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 7.1 PWM sinewave generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 7.2 Sensorless stall detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.3 Low speed optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 7.4 BEMF compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.5 Motor supply voltage compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 7.6 Winding resistance thermal drift compensation . . . . . . . . . . . . . . . . . . . . 37 8 Serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 9 Programming manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 9.1 Registers and flags description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 9.1.1 ABS_POS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 9.1.2 EL_POS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 9.1.3 MARK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.1.4 SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.1.5 ACC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.1.6 DEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.1.7 MAX_SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 9.1.8 MIN_SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 9.1.9 FS_SPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 9.1.10 KVAL_HOLD, KVAL_RUN, KVAL_ACC and KVAL_DEC . . . . . . . . . . . . 44 Doc ID16737 Rev 4 3/70 Contents L6470 9.2 9.1.11 INT_SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 9.1.12 ST_SLP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.1.13 FN_SLP_ACC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.1.14 FN_SLP_DEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.1.15 K_THERM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.1.16 ADC_OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9.1.17 OCD_TH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9.1.18 STALL_TH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9.1.19 STEP_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 9.1.20 ALARM_EN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 9.1.21 CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 9.1.22 STATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Application commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 9.2.1 Command management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 9.2.2 Nop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 9.2.3 SetParam (PARAM, VALUE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 9.2.4 GetParam (PARAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 9.2.5 Run (DIR, SPD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 9.2.6 StepClock (DIR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 9.2.7 Move (DIR, N_STEP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 9.2.8 GoTo (ABS_POS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 9.2.9 GoTo_DIR (DIR, ABS_POS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 9.2.10 GoUntil (ACT, DIR, SPD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 9.2.11 ReleaseSW (ACT, DIR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 9.2.12 GoHome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 9.2.13 GoMark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 9.2.14 ResetPos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 9.2.15 ResetDevice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 9.2.16 SoftStop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 9.2.17 HardStop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 9.2.18 SoftHiZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 9.2.19 HardHiZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 9.2.20 GetStatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 10 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 11 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 4/70 Doc ID16737 Rev 4 L6470 List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Table 21. Table 22. Table 23. Table 24. Table 25. Table 26. Table 27. Table 28. Table 29. Table 30. Table 31. Table 32. Table 33. Table 34. Table 35. Table 36. Table 37. Table 38. Table 39. Table 40. Table 41. Table 42. Table 43. Table 44. Table 45. Table 46. Table 47. Table 48. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Typical application values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 CL values according to external oscillator frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Registers map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 EL_POS register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 MIN_SPEED register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Voltage amplitude regulation registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Winding resistance thermal drift compensation coefficient . . . . . . . . . . . . . . . . . . . . . . . . . 45 ADC_OUT value and motor supply voltage compensation feature . . . . . . . . . . . . . . . . . . 46 Overcurrent detection threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Stall detection threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 STEP_MODE register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Step mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 SYNC output frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 SYNC signal source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 ALARM_EN register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 CONFIG register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Oscillator management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 External switch hard stop interrupt mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Overcurrent event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Programmable power bridge output slew rate values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Motor supply voltage compensation enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 PWM frequency: integer division factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 PWM frequency: multiplication factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Available PWM frequencies [kHz]: 8-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . . 52 Available PWM frequencies [kHz]: 16-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . 52 Available PWM frequencies [kHz]: 24-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . 53 Available PWM frequencies [kHz]: 32-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . 53 STATUS register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 STATUS register DIR bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 STATUS register MOT_STATE bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Application commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Nop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 SetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 GetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Run command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Stepclock command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Move command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 GoTo command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 GoTo_DIR command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 GoUntil command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 ReleaseSW command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 GoHome command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Doc ID16737 Rev 4 5/70 List of tables Table 49. Table 50. Table 51. Table 52. Table 53. Table 54. Table 55. Table 56. Table 57. Table 58. Table 59. 6/70 L6470 GoMark command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 ResetPos command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 ResetDevice command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 SoftStop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 HardStop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 SoftHiZ command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 HardHiZ command structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 GetStatus command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 POWERSO36 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Doc ID16737 Rev 4 L6470 List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 HTSSOP28 pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 POWERSO36 pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Bipolar stepper motor control application using L6470 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Charge pump circuitry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Normal mode and microstepping (128 microsteps) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Automatic full-step switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Speed profile in infinite acceleration/deceleration mode . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Constant speed command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Positioning command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Motion command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 OSCIN and OSCOUT pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 External switch connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Internal 3 V linear regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Current distortion and compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 BEMF compensation curve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Motor supply voltage compensation circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 SPI timings diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Daisy chain configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Command with 3-byte argument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Command with 3-byte response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Command response aborted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 POWERSO36 drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Doc ID16737 Rev 4 7/70 Block diagram 1 L6470 Block diagram Figure 1. Block diagram VDD OSCIN 16MHz Oscillator OSCOUT ADCIN VREG CP VBOOT Charge pump Ext. Osc. driver & Clock gen. ADC STBY/RST VSA 3V Voltage Reg. FLAG V boot V boot HS A1 VSA HS A2 Registers OUT1A V DD HS A1 OUT2A LS A1 HS A2 LS A1 LS A2 LS A2 Control Logic PGND VSB HS B1 LS B1 CS V boot V boot VSB HS B2 SPI CK SDO LS B2 HS B1 HS B2 OUT1B SDI OUT2B BUSY/SYNC STCK Temperature sensing Current DACs & Comparators LS B1 LS B2 PGND V DD Current sensing SW DGND AGND AM02377v1 8/70 Doc ID16737 Rev 4 L6470 Electrical data 2 Electrical data 2.1 Absolute maximum ratings Table 2. Absolute maximum ratings Symbol Parameter Test condition Logic interface supply voltage VDD VS Motor supply voltage VGND, diff VSA = VSB = VS Differential voltage between AGND, PGND and DGND Value Unit 5.5 V 48 V ±0.3 V Vboot Bootstrap peak voltage 55 V VREG Internal voltage regulator output pin and logic supply voltage 3.6 V VADCIN Integrated ADC input voltage range (ADCIN pin) -0.3 to +3.6 V VOSC OSCIN and OSCOUT pin voltage range -0.3 to +3.6 V Vout_diff Differential voltage between VSA, OUT1A, OUT2A, PGND and VSB, OUT1B, OUT2B, PGND pins 48 V VLOGIC Logic inputs voltage range -0.3 to +5.5 V 3 A 7 A 150 °C -55 to 150 °C 5 W Iout (1) Iout_peak TOP Ts Ptot VSA = VSB = VS R.m.s. output current (1) Pulsed output current TPULSE < 1 ms Operating junction temperature Storage temperature range Total power dissipation (TA = 25 ºC) (2) 1. Maximum output current limit is related to metal connection and bonding characteristics. Actual limit must satisfy maximum thermal dissipation constraints. 2. HTSSOP28 mounted on EVAL6470H. Doc ID16737 Rev 4 9/70 Electrical data 2.2 L6470 Recommended operating conditions Table 3. Recommended operating conditions Symbol Parameter Test condition Value 3.3 V logic outputs VDD VS V 5 V logic outputs 5 VSA = VSB = VS Vout_diff Differential voltage between VSA, OUT1A, OUT2A, PGND and VSB, OUT1B, OUT2B, PGND pins VSA = VSB = VS VREG,in Logic supply voltage VREG voltage imposed by external source Tj 2.3 3.3 Logic interface supply voltage Motor supply voltage VADC Unit Integrated ADC input voltage (ADCIN pin) Operating junction temperature 8 3.2 45 V 45 V 3.3 V 0 VREG V - 25 125 °C Thermal data Table 4. Symbol Thermal data Parameter Package HTSSOP28 RthJA Thermal resistance junction-ambient Typ. (1) POWERSO36 (2) Unit 22 °C/W 12 1. HTSSOP28 mounted on EVAL6470H rev 1.0 board: four-layer FR4 PCB with a dissipating copper surface of about 40 cm2 on each layer and 15 via holes below the IC. 2. POWERSO36 mounted on EVAL6470PD rev 1.0 board: four-layer FR4 PCB with a dissipating copper surface of about 40 cm2 on each layer and 22 via holes below the IC. 10/70 Doc ID16737 Rev 4 L6470 3 Electrical characteristics Electrical characteristics VSA = VSB = 36 V; VDD = 3.3 V; internal 3 V regulator; TJ = 25 °C, unless otherwise specified. Table 5. Electrical characteristics Symbol Parameter Test condition Min. Typ. Max. Unit General VSthOn VS UVLO turn-on threshold 7.5 8.2 8.9 V VSthOff VS UVLO turn-off threshold 6.6 7.2 7.8 V VSthHyst VS UVLO threshold hysteresis 0.7 1 1.3 V Iq Quiescent motor supply current 0.5 0.65 mA Tj(WRN) Tj(SD) Internal oscillator selected; VREG = 3.3 V ext; CP floating Thermal warning temperature 130 °C Thermal shutdown temperature 160 °C 10 V 660 kHz 800 kHz Charge pump Vpump fpump,min fpump,max Iboot Voltage swing for charge pump oscillator Minimum charge pump oscillator frequency (1) Maximum charge pump oscillator frequency (1) Average boot current fsw,A = fsw,B = 15.6 kHz POW_SR = '10' 1.1 Tj = 25 °C, Iout = 3 A 0.37 Tj = 125 °C, (2) Iout = 3 A 0.51 Tj = 25 °C, Iout = 3 A 0.18 Tj = 125 °C, (2) Iout = 3 A 0.23 1.4 mA Output DMOS transistor RDS(on) RDS(on) IDSS tr High-side switch on-resistance Low-side switch on-resistance Leakage current OUT = VS OUT = GND Rise time (3) 3.1 mA -0.3 POW_SR = '00', Iout = +1 A 100 POW_SR = '00', Iout = -1 A 80 POW_SR = '11', Iout = ±1 A 100 POW_SR = '10', Ilout = ±1 A 200 POW_SR = '01', Iout = ±1 A 300 Doc ID16737 Rev 4 Ω ns 11/70 Electrical characteristics Table 5. Electrical characteristics (continued) Symbol tf SRout_r SRout_f L6470 Parameter Fall time Test condition (3) Output rising slew rate Output falling slew rate Min. Typ. Max. Unit POW_SR = '00'; Iout = +1 A 90 POW_SR = '00'; Iout = -1 A 110 POW_SR = '11', Iout = ±1 A 110 POW_SR = '10', Iout = ±1 A 260 POW_SR = '01', Iload= ±1 A 375 POW_SR = '00', Iout = +1 A 285 POW_SR = '00', Iout = -1 A 360 POW_SR = '11', Iout = ±1 A 285 POW_SR = '10', Iout = ±1 A 150 POW_SR = '01', Iout = ±1 A 95 POW_SR = '00', Iout = +1 A 320 POW_SR = '00', Iout = -1 A 260 POW_SR = '11', Iout = ±1 A 260 POW_SR = '10', Iout = ±1 A 110 POW_SR = '01', Iout = ±1 A 75 POW_SR = '00' 250 POW_SR = '11', fOSC = 16 MHz 375 POW_SR = '10', fOSC = 16 MHz 625 POW_SR = '01', fOSC = 16 MHz 875 POW_SR = '00' 250 POW_SR = '11', fOSC = 16 MHz 375 POW_SR = '10', fOSC = 16 MHz 625 POW_SR = '01', fOSC = 16 MHz 875 ns V/µs V/µs Deadtime and blanking tDT tblank Deadtime (1) Blanking time (1) ns ns Source-drain diodes VSD,HS High-side diode forward ON voltage Iout = 1 A 1 1.1 V VSD,LS Low-side diode forward ON voltage Iout = 1 A 1 1.1 V trrHS High-side diode reverse recovery time Iout = 1 A 30 ns trrLS Low-side diode reverse recovery time Iout = 1 A 100 ns 12/70 Doc ID16737 Rev 4 L6470 Table 5. Electrical characteristics Electrical characteristics (continued) Symbol Parameter Test condition Min. Typ. Max. Unit Logic inputs and outputs VIL Low logic level input voltage VIH High logic level input voltage IIH IIL VOL 0.8 2 High logic level input current (4) VIN = 5 V Low logic level input current (5) VIN = 0 V Low logic level output voltage (6) -1 0.3 V VDD = 3.3 V, IOH = 4 mA 2.4 VDD = 5 V, IOH = 4 mA 4.7 335 CS pull-up and STBY pull-down resistors CS = GND; STBY/RST = 5 V Ilogic Internal logic supply current 3.3 V VREG externally supplied, internal oscillator Standby mode internal logic supply current 3.3 V VREG externally supplied µA µA VDD = 5 V, IOL = 4 mA RPU RPD fSTCK 1 0.3 High logic level output voltage Ilogic,STBY V VDD = 3.3 V, IOL = 4 mA VOH V V 430 565 kΩ 3.7 4.3 mA 2 2.5 µA 2 MHz Step-clock input frequency Internal oscillator and external oscillator driver Tj = 25 °C, VREG = 3.3 V fosc,i Internal oscillator frequency fosc,e Programmable external oscillator frequency -3% 16 8 +3% MHz 32 MHz VOSCOUTH OSCOUT clock source high level voltage Internal oscillator 3.3 V VREG externally supplied; IOSCOUT = 4 mA VOSCOUTL OSCOUT clock source low level voltage Internal oscillator 3.3 V VREG externally supplied; IOSCOUT = 4 mA 0.3 V trOSCOUT tfOSCOUT OSCOUT clock source rise and fall time Internal oscillator 20 ns 2.4 V textosc Internal to external oscillator switching delay 3 ms tintosc External to internal oscillator switching delay 1.5 µs SPI fCK,MAX Maximum SPI clock frequency (7) 5 MHz trCK tfCK SPI clock rise and fall time (7) thCK tlCK SPI clock high and low time (7) 75 ns Chip select setup time (7) 350 ns tsetCS CL = 30 pF Doc ID16737 Rev 4 25 ns 13/70 Electrical characteristics Table 5. L6470 Electrical characteristics (continued) Symbol Parameter tholCS Chip select hold time (7) tdisCS Deselect time (7) tsetSDI tholSDI Data input setup time Data input hold time Test condition (7) (7) Min. Typ. Max. Unit 10 ns 800 ns 25 ns 20 ns tenSDO Data output enable time (7) 38 ns tdisSDO Data output disable time (7) 47 ns 57 ns tvSDO tholSDO Data output valid time (7) Data output hold time (7) 37 ns Switch input (SW) RPUSW SW input pull-up resistance SW = GND 60 85 110 fosc = 16 MHz 2.8 62.5 fosc = 32 MHz 5.6 125 kΩ PWM modulators fPWM Programmable PWM frequency (1) NPWM PWM resolution kHz 8 bit Stall detection ISTALL,MAX Maximum programmable stall threshold STALL_TH = '1111111' 4 A ISTALL,MIN Minimum programmable stall threshold STALL_TH = '0000000' 31.2 5 mA ISTALL,RES Programmable stall threshold resolution 31.2 5 mA Overcurrent protection IOCD,MAX Maximum programmable overcurrent detection threshold OCD_TH = '1111' 6 A IOCD,MIN Minimum programmable overcurrent detection threshold OCD_TH = '0000' 0.37 5 A IOCD,RES Programmable overcurrent detection threshold resolution 0.37 5 A tOCD,Flag OCD to flag signal delay time dIout/dt = 350 A/µs 650 tOCD,SD OCD to shutdown delay time dIout/dt = 350 A/µs POW_SR = '10' 600 VS = 8 V 26 34 VS = 36 V 30 36 1000 ns ns Standby IqSTBY tSTBY,min tlogicwu 14/70 Quiescent motor supply current in standby conditions µA Minimum standby time 10 Logic power-on and wake-up time 38 Doc ID16737 Rev 4 µs 45 µs L6470 Table 5. Electrical characteristics Electrical characteristics (continued) Symbol tcpwu Parameter Test condition Charge pump power-on and wake-up time Min. Typ. Max. Unit Power bridges disabled, Cp = 10 nF, Cboot = 220 nF µs 650 Internal voltage regulator VREG Voltage regulator output voltage IREG Voltage regulator output current 2.9 VREG, drop Voltage regulator output voltage drop IREG,STBY Voltage regulator standby output current IREG = 40 mA 3 3.2 V 40 mA 50 mV 10 mA Integrated analog-to-digital converter NADC VADC,ref fS Analog-to-digital converter resolution Analog-to-digital converter reference voltage 5 bit VRE V G Analog-to-digital converter sampling frequency fPWM kHz 1. Accuracy depends on oscillator frequency accuracy. 2. Tested at 25 °C in a restricted range and guaranteed by characterization. 3. Rise and fall time depends on motor supply voltage value. Refer to SRout values in order to evaluate the actual rise and fall time. 4. Not valid for STBY/RST pin which has internal pull-down resistor. 5. Not valid for SW and CS pins which have internal pull-up resistors. 6. FLAG, BUSY and SYNC open drain outputs included. 7. See Figure 18 – SPI timings diagram for details. Doc ID16737 Rev 4 15/70 Pin connection 4 L6470 Pin connection Figure 2. HTSSOP28 pin connection (top view) /54! /54! 63! 0'.$ 34"9<234 63! 37 34#+ !$#). &,!' 62%' #3 /3#). "539<39.# /3#/54 $'.$ !'.$ 3$) #0 #+ 6"//4 3$/ 63" 6$$ 0'.$ /54" %0!$ 63" /54" !-V Figure 3. POWERSO36 pin connection (top view) 1(/% 065" 065" 74" 74" 45#:345 %*3 "%$*/ 73&( 04$*/ 04$065 "(/% $1 7#005 74# 74# 065# 065# 16/70 &1"% Doc ID16737 Rev 4 065" 065" 74" 74" 45$, '-"( $4 #64:=4:/$ %(/% 4%* $, 4%0 7%% 74# 74# 065# 065# 1(/% L6470 Pin connection 4.1 Pin list Table 6. Pin description No. Name Type Function HTSSOP POWERSO 17 24 VDD Power Logic outputs supply voltage (pull-up reference) 6 9 VREG Power Internal 3 V voltage regulator output and 3.3 V external logic supply 7 10 OSCIN Analog input Oscillator pin 1. To connect an external oscillator or clock source. If this pin is unused, it should be left floating. Analog output Oscillator pin 2. To connect an external oscillator. When the internal oscillator is used this pin can supply 2/4/8/16 MHz. If this pin is unused, it should be left floating. Output Charge pump oscillator output 8 11 OSCOUT 10 13 CP 11 14 VBOOT Supply voltage Bootstrap voltage needed for driving the high-side power DMOS of both bridges (A and B) 5 8 ADCIN Analog input Internal analog-to-digital converter input 2, 26 4, 5, 33, 34 VSA Power supply Full bridge A power supply pin. It must be connected to VSB. 12, 16 15, 16, 22, 23 VSB Power supply Full bridge B power supply pin. It must be connected to VSA. 27, 13 1, 19 PGND Ground Power ground pin 1 2, 3 OUT1A Power output Full bridge A output 1 28 35, 36 OUT2A Power output Full bridge A output 2 14 17, 18 OUT1B Power output Full bridge B output 1 15 20, 21 OUT2B Power output Full bridge B output 2 9 12 AGND Ground Analog ground. 4 7 SW Logical input External switch input pin. If not used the pin should be connected to VDD. 21 28 DGND Ground Digital ground By default, this BUSY pin is forced low when the device is performing a command. Otherwise the pin BUSY\SYNC Open drain output can be configured to generate a synchronization signal. 22 29 18 25 SDO Logic output Data output pin for serial interface 20 27 SDI Logic input Data input pin for serial interface 19 26 CK Logic input Serial interface clock 23 30 CS Logic input Chip select input pin for serial interface Doc ID16737 Rev 4 17/70 Pin connection Table 6. L6470 Pin description (continued) No. Name HTSSOP Type Function POWERSO Status flag pin. An internal open drain transistor can pull the pin to GND when a programmed alarm Open drain output condition occurs (step loss, OCD, thermal prewarning or shutdown, UVLO, wrong command, nonperformable command) 24 31 FLAG 3 6 STBY\RST Logic input Standby and reset pin. LOW logic level resets the logic and puts the device into Standby mode. If not used, it should be connected to VDD. 25 32 STCK Logic input Step-clock input EPAD EPAD 18/70 Exposed pad Ground Internally connected to PGND, AGND and DGND pins Doc ID16737 Rev 4 L6470 5 Typical applications Typical applications Table 7. Typical application values Name Value CVS 220 nF CVSPOL 100 µF CREG 100 nF CREGPOL 47 µF CDD 100 nF CDDPOL 10 µF D1 Charge pump diodes CBOOT 220 nF CFLY 10 nF RPU 39 kΩ RSW 100 Ω CSW 10 nF RA 2.7 kΩ (VS = 36 V) RB 62 kΩ (VS = 36 V) Doc ID16737 Rev 4 19/70 Typical applications Figure 4. 20/70 L6470 Bipolar stepper motor control application using L6470 Doc ID16737 Rev 4 L6470 Functional description 6 Functional description 6.1 Device power-up At power-up end, the device state is the following: ● Registers are set to default ● Internal logic is driven by internal oscillator and a 2 MHz clock is provided by the OSCOUT pin ● Bridges are disabled (High Z) ● UVLO bit in the STATUS register is forced low (fail condition) ● FLAG output is forced low. During power-up, the device is under reset (all logic IOs disabled and power bridges in high impedance state) until the following conditions are satisfied: ● VS is greater than VSthOn ● VREG is greater than VREGth = 2.8 V typical ● Internal oscillator is operative. Any motion command makes the device exit from High Z state (HardStop and SoftStop included). 6.2 Logic I/O Pins CS, CK, SDI, STCK, SW and STBY\RST are TTL/CMOS 3.3 V - 5 V compatible logic inputs. Pin SDO is a TTL/CMOS compatible logic output. VDD pin voltage sets the logic output pin voltage range; when it is connected to VREG or 3.3 V external supply voltage, the output is 3.3 V compatible. When VDD is connected to a 5 V supply voltage, SDO is 5 V compatible. VDD is not internally connected to VREG, an external connection is always needed. A 10 µF capacitor should be connected to the VDD pin in order to obtain a proper operation. Pins FLAG and BUSY\SYNC are open drain outputs. 6.3 Charge pump To ensure the correct driving of the high-side integrated MOSFETs, a voltage higher than the motor power supply voltage needs to be applied to the VBOOT pin. The high-side gate driver supply voltage, Vboot, is obtained through an oscillator and a few external components realizing a charge pump (see Figure 5). Doc ID16737 Rev 4 21/70 Functional description Figure 5. L6470 Charge pump circuitry 636#06$ #"//4 63 $ #&,9 636#06$6$ 6"//4 $ #0 6#0 TOHIGHSIDE GATEDRIVERS 6$$ F05-0 !-V 6.4 Microstepping The driver is able to divide the single step into up to 128 microsteps. Stepping mode can be programmed by the STEP_SEL parameter in the STEP_MODE register (see Table 18). Step mode can only be changed when bridges are disabled. Every time the step mode is changed the electrical position (i.e. the point of microstepping sinewave that is generated) is reset to the first microstep and the absolute position counter value (see Section 6.5) becomes meaningless. Figure 6. 2ESET POSITION Normal mode and microstepping (128 microsteps) .ORMALDRIVING 2ESET POSITION 0(!3%!CURRENT 0(!3%"CURRENT -ICROSTEPPING 0(!3%!CURRENT 0(!3%"CURRENT MICROSTEPS STEP STEP STEP STEP STEP STEP STEP STEP STEP STEP ª STEPS ª STEPS ª STEPS ª STEPS !-V 22/70 Doc ID16737 Rev 4 L6470 6.4.1 Functional description Automatic full-step mode When motor speed is greater than a programmable full-step speed threshold, the L6470 switches automatically to Full-step mode (see Figure 7); the driving mode returns to microstepping when motor speed decreases below the full-step speed threshold. The fullstep speed threshold is set through the FS_SPD register (see Section 9.1.9). Figure 7. Automatic full-step switching Ipeak sin(π/4) x Ipeak Phase A Phase B µStepping 6.5 µStepping Full-Step (2N+1) x π/4 (2N+1) x π/4 Absolute position counter An internal 22-bit register (ABS_POS) records the motor motion according to the selected step mode; the stored value unit is equal to the selected step mode (full, half, quarter, etc.). The position range is from -221to +221-1 (µ)steps (see Section 9.1.1). 6.6 Programmable speed profiles The user can easily program a customized speed profile defining independently acceleration, deceleration, maximum and minimum speed values by the ACC, DEC, MAX_SPEED and MIN_SPEED registers respectively (see Section 9.1.5, 9.1.6, 9.1.7 and 9.1.8). When a command is sent to the device, the integrated logic generates the microstep frequency profile that performs a motor motion compliant to speed profile boundaries. All acceleration parameters are expressed in step/tick2 and all speed parameters are expressed in step/tick; the unit of measurement does not depend on the selected step mode. Acceleration and deceleration parameters range from 2-40 to (212-2)• 2-40 step/tick2 (equivalent to 14.55 to 59590 step/s2). The minimum speed parameter ranges from 0 to (212-1)• 2-24 step/tick (equivalent to 0 to 976.3 step/s). The maximum speed parameter ranges from 2-18 to (210-1)• 2-18 step/tick (equivalent to 15.25 to 15610 step/s). Doc ID16737 Rev 4 23/70 Functional description 6.6.1 L6470 Infinite acceleration/deceleration mode When the ACC register value is set to max. (0xFFF), the system works in “infinite acceleration mode”: acceleration and deceleration phases are totally skipped, as shown in Figure 8. It is not possible to skip the acceleration or deceleration phase independently. Figure 8. Speed profile in infinite acceleration/deceleration mode 30%%$ 0ROGRAMMED MAXIMUM SPEED 0ROGRAMMEDNUMBEROFMICROSTEPS TIME TIME #ONSTANTSPEEDMODE )NDEXINGMODE 6.7 !-6 Motor control commands The L6470 can accept different types of commands: ● constant speed commands (Run, GoUntil, ReleaseSW) ● absolute positioning commands (GoTo, GoTo_DIR, GoHome, GoMark) ● motion commands (Move) ● stop commands (SoftStop, HardStop, SoftHiz, HardHiz). For detailed command descriptions refer to Section 9.2 on page 55. 6.7.1 Constant speed commands A constant speed command produces a motion in order to reach and maintain a userdefined target speed starting from the programmed minimum speed (set in the MIN_SPEED register) and with the programmed acceleration/deceleration value (set in the ACC and DEC registers). A new constant speed command can be requested anytime. 24/70 Doc ID16737 Rev 4 L6470 Functional description Figure 9. Constant speed command examples 3PEED STEPFREQUENCY 30$ 2UN30$"7 30$ 30$ 2UN30$&7 2UN30$&7 -INIMUM SPEED -INIMUM SPEED TIME 2UN30$&7 30$ !-V 6.7.2 Positioning commands An absolute positioning command produces a motion in order to reach a user-defined position that is sent to the device together with the command. The position can be reached performing the minimum path (minimum physical distance) or forcing a direction (see Figure 10). The performed motor motion is compliant to programmed speed profile boundaries (acceleration, deceleration, minimum and maximum speed). Note that with some speed profiles or positioning commands, the deceleration phase can start before the maximum speed is reached. Figure 10. Positioning command examples &ORWARD DIRECTION 0RESENT POSITION 0RESENT POSITION 4ARGET POSITION 'O4O4ARGETPOS 6.7.3 4ARGET POSITION 'O4O?$)24ARGETPOS&7 !-V Motion commands Motion commands produce a motion in order to perform a user-defined number of microsteps in a user-defined direction that are sent to the device together with the command (see Figure 11). Doc ID16737 Rev 4 25/70 Functional description L6470 The performed motor motion is compliant to programmed speed profile boundaries (acceleration, deceleration, minimum and maximum speed). Note that with some speed profiles or motion commands, the deceleration phase can start before the maximum speed is reached. Figure 11. Motion command examples 30%%$ 30%%$ PROGRAMMEDNUMBEROFMICROSTEPS PROGRAMMEDNUMBEROFMICROSTEPS PROGRAMMED MAXIMUM SPEED PROGRAMMED MAXIMUM SPEED PROGRAMMED !##%,%2!4)/. PROGRAMMED MINIMUM SPEED PROGRAMMED !##%,%2!4)/. PROGRAMMED $%#%,%2!4)/. PROGRAMMED MINIMUM SPEED .OTEWITHSOME !CCELERATION$ECELARATIONPROFILES THEPROGRAMMEDMAXIMUMSPEED ISNEVERREACHED PROGRAMMED $%#%,%2!4)/. TIME TIME !-V 6.7.4 Stop commands A stop command forces the motor to stop. Stop commands can be sent anytime. The SoftStop command causes the motor to decelerate with programmed deceleration value until the MIN_SPEED value is reached and then stops the motor keeping the rotor position (a holding torque is applied). The HardStop command stops the motor instantly, ignoring deceleration constraints and keeping the rotor position (a holding torque is applied). The SoftHiZ command causes the motor to decelerate with programmed deceleration value until the MIN_SPEED value is reached and then forces the bridges in high impedance state (no holding torque is present). The HardHiZ command instantly forces the bridges into high impedance state (no holding torque is present). 6.7.5 Step-clock mode In Step-clock mode the motor motion is defined by the step-clock signal applied to the STCK pin. At each step-clock rising edge, the motor is moved one microstep in the programmed direction and the absolute position is consequently updated. When the system is in Step-clock mode, the SCK_MOD flag in the STATUS register is raised, the SPEED register is set to zero and motor status is considered stopped whatever the STCK signal frequency (MOT_STATUS parameter in STATUS register equal to “00”). 6.7.6 GoUntil and ReleaseSW commands In most applications the power-up position of the stepper motor is undefined, so an initialization algorithm driving the motor to a known position is necessary. The GoUntil and ReleaseSW commands can be used in combination with external switch input (see Section 6.13) to easily initialize the motor position. 26/70 Doc ID16737 Rev 4 L6470 Functional description The GoUntil command makes the motor run at the constant target speed until the SW input is forced low (falling edge). When this event occurs, one of the following actions can be performed: ● The ABS_POS register is set to zero (home position) and the motor decelerates to zero speed (as a SoftStop command) ● The ABS_POS register value is stored in the MARK register and the motor decelerates to zero speed (as a SoftStop command). If the SW_MODE bit of the CONFIG register is set to ‘0’, the motor does not decelerate but it immediately stops (as a HardStop command). The ReleaseSW command makes the motor run at the programmed minimum speed until the SW input is forced high (rising edge). When this event occurs, one of the following actions can be performed: ● The ABS_POS register is set to zero (home position) and the motor immediately stops (as a HardStop command) ● The ABS_POS register value is stored in the MARK register and the motor immediately stops (as a HardStop command). If the programmed minimum speed is less than 5 step/s, the motor is driven at 5 step/s. 6.8 Internal oscillator and oscillator driver The control logic clock can be supplied by the internal 16-MHz oscillator, an external oscillator (crystal or ceramic resonator) or a direct clock signal. These working modes can be selected by EXT_CLK and OSC_SEL parameters in the CONFIG register (see Table 23). At power-up the device starts using the internal oscillator and provides a 2-MHz clock signal on the OSCOUT pin. Attention: In any case, before changing clock source configuration, a hardware reset is mandatory. Switching to different clock configurations during operation may cause unexpected behavior. 6.8.1 Internal oscillator In this mode the internal oscillator is activated and OSCIN is unused. If the OSCOUT clock source is enabled, the OSCOUT pin provides a 2, 4, 8 or 16-MHz clock signal (according to OSC_SEL value); it is otherwise unused (see Figure 12). 6.8.2 External clock source Two types of external clock source can be selected: crystal/ceramic resonator or direct clock source. Four programmable clock frequencies are available for each external clock source: 8, 16, 24 and 32 MHz. When an external crystal/resonator is selected, the OSCIN and OSCOUT pins are used to drive the crystal/resonator (see Figure 12). The crystal/resonator and load capacitors (CL) Doc ID16737 Rev 4 27/70 Functional description L6470 must be placed as close as possible to the pins. Refer to Table 8 for the choice of load capacitor values according to the external oscillator frequency. Table 8. CL values according to external oscillator frequency Crystal/resonator freq. (1) CL (2) 8 MHz 25 pF (ESRmax = 80 Ω) 16 MHz 18 pF (ESRmax = 50 Ω) 24 MHz 15 pF (ESRmax = 40 Ω) 32 MHz 10 pF (ESRmax = 40 Ω) 1. First harmonic resonance frequency. 2. Lower ESR value allows the driving of greater load capacitors. If a direct clock source is used, it must be connected to the OSCIN pin and the OSCOUT pin supplies the inverted OSCIN signal (see Figure 12). Figure 12. OSCIN and OSCOUT pin configuration %84?#,+ %84?#,+ -(Z #, #, -(Z /3#?3%,XX /3#). /3#/54 %XTERNALOSCILLATOR CONFIGURATION /3#). /3#/54 %XTERNALCLOCKSOURCE CONFIGURATION -(Z /3#?3%,XX 5.53%$ 5.53%$ 5.53%$ /3#). /3#/54 /3#). )NTERNALOSCILLATOR CONFIGURATION WITHOUTCLOCKSOURCE /3#/54 )NTERNALOSCILLATOR CONFIGURATION WITHCLOCKGENERATION !-V Note: When OSCIN is UNUSED, it should be left floating. When OSCOUT is UNUSED, it should be left floating. 6.9 Overcurrent detection When the current in any of the Power MOSFETs exceeds a programmed overcurrent threshold, the STATUS register OCD flag is forced low until the overcurrent event has 28/70 Doc ID16737 Rev 4 L6470 Functional description expired and a GetStatus command is sent to the IC (see Section 9.1.22 and 9.1.17). The overcurrent event expires when all the Power MOSFET currents fall below the programmed overcurrent threshold. The overcurrent threshold can be programmed through the OCD_TH register in one of 16 available values ranging from 375 mA to 6 A with steps of 375 mA (see Table 9, Section 9.1.17). It is possible to set whether an overcurrent event causes or not the MOSFET turn-off (bridges in high impedance status) acting on the OC_SD bit in the CONFIG register (see Section 9.1.21). The OCD flag in the STATUS register is raised anyway (see Table 34, Section 9.1.22). When the IC outputs are turned off by an OCD event, they cannot be turned on until the OCD flag is released by a GetStatus command. Attention: The overcurrent shutdown is a critical protection feature. It is not recommended to disable it. 6.10 Undervoltage lockout (UVLO) The L6470 provides a motor supply UVLO protection. When the motor supply voltage falls below the VSthOff threshold voltage, the STATUS register UVLO flag is forced low. When a GetStatus command is sent to the IC, and the undervoltage condition has expired, the UVLO flag is released (see Section 9.1.22 and 9.2.20). The undervoltage condition expires when the motor supply voltage goes over the VSthOn threshold voltage. When the device is in undervoltage condition, no motion command can be performed. The UVLO flag is forced low by logic reset (power-up included) even if no UVLO condition is present. 6.11 Thermal warning and thermal shutdown An internal sensor allows the L6470 to detect when the device internal temperature exceeds a thermal warning or an overtemperature threshold. When the thermal warning threshold (Tj(WRN)) is reached, the TH_WRN bit in the STATUS register is forced low (see Section 9.1.22) until the temperature decreases below Tj(WRN) and a GetStatus command is sent to the IC (see Section 9.1.22 and 9.2.20). When the thermal shutdown threshold (Tj(OFF)) is reached, the device goes into thermal shutdown condition: the TH_SD bit in the STATUS register is forced low, the power bridges are disabled bridges in high impedance state and the HiZ bit in the STATUS register is raised (see Section 9.1.22). The thermal shutdown condition only expires when the temperature goes below the thermal warning threshold (Tj(WRN)). On exiting thermal shutdown condition, the bridges are still disabled (HiZ flag high); any motion command makes the device exit from High Z state (HardStop and SoftStop included). Doc ID16737 Rev 4 29/70 Functional description 6.12 L6470 Reset and standby The device can be reset and put into Standby mode through a dedicated pin. When the STBY\RST pin is driven low, the bridges are left open (High Z state), the internal charge pump is stopped, the SPI interface and control logic are disabled and the internal 3 V voltage regulator maximum output current is reduced to IREG,STBY; as a result, the L6470 heavily reduces the power consumption. At the same time the register values are reset to default and all protection functions are disabled. STBY\RST input must be forced low at least for tSTBY,min in order to ensure the complete switch to Standby mode. On exiting Standby mode, as well as for IC power-up, a delay of up to tlogicwu must be given before applying a new command to allow proper oscillator and logic startup and a delay of up to tcpwu must be given to allow the charge pump startup. On exiting Standby mode, the bridges are disabled (HiZ flag high) and any motion command makes the device exit High Z state (HardStop and SoftStop included). Attention: It is not recommended to reset the device when outputs are active. The device should be switched to high impedance state before being reset. 6.13 External switch (SW pin) The SW input is internally pulled up to VDD and detects if the pin is open or connected to ground (see Figure 13). The SW_F bit of the STATUS register indicates if the switch is open (‘0’) or closed (‘1’) (see Section 9.1.22); the bit value is refreshed at every system clock cycle (125 ns). The SW_EVN flag of the STATUS register is raised when a switch turn-on event (SW input falling edge) is detected (see Section 9.1.22). A GetStatus command releases the SW_EVN flag (see Section 9.2.20). By default, a switch turn-on event causes a HardStop interrupt (SW_MODE bit of CONFIG register set to ‘0’). Otherwise (SW_MODE bit of CONFIG register set to ‘1’), switch input events do not cause interrupts and the switch status information is at the user’s disposal (see Table 34, Section 9.1.22). The switch input may be used by the GoUntil and ReleaseSW commands as described in Section 9.2.10 and 9.2.11. If the SW input is not used, it should be connected to VDD. 30/70 Doc ID16737 Rev 4 L6470 Functional description Figure 13. External switch connection 6$$ %XTERNAL 3WITCH 37 !-V 6.14 Programmable DMOS slew rate, deadtime and blanking time Using the POW_SR parameter in the CONFIG register, it is possible to set the commutation speed of the power bridges output (see Table 26, Section 9.1.21). 6.15 Integrated analog-to-digital converter The L6470 integrates an NADC bit ramp-compare analog-to-digital converter with a reference voltage equal to VREG. The analog-to-digital converter input is available through the ADCIN pin and the conversion result is available in the ADC_OUT register (see Section 9.1.16). Sampling frequency is equal to the programmed PWM frequency. The ADC_OUT value can be used for motor supply voltage compensation or can be at the user’s disposal. 6.16 Internal voltage regulator The L6470 integrates a voltage regulator which generates a 3 V voltage starting from the motor power supply (VSA and VSB). In order to make the voltage regulator stable, at least 22 µF should be connected between the VREG pin and ground (suggested value is 47 µF). The internal voltage regulator can be used to supply the VDD pin in order to make the device digital output range 3.3 V compatible (Figure 14). A digital output range, 5 V compatible, may be obtained connecting the VDD pin to an external 5 V voltage source. In both cases, a 10 µF capacitance should be connected to the VDD pin in order to obtain a correct operation. The internal voltage regulator is able to supply a current up to IREG,MAX, internal logic consumption included (Ilogic). When the device is in Standby mode, the maximum current that can be supplied is IREG, STBY, internal consumption included (Ilogic, STBY). If an external 3.3 V regulated voltage is available, it can be applied to the VREG pin in order to supply all the internal logic and to avoid power dissipation of the internal 3 V voltage regulator (Figure 14). The external voltage regulator should never sink current from the VREG pin. Doc ID16737 Rev 4 31/70 Functional description L6470 Figure 14. Internal 3 V linear regulator VBAT Vs Vs 3V VDD VREG 3.3V REG. VDD µC VSA VSB IC DGND VDD VSA VSB IC AGND Logig supplied by INTERNAL voltage regulator 6.17 VREG DGND AGND Logig supplied by EXTERNAL voltage regulator BUSY\SYNC pin This pin is an open drain output which can be used as the busy flag or synchronization signal according to the SYNC_EN bit value (STEP_MODE register). 6.17.1 BUSY operation mode The pin works as busy signal when the SYNC_EN bit is set low (default condition). In this mode the output is forced low while a constant speed, absolute positioning or motion command is under execution. The BUSY pin is released when the command has been executed (target speed or target position reached). The STATUS register includes a BUSY flag that is the BUSY pin mirror (see Section 9.1.22). In the case of daisy chain configuration, BUSY pins of different ICs can be hard-wired to save host controller GPIOs. 6.17.2 SYNC operation mode The pin works as synchronization signal when the SYNC_EN bit is set high. In this mode a step-clock signal is provided on the output according to a SYNC_SEL and STEP_SEL parameter combination (see Section 9.1.19). 32/70 Doc ID16737 Rev 4 L6470 6.18 Functional description FLAG pin By default, an internal open drain transistor pulls the FLAG pin to ground when at least one of the following conditions occurs: ● Power-up or standby/reset exit ● Stall detection on A bridge ● Stall detection on B bridge ● Overcurrent detection ● Thermal warning ● Thermal shutdown ● UVLO ● Switch turn-on event ● Wrong command ● Non-performable command. It is possible to mask one or more alarm conditions by programming the ALARM_EN register (see Section 9.1.20, Table 21). If the corresponding bit of the ALARM_EN register is low, the alarm condition is masked and it does not cause a FLAG pin transition; all other actions imposed by alarm conditions are performed anyway. In the case of daisy chain configuration, FLAG pins of different ICs can be or-wired to save host controller GPIOs. Doc ID16737 Rev 4 33/70 Phase current control 7 L6470 Phase current control The L6470 controls the phase current applying a sinusoidal voltage to motor windings. Phase current amplitude is not directly controlled but depends on phase voltage amplitude, load torque, motor electrical characteristics and rotation speed. Sinewave amplitude is proportional to the motor supply voltage multiplied by a coefficient (KVAL). KVAL ranges from 0 to 100% and the sinewave amplitude can be obtained through the following formula: Equation 1 V OUT = V S ⋅ KVAL Different KVAL values can be programmed for acceleration, deceleration and constant speed phases and when the motor is stopped (HOLD phase) through the KVAL_ACC, KVAL_DEC, KVAL_RUN and KVAL_HOLD registers (see Section 9.1.10). KVAL value is calculated according to the following formula: Equation 2 KVAL = [ ( K VAL_X + BEMF_COMP ) × VSCOMP × K_THERM ] × microstep where KVAL_X is the starting KVAL value programmed for present motion phase (KVAL_ACC, KVAL_DEC, KVAL_RUN or KVAL_HOLD), BEMF_COMP is the BEMF compensation curve value, VSCOMP and K_THERM are the motor supply voltage and winding resistance compensation factors and microstep is the current microstep value (fraction of target peak current). The L6470 offers various methods to guarantee a stable current value, allowing the compensation of: 7.1 ● low speed optimization (Section 7.3 7.3) ● back electromotive force value (Section 7.4 7.4) ● motor supply voltage variation (Section 7.5 7.5) ● windings resistance variation (Section 7.67.6). PWM sinewave generators The two voltage sinewaves applied to the stepper motor phases are generated by two PWM modulators. The PWM frequency (fPWM) is proportional to the oscillator frequency (fOSC) and can be obtained through the following formula: Equation 3 f OSC fPWM = --------------------- ⋅ m 512 ⋅ N 'N' is the integer division factor and 'm' is the multiplication factor. 'N' and 'm' values can be programmed by the F_PWM_INT and F_PWM_DEC parameters in the CONFIG register (see Table 28 and Table 29, Section 9.1.21). Available PWM frequencies are listed in Section 9.1.21 from Table 30 to Table 33. 34/70 Doc ID16737 Rev 4 L6470 7.2 Phase current control Sensorless stall detection Depending on motor speed and load angle characteristics, the L6470 offers a motor stall condition detection using a programmable current comparator. When a stall event occurs, the respective flag (STEP_LOSS_A or STEP_LOSS_B) is forced low until a GetStaus command or a system reset occurs (see Section 9.2.20). 7.3 Low speed optimization When the motor is driven at a very low speed using a small driving voltage, the resulting phase current can be distorted. As a consequence, the motor position is different from the ideal one (see Figure 15). The L6470 implements a low speed optimization in order to remove this effect. Figure 15. Current distortion and compensation 7ITHOUTLOWSPEEDOPTIMIZAZION )PHASE 7ITHLOWSPEEDOPTIMIZAZION )PHASE #URRENTDISTORTIONISHEAVILY REDUCED !-6 The optimization can be enabled setting high the LSPD_OPT bit in the MIN_SPEED register (see Section 9.1.8) and is active in a speed range from zero to MIN_SPEED. When low speed optimization is enabled, speed profile minimum speed is forced to zero. Doc ID16737 Rev 4 35/70 Phase current control 7.4 L6470 BEMF compensation Using the speed information, a compensation curve is added to the amplitude of the voltage waveform applied to the motor winding in order to compensate the BEMF variations during acceleration and deceleration (see Figure 16). The compensation curve is approximated by a stacked line with a starting slope (ST_SLP) when speed is lower than a programmable threshold speed (INT_SPEED) and a fine slope (FN_SLP_ACC and FN_SLP_DEC) when speed is greater than the threshold speed (see Section 9.1.11, Section 9.1.12, Section 9.1.13 and Section 9.1.14). Figure 16. BEMF compensation curve #OMPENSATION VALUE &.?3,0?!## &.?3,0?$%# 34?3,0 ).4?30%%$ 3PEED !-V To obtain different current values during acceleration and deceleration phases, two different final slope values, and consequently two different compensation curves, can be programmed. The acceleration compensation curve is applied when the motor runs. No BEMF compensation is applied when the motor is stopped. 7.5 Motor supply voltage compensation The sinewave amplitude generated by the PWM modulators is directly proportional to the motor supply voltage (VS). When the motor supply voltage is different from its nominal value, the motor phases are driven with an incorrect voltage. The L6470 can compensate motor supply voltage variations in order to avoid this effect. The motor supply voltage should be connected to the integrated ADC input through a resistor divider in order to obtain VREG/2 voltage at the ADCIN pin when VS is at its nominal value (see Figure 17). The ADC input is sampled at fS frequency, which is equal to PWM frequency. 36/70 Doc ID16737 Rev 4 L6470 Phase current control Figure 17. Motor supply voltage compensation circuit 63 62%' 2! !$#). 6!$#).63X2"2!2" !$# !$#?/54 2" F07!-V Motor supply voltage compensation can be enabled setting high the EN_VSCOMP bit of the CONFIG register (see Table 22, Section 9.1.21). If the EN_VSCOMP bit is low, the compensation is disabled and the internal analog-to-digital converter is at the user’s disposal; sampling rate is always equal to PWM frequency. 7.6 Winding resistance thermal drift compensation The higher the winding resistance, the greater the voltage to be applied in order to obtain the same phase current. The L6470 integrates a register (K_THERM) which can be used to compensate phase resistance increment due to temperature rising. The value in the K_THERM register (see Section 9.1.15) multiplies the duty cycle value allowing a higher phase resistance value to be faced. The compensation algorithm and the eventual motor temperature measurement should be implemented by microcontroller firmware. Doc ID16737 Rev 4 37/70 Serial interface 8 L6470 Serial interface The integrated 8-bit serial peripheral interface (SPI) is used for a synchronous serial communication between the host microprocessor (always master) and the L6470 (always slave). The SPI uses chip select (CS), serial clock (CK), serial data input (SDI) and serial data output (SDO) pins. When CS is high, the device is unselected and the SDO line is inactive (high-impedance). The communication starts when CS is forced low. The CK line is used for synchronization of data communication. All commands and data bytes are shifted into the device through the SDI input, most significant bit first. The SDI is sampled on the rising edges of the CK. All output data bytes are shifted out of the device through the SDO output, most significant bit first. The SDO is latched on the falling edges of the CK. When a return value from the device is not available, an all zero byte is sent. After each byte transmission the CS input must be raised and be kept high for at least tdisCS in order to allow the device to decode the received command and put the return value into the SHIFT register. All timing requirements are shown in Figure 18 (see Section 3: Electrical characteristics for values). Multiple devices can be connected in daisy chain configuration, as shown in Figure 19. Figure 18. SPI timings diagram #3 TDIS#3 TSET#3 TR#+ TH#+ TF#+ TL#+ #+ TEN3$/ TSET3$) THOL#3 THOL3$) . -3" 3$) (I: -3" ,3" TV3$/ THOL3$/ 3$/ . TDIS3$/ . . ,3" -3" !-V 38/70 Doc ID16737 Rev 4 L6470 Serial interface Figure 19. Daisy chain configuration $%6 #3 #3 #+ #+ (/34 3$/ - 3$)- 3$) 3$/ $%6 #3 #+ (/3430)SIGNALS 3$) 3$/ #3 3$/- "YTE. "YTE. "YTE "YTE. 3$)- "YTE. "YTE. "YTE "YTE. $%6. #3 #+ 3$) 3$/ !-V Doc ID16737 Rev 4 39/70 Programming manual L6470 9 Programming manual 9.1 Registers and flags description The following is a map of the user registers available (detailed description in respective paragraphs): Table 9. Address [Hex] Registers map Register name h01 ABS_POS h02 EL_POS h03 h04 Register function Len. [bit] Current position 22 Electrical position 9 MARK Mark position SPEED Current speed Reset Reset Hex value 000000 0 000 Remarks (1) R, WS 0 R, WS 22 000000 0 R, WR 20 00000 0 step/tick (0 step/s) step/tick2 (2008 R h05 ACC Acceleration 12 08A 125.5e-12 step/s2) h06 DEC Deceleration 12 08A 125.5e-12 step/tick2 (2008 step/s2) R, WS h07 MAX_SPEED Maximum speed 10 041 248e-6 step/tick (991.8 step/s) R, WR h08 MIN_SPEED Minimum speed 13 000 0 step/tick (0 step/s) R, WS h15 FS_SPD Full-step speed 10 027 150.7e-6 step/tick (602.7 step/s) R, WR h09 KVAL_HOLD Holding KVAL 8 29 0.16·VS R, WR h0A KVAL_RUN Constant speed KVAL 8 29 0.16·VS R, WR h0B KVAL_ACC Acceleration starting KVAL 8 29 0.16·VS R, WR h0C KVAL_DEC Deceleration starting KVAL 8 29 0.16·VS R, WR h0D INT_SPEED Intersect speed 14 0408 15.4e-6 step/tick (61.5 step/s) R, WH h0E ST_SLP Start slope 8 19 0.038% s/step R, WH h0F FN_SLP_ACC Acceleration final slope 8 29 0.063% s/step R, WH h10 FN_SLP_DEC Deceleration final slope 8 29 0.063% s/step R, WH h11 K_THERM Thermal compensation factor 4 0 1.0 R, WR h12 ADC_OUT ADC output 5 XX (2) h13 OCD_TH OCD threshold 4 8 3.38A R, WR h14 STALL_TH STALL threshold 7 40 2.03A R, WR h16 STEP_MODE Step mode 8 7 128 microsteps R, WH h17 ALARM_EN Alarm enable 8 FF All alarms enabled R, WS 40/70 Doc ID16737 Rev 4 R, WS R L6470 Table 9. Address [Hex] Programming manual Registers map (continued) Register name Register function Len. [bit] Reset Reset Hex value Internal oscillator, 2 MHz OSCOUT clock, supply voltage compensation disabled, overcurrent shutdown enabled, slew rate = 290 V/µs PWM frequency = 15.6 kHz. h18 CONFIG IC configuration 16 2E88 h19 STATUS Status 16 XXXX (2) h1A RESERVED Reserved address h1B RESERVED Reserved address Remarks (1) High impedance state, UVLO/Reset flag set. R, WH R 1. R: readable, WH: writable only when outputs are in high impedance, WS: writable only when motor is stopped, WR: always writable. 2. According to startup conditions. 9.1.1 ABS_POS The ABS_POS register contains the current motor absolute position in agreement with the selected step mode; the stored value unit is equal to the selected step mode (full, half, quarter, etc.). The value is in 2's complement format and it ranges from -221 to +221-1. At power-on the register is initialized to “0” (HOME position). Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.2 EL_POS The EL_POS register contains the current electrical position of the motor. The two MSbits indicate the current step and the other bits indicate the current microstep (expressed in step/128) within the step. Table 10. Bit 8 EL_POS register Bit 7 Bit 6 Bit 5 Bit 4 STEP Bit 3 Bit 2 Bit 1 Bit 0 MICROSTEP When the EL_POS register is written by the user, the new electrical position is instantly imposed. When the EL_POS register is written, its value must be masked in order to match with the step mode selected in the STEP_MODE register in order to avoid a wrong microstep value generation (see Section 9.1.19); otherwise the resulting microstep sequence is incorrect. Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). Doc ID16737 Rev 4 41/70 Programming manual 9.1.3 L6470 MARK The MARK register contains an absolute position called MARK according to the selected step mode; the stored value unit is equal to the selected step mode (full, half, quarter, etc.). It is in 2's complement format and it ranges from -221 to +221-1. 9.1.4 SPEED The SPEED register contains the current motor speed, expressed in step/tick (format unsigned fixed point 0.28). In order to convert the SPEED value in step/s, the following formula can be used: Equation 4 – 28 ⋅ 2 --------------------------------------[ step/s ] = SPEED tick where SPEED is the integer number stored in the register and tick is 250 ns. The available range is from 0 to 15625 step/s with a resolution of 0.015 step/s. Note: The range effectively available to the user is limited by the MAX_SPEED parameter. Any attempt to write the register causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.5 ACC The ACC register contains the speed profile acceleration expressed in step/tick2 (format unsigned fixed point 0.40). In order to convert ACC value in step/s2, the following formula can be used: Equation 5 – 40 2 ⋅ 2 [ step/s ] = ACC ------------------------------2 tick where ACC is the integer number stored in the register and tick is 250 ns. The available range is from 14.55 to 59590 step/s2 with a resolution of 14.55 step/s2. When the ACC value is set to 0xFFF, the device works in infinite acceleration mode. Any attempt to write to the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.6 DEC The DEC register contains the speed profile deceleration expressed in step/tick2 (format unsigned fixed point 0.40). In order to convert DEC value in step/s2, the following formula can be used: Equation 6 – 40 2 DEC ⋅ 2 [ step/s ] = ------------------------------2 tick 42/70 Doc ID16737 Rev 4 L6470 Programming manual where DEC is the integer number stored in the register and tick is 250 ns. The available range is from 14.55 to 59590 step/s2 with a resolution of 14.55 step/s2. When the device is working in infinite acceleration mode, this value is ignored. Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.7 MAX_SPEED The MAX_SPEED register contains the speed profile maximum speed expressed in step/tick (format unsigned fixed point 0.18). In order to convert it in step/s, the following formula can be used: Equation 7 – 18 MAX_SPEED ⋅ 2 [ step/s ] = -------------------------------------------------------tick where MAX_SPEED is the integer number stored in the register and tick is 250 ns. The available range is from 15.25 to 15610 step/s with a resolution of 15.25 step/s. 9.1.8 MIN_SPEED The MIN_SPEED register contains the following parameters: Table 11. MIN_SPEED register Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 LSPD_OPT MIN_SPEED The MIN_SPEED parameter contains the speed profile minimum speed. Its value is expressed in step/tick and to convert it in step/s, the following formula can be used: Equation 8 – 24 ⋅ 2 [ step/s ] = MIN_SPEED ----------------------------------------------------tick where MIN_SPEED is the integer number stored in the register and tick is the ramp 250 ns. The available range is from 0 to 976.3 step/s with a resolution of 0.238 step/s. When the LSPD_OPT bit is set high, the low speed optimization feature is enabled and the MIN_SPEED value indicates the speed threshold below which the compensation works. In this case the minimum speed of the speed profile is set to zero. An attempt to write the register when the motor is running causes the NOTPERF_CMD flag to rise. 9.1.9 FS_SPD The FS_SPD register contains the threshold speed. When the actual speed exceeds this value, the step mode is automatically switched to full-step two-phase on. Its value is Doc ID16737 Rev 4 43/70 Programming manual L6470 expressed in step/tick (format unsigned fixed point 0.18) and to convert it in step/s, the following formula can be used. Equation 9 – 18 ( FS_SPD + 0.5 ) ⋅ 2 [ step/s ] = -------------------------------------------------------------tick If the FS_SPD value is set to hFF (max.) the system always works in microstepping mode (SPEED must go beyond the threshold to switch to Full-step mode). Setting FS_SPD to zero does not have the same effect as setting Step mode to full-step two-phase on: the zero FS_SPD value is equivalent to a speed threshold of about 7.63 step/s. The available range is from 7.63 to 15625 step/s with a resolution of 15.25 step/s. 9.1.10 KVAL_HOLD, KVAL_RUN, KVAL_ACC and KVAL_DEC The KVAL_HOLD register contains the KVAL value that is assigned to the PWM modulators when the motor is stopped (compensation excluded). The KVAL_RUN register contains the KVAL value that is assigned to the PWM modulators when the motor is running at constant speed (compensation excluded). The KVAL_ACC register contains the starting KVAL value that can be assigned to the PWM modulators during acceleration (compensation excluded). The KVAL_DEC register contains the starting KVAL value that can be assigned to the PWM modulators during deceleration (compensation excluded). The available range is from 0 to 0.996 x VS with a resolution of 0.004 x VS, as shown in Table 12. Table 12. Voltage amplitude regulation registers KVAL_X [7..0] 9.1.11 Output voltage 0 0 0 0 0 0 0 1 VS x (1/256) … 0 … 0 … 0 … 0 … 0 … 0 … 0 … 0 … 0 1 1 1 1 1 1 1 0 VS x (254/256) 1 1 1 1 1 1 1 1 VS x (255/256) INT_SPEED The INT_SPEED register contains the speed value at which the BEMF compensation curve changes slope (see Section 7.4). Its value is expressed in step/tick and to convert it in step/s, the following formula can be used: Equation 10 – 26 INT – SPEED ⋅ 2 [ step ⁄ s ] = ----------------------------------------------------tick where INT_SPEED is the integer number stored in the register and tick is 250 ns. 44/70 Doc ID16737 Rev 4 L6470 Programming manual The available range is from 0 to 976.5 step/s with a resolution of 0.0596 step/s. Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.12 ST_SLP The ST_SLP register contains the BEMF compensation curve slope that is used when the speed is lower than the intersect speed (see Section 7.4). Its value is expressed in s/step and the available range is from 0 to 0.004 with a resolution of 0.000015. When ST_SLP, FN_SLP_ACC and FN_SLP_DEC parameters are set to zero, no BEMF compensation is performed. Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.13 FN_SLP_ACC The FN_SLP_ACC register contains the BEMF compensation curve slope that is used when the speed is greater than the intersect speed during acceleration (see Section 7.47.4). Its value is expressed in s/step and the available range is from 0 to 0.004 with a resolution of 0.000015. When ST_SLP, FN_SLP_ACC and FN_SLP_DEC parameters are set to zero, no BEMF compensation is performed. Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.14 FN_SLP_DEC The FN_SLP_DEC register contains the BEMF compensation curve slope that is used when the speed is greater than the intersect speed during deceleration (see Section 7.47.4). Its value is expressed in s/step and the available range is from 0 to 0.004 with a resolution of 0.000015. When ST_SLP, FN_SLP_ACC and FN_SLP_DEC parameters are set to zero, no BEMF compensation is performed. Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). K_THERM The K_THERM register contains the value used by the winding resistance thermal drift compensation system (see Section 7.6). The available range is from 1 to 1.46875 with a resolution of 0.03125, as shown in Table 13. Table 13. Winding resistance thermal drift compensation coefficient 0 0 0 0 1 0 0 0 1 1.03125 … … … Compensation coeff. … K_THERM [3..0] … 9.1.15 Doc ID16737 Rev 4 45/70 Programming manual L6470 Table 13. Winding resistance thermal drift compensation coefficient (continued) K_THERM [3..0] 9.1.16 Compensation coeff. 1 1 1 0 1.4375 1 1 1 1 1.46875 ADC_OUT The ADC_OUT register contains the result of the analog-to-digital conversion of the ADCIN pin voltage; the result is available even if the supply voltage compensation is disabled. Any attempt to write to the register causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). Table 14. 9.1.17 ADC_OUT value and motor supply voltage compensation feature ADC_OUT Compensation coefficient VS VADCIN/VREG Greater than VS,nom + 50% > 24/32 1 1 X X X 0.65625 VS,nom + 50% 24/32 1 1 0 0 0 0.65625 … 1 … … 0 … … 0 … … 0 … … 0 … … 1 … … 16/32 … VS,nom … … [4..0] VS,nom – 50% 8/32 0 1 0 0 0 1.968875 Lower than VS,nom – 50% < 8/32 0 0 X X X 1.968875 OCD_TH The OCD_TH register contains the overcurrent threshold value (see Section 6.9). The available range is from 375 mA to 6 A, in steps of 375 mA, as shown in Table 15. Table 15. Overcurrent detection threshold OCD_TH [3..0] 9.1.18 Overcurrent detection threshold 0 0 0 0 375 mA 0 0 0 1 750 mA … … … … … 1 1 1 0 5.625 A 1 1 1 1 6A STALL_TH The STALL_TH register contains the stall detection threshold value (see Section 7.2). The available range is from 31.25 mA to 4 A with a resolution of 31.25 mA. 46/70 Doc ID16737 Rev 4 L6470 Programming manual Table 16. Stall detection threshold STALL_th [6..0] 9.1.19 Stall detection threshold 0 0 0 0 0 0 0 31.25 mA 0 0 0 0 0 0 1 62.5 mA … … … … … … … … 1 1 1 1 1 1 0 3.969 A 1 1 1 1 1 1 1 4A STEP_MODE The STEP_MODE register has the following structure: Table 17. Bit 7 STEP_MODE register Bit 6 Bit 5 SYNC_EN Bit 4 Bit 3 SYNC_SEL 0 (1) Bit 2 Bit 1 Bit 0 STEP_SEL 1. When the register is written, this bit should be set to 0. The STEP_SEL parameter selects one of eight possible stepping modes: Table 18. Step mode selection STEP_SEL[2..0] Step mode 0 0 0 Full-step 0 0 1 Half-step 0 1 0 1/4 microstep 0 1 1 1/8 microstep 1 0 0 1/16 microstep 1 0 1 1/32 microstep 1 1 0 1/64 microstep 1 1 1 1/128 microstep Every time the step mode is changed, the electrical position (i.e. the point of microstepping sinewave that is generated) is reset to the first microstep. Warning: Every time STEP_SEL is changed, the value in the ABS_POS register loses meaning and should be reset. Any attempt to write the register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). Doc ID16737 Rev 4 47/70 Programming manual L6470 When the SYNC_EN bit is set low, BUSY/SYNC output is forced low during command execution, otherwise, when the SYNC_EN bit is set high, BUSY/SYNC output provides a clock signal according to the SYNC_SEL parameter. Table 19. SYNC output frequency SYNC_SEL STEP_SEL (fFS is the full-step frequency) 000 001 010 011 100 101 110 111 000 fFS /2 fFS /2 fFS /2 fFS /2 fFS /2 fFS /2 fFS /2 fFS /2 001 NA fFS fFS fFS fFS fFS fFS fFS 010 NA NA 2· fFS 2· fFS 2· fFS 2· fFS 2· fFS 2· fFS 011 NA NA NA 4· fFS 4· fFS 4· fFS 4· fFS 4· fFS 100 NA NA NA NA 8· fFS 8· fFS 8· fFS 8· fFS 101 NA NA NA NA NA 16· fFS 16· fFS 16· fFS 110 NA NA NA NA NA NA 32· fFS 32· fFS 111 NA NA NA NA NA NA NA 64· fFS The synchronization signal is obtained starting from electrical position information (EL_POS register) according to Table 10: Table 20. SYNC signal source SYNC_SEL[2..0] 9.1.20 Source 0 0 0 EL_POS[7] 0 0 1 EL_POS[6] 0 1 0 EL_POS[5] 0 1 1 EL_POS[4] 1 0 0 EL_POS[3] 1 0 1 EL_POS[2] 1 1 0 EL_POS[1] 1 1 1 EL_POS[0] ALARM_EN The ALARM_EN register allows the selection of which alarm signals are used to generate the FLAG output. If the respective bit of the ALARM_EN register is set high, the alarm condition forces the FLAG pin output down. 48/70 Doc ID16737 Rev 4 L6470 Programming manual Table 21. 9.1.21 ALARM_EN register ALARM_EN bit Alarm condition 0 (LSB) Overcurrent 1 Thermal shutdown 2 Thermal warning 3 Undervoltage 4 Stall detection (Bridge A) 5 Stall detection (Bridge B) 6 Switch turn-on event 7 (MSB) Wrong or non-performable command CONFIG The CONFIG register has the following structure: Table 22. CONFIG register Bit 15 Bit 14 Bit 13 Bit 12 F_PWM_INT Bit 7 OC_SD Bit 6 Bit 11 Bit 10 F_PWM_DEC Bit 5 Bit 4 Bit 3 RESERVED EN_VSCOMP SW_MODE EXT_CLK Bit 9 Bit 8 POW_SR Bit 2 Bit 1 Bit 0 OSC_SEL The OSC_SEL and EXT_CLK bits set the system clock source: Table 23. Oscillator management EXT_C LK OSC_SEL[2..0] Clock source OSCIN OSCOUT Internal oscillator: 16 MHz Unused Unused 0 0 0 0 0 0 0 1 0 0 1 0 0 0 1 1 1 0 0 0 Internal oscillator: 16 MHz Unused Supplies a 2-MHz clock 1 0 0 1 Internal oscillator: 16 MHz Unused Supplies a 4-MHz clock 1 0 1 0 Internal oscillator: 16 MHz Unused Supplies an 8-MHz clock 1 0 1 1 Internal oscillator: 16 MHz Unused Supplies a 16-MHz clock Doc ID16737 Rev 4 49/70 Programming manual Table 23. L6470 Oscillator management (continued) EXT_C LK OSC_SEL[2..0] Clock source OSCIN OSCOUT 0 1 0 0 External crystal or resonator: 8 MHz Crystal/resonator driving Crystal/resonator driving 0 1 0 1 External crystal or resonator: 16 MHz Crystal/resonator driving Crystal/resonator driving 0 1 1 0 External crystal or resonator: 24 MHz Crystal/resonator driving Crystal/resonator driving 0 1 1 1 External crystal or resonator: 32 MHz Crystal/resonator driving Crystal/resonator driving 1 1 0 0 Ext clock source: 8 MHz (Crystal/resonator driver disabled) Clock source Supplies inverted OSCIN signal 1 1 0 1 Ext clock source: 16 MHz (Crystal/resonator driver disabled) Clock source Supplies inverted OSCIN signal 1 1 1 0 Ext clock source: 24 MHz (Crystal/resonator driver disabled) Clock source Supplies inverted OSCIN signal 1 1 1 1 Ext clock source: 32 MHz (Crystal/resonator driver disabled) Clock source Supplies inverted OSCIN signal The SW_MODE bit sets the external switch to act as HardStop interrupt or not: Table 24. External switch hard stop interrupt mode SW_MODE Switch mode 0 HardStop interrupt 1 User disposal The OC_SD bit sets whether an overcurrent event causes or not the bridges to turn off; the OCD flag in the STATUS register is forced low anyway: Table 25. Overcurrent event OC_SD Overcurrent event 1 Bridges shut down 0 Bridges do not shut down The POW_SR bits set the slew rate value of power bridge output: 50/70 Doc ID16737 Rev 4 L6470 Programming manual Table 26. Programmable power bridge output slew rate values POW_SR Output slew rate (1) [1..0] [V/µs] 0 0 180 0 1 180 1 0 290 1 1 530 1. See SRout_r and SRout_f parameters in Table 5 for details. The EN_VSCOMP bit sets whether the motor supply voltage compensation is enabled or not. Table 27. Motor supply voltage compensation enable EN_VSCOMP Motor supply voltage compensation 0 Disabled 1 Enabled The F_PWM_INT bits set the integer division factor of PWM frequency generation. Table 28. PWM frequency: integer division factor F_PWM_INT [2..0] Integer division factor 0 0 0 1 0 0 1 2 0 1 0 3 0 1 1 4 1 0 0 5 1 0 1 6 1 1 0 7 1 1 1 The F_PWM_DEC bits set the multiplication factor of PWM frequency generation. Doc ID16737 Rev 4 51/70 Programming manual Table 29. L6470 PWM frequency: multiplication factor F_PWM_DEC [2..0] Multiplication factor 0 0 0 0.625 0 0 1 0.75 0 1 0 0.875 0 1 1 1 1 0 0 1.25 1 0 1 1.5 1 1 0 1.75 1 1 1 2 In the following tables all available PWM frequencies are listed according to oscillator frequency, F_PWM_INT and F_PWM_DEC values (CONFIG register OSC_SEL parameter must be correctly programmed). Table 30. Available PWM frequencies [kHz]: 8-MHz oscillator frequency F_PWM_DEC F_PWM_ INT 000 001 010 011 100 101 110 111 000 9.8 11.7 13.7 15.6 19.5 23.4 27.3 31.3 001 4.9 5.9 6.8 7.8 9.8 11.7 13.7 15.6 010 3.3 3.9 4.6 5.2 6.5 7.8 9.1 10.4 011 2.4 2.9 3.4 3.9 4.9 5.9 6.8 7.8 100 2.0 2.3 2.7 3.1 3.9 4.7 5.5 6.3 101 1.6 2.0 2.3 2.6 3.3 3.9 4.6 5.2 110 1.4 1.7 2.0 2.2 2.8 3.3 3.9 4.5 Table 31. Available PWM frequencies [kHz]: 16-MHz oscillator frequency F_PWM_DEC 52/70 F_PWM_INT 000 001 010 011 100 101 110 111 000 19.5 23.4 27.3 31.3 39.1 46.9 54.7 62.5 001 9.8 11.7 13.7 15.6 19.5 23.4 27.3 31.3 010 6.5 7.8 9.1 10.4 13.0 15.6 18.2 20.8 Doc ID16737 Rev 4 L6470 Programming manual Table 31. Available PWM frequencies [kHz]: 16-MHz oscillator frequency F_PWM_DEC F_PWM_INT 000 001 010 011 100 101 110 111 011 4.9 5.9 6.8 7.8 9.8 11.7 13.7 15.6 100 3.9 4.7 5.5 6.3 7.8 9.4 10.9 12.5 101 3.3 3.9 4.6 5.2 6.5 7.8 9.1 10.4 110 2.8 3.3 3.9 4.5 5.6 6.7 7.8 8.9 Table 32. Available PWM frequencies [kHz]: 24-MHz oscillator frequency F_PWM_DEC F_PWM_INT 000 001 010 011 100 101 110 111 000 29.3 35.2 41.0 46.9 58.6 70.3 82.0 93.8 001 14.6 17.6 20.5 23.4 29.3 35.2 41.0 46.9 010 9.8 11.7 13.7 15.6 19.5 23.4 27.3 31.3 011 7.3 8.8 10.3 11.7 14.6 17.6 20.5 23.4 100 5.9 7.0 8.2 9.4 11.7 14.1 16.4 18.8 101 4.9 5.9 6.8 7.8 9.8 11.7 13.7 15.6 110 4.2 5.0 5.9 6.7 8.4 10.0 11.7 13.4 Table 33. Available PWM frequencies [kHz]: 32-MHz oscillator frequency F_PWM_DEC F_PWM_ INT 000 001 010 011 100 101 110 111 000 39.1 46.9 54.7 62.5 78.1 93.8 109.4 125.0 001 19.5 23.4 27.3 31.3 39.1 46.9 54.7 62.5 010 13.0 15.6 18.2 20.8 26.0 31.3 36.5 41.7 011 9.8 11.7 13.7 15.6 19.5 23.4 27.3 31.3 100 7.8 9.4 10.9 12.5 15.6 18.8 21.9 25.0 101 6.5 7.8 9.1 10.4 13.0 15.6 18.2 20.8 110 5.6 6.7 7.8 8.9 11.2 13.4 15.6 17.9 Doc ID16737 Rev 4 53/70 Programming manual L6470 Any attempt to write the CONFIG register when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.1.22 STATUS Table 34. STATUS register Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 SCK_MOD STEP_LOSS_B STEP_LOSS_A OCD TH_SD TH_WRN UVLO WRONG_CMD Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 DIR SW_EVN SW_F BUSY HiZ NOTPERF_CMD MOT_STATUS When the HiZ flag is high, it indicates that the bridges are in high impedance state. Any motion command makes the device exit from High Z state (HardStop and SoftStop included), unless error flags forcing a High Z state are active. The UVLO flag is active low and is set by an undervoltage lockout or reset events (power-up included). The TH_WRN, TH_SD, OCD flags are active low and indicate, respectively, thermal warning, thermal shutdown and overcurrent detection events. STEP_LOSS_A and STEP_LOSS_B flags are forced low when a stall is detected on bridge A or bridge B respectively. The NOTPERF_CMD and WRONG_CMD flags are active high and indicate, respectively, that the command received by SPI cannot be performed or does not exist at all. The SW_F flag reports the SW input status (low for open and high for closed). The SW_EVN flag is active high and indicates a switch turn-on event (SW input falling edge). The UVLO, TH_WRN, TH_SD, OCD, STEP_LOSS_A, STEP_LOSS_B, NOTPERF_CMD, WRONG_CMD and SW_EVN flags are latched: when the respective conditions make them active (low or high), they remain in that state until a GetStatus command is sent to the IC. The BUSY bit reflects the BUSY pin status. The BUSY flag is low when a constant speed, positioning or motion command is under execution and is released (high) after the command has been completed. The SCK_MOD bit is an active high flag indicating that the device is working in Step-clock mode. In this case the step-clock signal should be provided through the STCK input pin. The DIR bit indicates the current motor direction: Table 35. STATUS register DIR bit DIR Motor direction 1 Forward 0 Reverse MOT_STATUS indicates the current motor status: 54/70 Doc ID16737 Rev 4 L6470 Programming manual Table 36. STATUS register MOT_STATE bits MOT_STATUS Motor status 0 0 Stopped 0 1 Acceleration 1 0 Deceleration 1 1 Constant speed Any attempt to write to the register causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.2 Application commands The command summary is given in Table 37. Table 37. Application commands Command binary code Command mnemonic Action [7..5] [4] 0 [3] 0 [2..1] [0] NOP 000 00 0 Nothing SetParam(PARAM,VALUE) 000 [PARAM] Writes VALUE in PARAM register GetParam(PARAM) 001 [PARAM] Returns the stored value in PARAM register Run(DIR,SPD) 010 1 0 00 DIR Sets the target speed and the motor direction StepClock(DIR) 010 1 1 00 DIR Puts the device into Step-clock mode and imposes DIR direction Move(DIR,N_STEP) 010 0 0 00 DIR Makes N_STEP (micro)steps in DIR direction (Not performable when motor is running) GoTo(ABS_POS) 011 0 0 00 0 GoTo_DIR(DIR,ABS_POS) 011 0 1 00 DIR GoUntil(ACT,DIR,SPD) 100 0 ACT 01 Performs a motion in DIR direction with speed SPD until DIR SW is closed, the ACT action is executed then a SoftStop takes place. ReleseSW(ACT, DIR) 100 1 ACT 01 Performs a motion in DIR direction at minimum speed DIR until the SW is released (open), the ACT action is executed then a HardStop takes place. GoHome 011 1 0 00 0 Brings the motor into HOME position GoMark 011 1 1 00 0 Brings the motor into MARK position ResetPos 110 1 1 00 0 Resets the ABS_POS register (set HOME position) ResetDevice 110 0 0 00 0 Device is reset to power-up conditions. SoftStop 101 1 0 00 0 Stops motor with a deceleration phase Brings motor into ABS_POS position (minimum path) Brings motor into ABS_POS position forcing DIR direction Doc ID16737 Rev 4 55/70 Programming manual Table 37. L6470 Application commands (continued) Command binary code Command mnemonic Action [7..5] [4] 9.2.1 [3] [2..1] [0] HardStop 101 1 1 00 0 Stops motor immediately SoftHiZ 101 0 0 00 0 Puts the bridges into high impedance status after a deceleration phase HardHiZ 101 0 1 00 0 Puts the bridges into high impedance status immediately GetStatus 110 1 0 00 0 Returns the STATUS register value RESERVED 111 0 1 01 1 RESERVED COMMAND RESERVED 111 1 1 00 0 RESERVED COMMAND Command management The host microcontroller can control motor motion and configure the L6470 through a complete set of commands. All commands are composed by a single byte. After the command byte, some bytes of arguments should be needed (see Figure 20). Argument length can vary from 1 to 3 bytes. Figure 20. Command with 3-byte argument 3$) FROMHOST 3$/ TOHOST #OMMANDBYTE !RGUMENTBYTE -3" !RGUMENTBYTE !RGUMENTBYTE ,3" X X X X By default, the device returns an all zero response for any received byte, the only exceptions are the GetParam and GetStatus commands. When one of these commands is received, the following response bytes represent the related register value (see Figure 21). Response length can vary from 1 to 3 bytes. Figure 21. Command with 3-byte response 3$) FROMHOST 3$/ TOHOST #OMMANDBYTE ./0 ./0 ./0 X 2ESPONSEBYTE -3" 2ESPONSEBYTE 2ESPONSEBYTE ,3" During response transmission, new commands can be sent. If a command requiring a response is sent before the previous response is completed, the response transmission is aborted and the new response is loaded into the output communication buffer (see Figure 22). 56/70 Doc ID16737 Rev 4 L6470 Programming manual Figure 22. Command response aborted 3$) FROMHOST 3$/ TOHOST #OMMAND BYTERESPEXPECTED #OMMAND NORESPEXPECTED #OMMAND BYTERESPEXPECTED #OMMAND NORESPEXPECTED #OMMAND NORESPEXPECTED X 2ESPONSEBYTE -3" 2ESPONSEBYTE 2ESPONSEBYTE -3" 2ESPONSEBYTE ,3" #OMMANDRESPONSE ISABORTED When a byte that does not correspond to a command is sent to the IC, it is ignored and the WRONG_CMD flag in the STATUS register is raised (see Section 9.1.22). 9.2.2 Nop Table 38. Nop command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 0 0 0 0 0 0 0 Bit 1 Bit 0 from host Nothing is performed. 9.2.3 SetParam (PARAM, VALUE) Table 39. SetParam command structure Bit 7 Bit 6 Bit 5 0 0 0 Bit 4 Bit 3 Bit 2 PARAM VALUE Byte 2 (if needed) from host VALUE Byte 1 (if needed) VALUE Byte 0 The SetParam command sets the PARAM register value equal to VALUE; PARAM is the respective register address listed in Table 12. The command should be followed by the new register VALUE (most significant byte first). The number of bytes making up the VALUE argument depends on the length of the target register (see Table 12). Some registers cannot be written (see Table 12); any attempt to write one of those registers causes the command to be ignored and the WRONG_CMD flag to rise at the end of the command byte as if an unknown command code were sent (see Section 9.1.22). Some registers can only be written in particular conditions (see Table 12); any attempt to write one of those registers when the conditions are not satisfied causes the command to be ignored and the NOTPERF_CMD flag to rise at the end of the last argument byte (see Section 9.1.22). Any attempt to set an inexistent register (wrong address value) causes the command to be ignored and the WRONG_CMD flag to rise at the end of the command byte as if an unknown command code were sent. Doc ID16737 Rev 4 57/70 Programming manual 9.2.4 L6470 GetParam (PARAM) Table 40. GetParam command structure Bit 7 Bit 6 Bit 5 0 0 1 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 PARAM from host ANS Byte 2 (if needed) to host ANS Byte 1 (if needed) to host ANS Byte 0 to host This command reads the current PARAM register value; PARAM is the respective register address listed in Table 12. The command response is the current value of the register (most significant byte first). The number of bytes making up the command response depends on the length of the target register (see Table 12). The returned value is the register one at the moment of GetParam command decoding. If register values change after this moment, the response is not accordingly updated. All registers can be read anytime. Any attempt to read an inexistent register (wrong address value) causes the command to be ignored and the WRONG_CMD flag to rise at the end of the command byte as if an unknown command code were sent. 9.2.5 Run (DIR, SPD) Table 41. Run command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 0 1 0 0 0 DIR X X X X SPD (Byte 2) from host from host SPD (Byte 1) from host SPD (Byte 0) from host The Run command produces a motion at SPD speed; the direction is selected by the DIR bit: '1' forward or '0' reverse. The SPD value is expressed in step/tick (format unsigned fixed point 0.28) that is the same format as the SPEED register (see Section 9.1.4). Note: The SPD value should be lower than MAX_SPEED and greater than MIN_SPEED otherwise the Run command is executed at MAX_SPEED or MIN_SPEED respectively. This command keeps the BUSY flag low until the target speed is reached. This command can be given anytime and is immediately executed. 58/70 Doc ID16737 Rev 4 L6470 9.2.6 Programming manual StepClock (DIR) Table 42. Stepclock command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 0 1 1 0 0 DIR from host The StepClock command switches the device in Step-clock mode (see Section 6.7.5) and imposes the forward (DIR = '1') or reverse (DIR = '0') direction. When the device is in Step-clock mode, the SCK_MOD flag in the STATUS register is raised and the motor is always considered stopped (see Section 6.7.5 and 9.1.22). The device exits from Step-clock mode when a constant speed, absolute positioning or motion command is sent through SPI. Motion direction is imposed by the respective StepClock command argument and can by changed by a new StepClock command without exiting Step-clock mode. Events that cause bridges to be forced into high impedance state (overtemperature, overcurrent, etc.) do not cause the device to leave Step-clock mode. The StepClock command does not force the BUSY flag low. This command can only be given when the motor is stopped. If a motion is in progress, the motor should be stopped and it is then possible to send a StepClock command. Any attempt to perform a StepClock command when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.2.7 Move (DIR, N_STEP) Table 43. Move command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 0 0 0 0 0 DIR X X N_STEP (Byte 2) from host from host N_STEP (Byte 1) from host N_STEP (Byte 0) from host The Move command produces a motion of N_STEP microsteps; the direction is selected by the DIR bit ('1' forward or '0' reverse). The N_STEP value is always in agreement with the selected step mode; the parameter value unit is equal to the selected step mode (full, half, quarter, etc.). This command keeps the BUSY flag low until the target number of steps is performed. This command can only be performed when the motor is stopped. If a motion is in progress, the motor must be stopped and it is then possible to perform a Move command. Any attempt to perform a Move command when the motor is running causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). Doc ID16737 Rev 4 59/70 Programming manual 9.2.8 L6470 GoTo (ABS_POS) Table 44. GoTo command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 1 0 0 0 0 0 X X ABS_POS (Byte 2) from host from host ABS_POS (Byte 1) from host ABS_POS (Byte 0) from host The GoTo command produces a motion to ABS_POS absolute position through the shortest path. The ABS_POS value is always in agreement with the selected step mode; the parameter value unit is equal to the selected step mode (full, half, quarter, etc.). The GoTo command keeps the BUSY flag low until the target position is reached. This command can be given only when the previous motion command has been completed (BUSY flag released). Any attempt to perform a GoTo command when a previous command is under execution (BUSY low) causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.2.9 GoTo_DIR (DIR, ABS_POS) Table 45. GoTo_DIR command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 1 0 1 0 0 DIR X X ABS_POS (Byte 2) from host from host ABS_POS (Byte 1) from host ABS_POS (Byte 0) from host The GoTo_DIR command produces a motion to ABS_POS absolute position imposing a forward (DIR = '1') or a reverse (DIR = '0') rotation. The ABS_POS value is always in agreement with the selected step mode; the parameter value unit is equal to the selected step mode (full, half, quarter, etc.). The GoTo_DIR command keeps the BUSY flag low until the target speed is reached. This command can be given only when the previous motion command has been completed (BUSY flag released). Any attempt to perform a GoTo_DIR command when a previous command is under execution (BUSY low) causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 60/70 Doc ID16737 Rev 4 L6470 9.2.10 Programming manual GoUntil (ACT, DIR, SPD) Table 46. GoUntil command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 0 0 0 ACT 0 1 DIR X X X X SPD (Byte 2) from host from host SPD (Byte 1) from host SPD (Byte 0) from host The GoUntil command produces a motion at SPD speed imposing a forward (DIR = '1') or a reverse (DIR = '0') direction. When an external switch turn-on event occurs (see Section 6.13), the ABS_POS register is reset (if ACT = '0') or the ABS_POS register value is copied into the MARK register (if ACT = '1'); then the system performs a SoftStop command. The SPD value is expressed in step/tick (format unsigned fixed point 0.28) that is the same format as the SPEED register (see Section 9.1.4). The SPD value should be lower than MAX_SPEED and greater than MIN_SPEED, otherwise the target speed is imposed at MAX_SPEED or MIN_SPEED respectively. If the SW_MODE bit of the CONFIG register is set low, the external switch turn-on event causes a HardStop interrupt instead of the SoftStop one (see Section 6.13 and 9.1.21). This command keeps the BUSY flag low until the switch turn-on event occurs and the motor is stopped. This command can be given anytime and is immediately executed. 9.2.11 ReleaseSW (ACT, DIR) Table 47. ReleaseSW command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 0 0 1 ACT 0 1 DIR from host The ReleaseSW command produces a motion at minimum speed imposing a forward (DIR = '1') or reverse (DIR = '0') rotation. When SW is released (opened), the ABS_POS register is reset (ACT = '0') or the ABS_POS register value is copied into the MARK register (ACT = '1'); the system then performs a HardStop command. Note that resetting the ABS_POS register is equivalent to setting the HOME position. If the minimum speed value is less than 5 step/s or low speed optimization is enabled, the motion is performed at 5 step/s. The ReleaseSW command keeps the BUSY flag low until the switch input is released and the motor is stopped. Doc ID16737 Rev 4 61/70 Programming manual 9.2.12 L6470 GoHome Table 48. GoHome command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 1 1 0 0 0 0 from host The GoHome command produces a motion to the HOME position (zero position) via the shortest path. Note that this command is equivalent to the “GoTo(0…0)” command. If a motor direction is mandatory, the GoTo_DIR command must be used (see Section 9.2.9). The GoHome command keeps the BUSY flag low until the home position is reached. This command can be given only when the previous motion command has been completed. Any attempt to perform a GoHome command when a previous command is under execution (BUSY low) causes the command to be ignored and the NOTPERF_CMD to rise (see Section 9.1.22). 9.2.13 GoMark Table 49. GoMark command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 1 1 1 1 0 0 0 from host The GoMark command produces a motion to the MARK position performing the minimum path. Note that this command is equivalent to the “GoTo (MARK)” command. If a motor direction is mandatory, the GoTo_DIR command must be used. The GoMark command keeps the BUSY flag low until the MARK position is reached. This command can be given only when the previous motion command has been completed (BUSY flag released). Any attempt to perform a GoMark command when a previous command is under execution (BUSY low) causes the command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22). 9.2.14 ResetPos Table 50. ResetPos command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 1 0 1 1 0 0 0 from host The ResetPos command resets the ABS_POS register to zero. The zero position is also defined as HOME position (see Section 6.5). 62/70 Doc ID16737 Rev 4 L6470 9.2.15 Programming manual ResetDevice Table 51. ResetDevice command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 1 0 0 0 0 0 0 from host The ResetDevice command resets the device to power-up conditions (see Section 6.1). Note: At power-up the power bridges are disabled. 9.2.16 SoftStop Table 52. SoftStop command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 0 1 1 0 0 0 0 from host The SoftStop command causes an immediate deceleration to zero speed and a consequent motor stop; the deceleration value used is the one stored in the DEC register (see Section 9.1.6). When the motor is in high impedance state, a SoftStop command forces the bridges to exit from high impedance state; no motion is performed. This command can be given anytime and is immediately executed. This command keeps the BUSY flag low until the motor is stopped. 9.2.17 HardStop Table 53. HardStop command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 0 1 1 1 0 0 0 from host The HardStop command causes an immediate motor stop with infinite deceleration. When the motor is in high impedance state, a HardStop command forces the bridges to exit from high impedance state; no motion is performed. This command can be given anytime and is immediately executed. This command keeps the BUSY flag low until the motor is stopped. 9.2.18 SoftHiZ Table 54. SoftHiZ command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 0 1 0 0 0 0 0 Doc ID16737 Rev 4 from host 63/70 Programming manual L6470 The SoftHiZ command disables the power bridges (high impedance state) after a deceleration to zero; the deceleration value used is the one stored in the DEC register (see Section 9.1.6). When bridges are disabled, the HiZ flag is raised. When the motor is stopped, a SoftHiZ command forces the bridges to enter into high impedance state. This command can be given anytime and is immediately executed. This command keeps the BUSY flag low until the motor is stopped. 9.2.19 HardHiZ Table 55. HardHiZ command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 0 1 0 1 0 0 0 from host The HardHiZ command immediately disables the power bridges (high impedance state) and raises the HiZ flag. When the motor is stopped, a HardHiZ command forces the bridges to enter into high impedance state. This command can be given anytime and is immediately executed. This command keeps the BUSY flag low until the motor is stopped. 9.2.20 GetStatus Table 56. GetStatus command structure Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 1 1 0 1 0 0 0 0 from host STATUS MSByte to host STATUS LSByte to host The GetStatus command returns the STATUS register value. The GetStatus command resets the STATUS register warning flags. The command forces the system to exit from any error state. The GetStatus command DOES NOT reset the HiZ flag. 64/70 Doc ID16737 Rev 4 L6470 10 Package mechanical data Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Table 57. HTSSOP28 mechanical data mm Dim. Min. Typ. Max. A 1.2 A1 0.15 A2 0.8 b 0.19 0.3 c 0.09 0.2 D (1) 9.6 D1 1.0 9.7 1.05 9.8 5.5 E 6.2 6.4 6.6 E1 (2) 4.3 4.4 4.5 E2 2.8 E 0.65 L 0.45 L1 K 0.6 0.75 1.0 0° Aaa 8° 0.1 1. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs must not exceed 0.15 mm per side. 2. Dimension “E1” does not include interlead flash or protrusions. Interlead flash or protrusions must not exceed 0.25 mm per side. Doc ID16737 Rev 4 65/70 Package mechanical data L6470 Figure 23. HTSSOP28 mechanical data !-V 66/70 Doc ID16737 Rev 4 L6470 Package mechanical data Table 58. POWERSO36 mechanical data mm Dim. Min. Typ. A a1 Max. 3.60 0.10 0.30 a2 3.30 a3 0 0.10 b 0.22 0.38 c 0.23 0.32 D(1) 15.80 16.00 D1 9.40 9.80 E 13.90 14.50 E1(1) 10.90 11.10 E2 E3 2.90 5.8 6.2 e 0.65 e3 11.05 G 0 0.10 H 15.50 15.90 h L 1.10 0.80 N S 1.10 10° 0° Doc ID16737 Rev 4 8° 67/70 Package mechanical data L6470 Figure 24. POWERSO36 drawings 1 1 D H $ '(7$,/$ $ F D '(7$,/% ( H + '(7$,/$ OHDG ' VOXJ D %277209,(: ( % ( ( ' '(7$,/% *DJH3ODQH & 6 K[Û E / 6($7,1*3/$1( * 0 $% 3620(& & &23/$1$5,7< 68/70 Doc ID16737 Rev 4 L6470 11 Revision history Revision history Table 59. Revision history Date Revision 06-Nov-2009 1 Initial release 05-Nov-2010 2 Document status promoted from preliminary data to datasheet 18-May-2011 3 Updated: Table 4, Table 5 Added: Section 6.7.6, Section 6.4.1 4 Added device in POWERSO36 and Figure 3 Updated: Table 2, Table 3, Table 4, Table 5, Table 6, Table 9 and Section 9.1.11. Minor text changes. 19-Jun-2012 Changes Doc ID16737 Rev 4 69/70 L6470 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. 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