ST L6470 User Manual

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

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. Device summary

POWERSO36 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 5- Mbit/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.

Order codes	Package	Packaging
L6470H	HTSSOP28	Tube
L6470HTR	HTSSOP28	Tape and reel
L6470PD	POWERSO36	Tube
L6470PDTR	POWERSO36	Tape and reel

June 2012

Doc ID16737 Rev 4

1/70

This is information on a product in full production.

www.st.com

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 Automatic full-step mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

6.5	Absolute position counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		23
6.6	Programmable speed profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		23
	6.6.1	Infinite acceleration/deceleration mode . . . . . . . . . . . . . . . . . . . . . . . . .	24

6.7 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

6.8 Internal oscillator and oscillator driver . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

6.8.1 Internal oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.8.2 External clock source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

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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

6.17.1 BUSY operation mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 6.17.2 SYNC operation mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

6.18 FLAG pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

7	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

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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

9.2 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

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L6470	List of tables

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 2. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 3. Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 4. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 5. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Table 6. Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 7. Typical application values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 8. CL values according to external oscillator frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table 9. Registers map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Table 10. EL_POS register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Table 11. MIN_SPEED register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Table 12. Voltage amplitude regulation registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Table 13. Winding resistance thermal drift compensation coefficient . . . . . . . . . . . . . . . . . . . . . . . . . 45 Table 14. ADC_OUT value and motor supply voltage compensation feature . . . . . . . . . . . . . . . . . . 46 Table 15. Overcurrent detection threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Table 16. Stall detection threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Table 17. STEP_MODE register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Table 18. Step mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Table 19. SYNC output frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Table 20. SYNC signal source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Table 21. ALARM_EN register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Table 22. CONFIG register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Table 23. Oscillator management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Table 24. External switch hard stop interrupt mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Table 25. Overcurrent event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Table 26. Programmable power bridge output slew rate values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Table 27. Motor supply voltage compensation enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Table 28. PWM frequency: integer division factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Table 29. PWM frequency: multiplication factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Table 30. Available PWM frequencies [kHz]: 8-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . . 52 Table 31. Available PWM frequencies [kHz]: 16-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . 52 Table 32. Available PWM frequencies [kHz]: 24-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . 53 Table 33. Available PWM frequencies [kHz]: 32-MHz oscillator frequency . . . . . . . . . . . . . . . . . . . . 53 Table 34. STATUS register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Table 35. STATUS register DIR bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Table 36. STATUS register MOT_STATE bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Table 37. Application commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Table 38. Nop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Table 39. SetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Table 40. GetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Table 41. Run command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Table 42. Stepclock command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Table 43. Move command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Table 44. GoTo command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Table 45. GoTo_DIR command structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Table 46. GoUntil command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Table 47. ReleaseSW command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Table 48. GoHome command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

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List of tables	L6470

Table 49. GoMark command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Table 50. ResetPos command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Table 51. ResetDevice command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Table 52. SoftStop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Table 53. HardStop command structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Table 54. SoftHiZ command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Table 55. HardHiZ command structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Table 56. GetStatus command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Table 57. HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Table 58. POWERSO36 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Table 59. Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

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L6470	List of figures

List of figures

Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Figure 2. HTSSOP28 pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 3. POWERSO36 pin connection (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Figure 4. Bipolar stepper motor control application using L6470 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Figure 5. Charge pump circuitry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 6. Normal mode and microstepping (128 microsteps) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 7. Automatic full-step switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 8. Speed profile in infinite acceleration/deceleration mode . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 9. Constant speed command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Figure 10. Positioning command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Figure 11. Motion command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 12. OSCIN and OSCOUT pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Figure 13. External switch connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Figure 14. Internal 3 V linear regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Figure 15. Current distortion and compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Figure 16. BEMF compensation curve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Figure 17. Motor supply voltage compensation circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Figure 18. SPI timings diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Figure 19. Daisy chain configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Figure 20. Command with 3-byte argument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Figure 21. Command with 3-byte response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Figure 22. Command response aborted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Figure 23. HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Figure 24. POWERSO36 drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

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Block diagram	L6470

1 Block diagram

Figure 1. Block diagram

	VDD	OSCIN	OSCOUT ADCIN	VREG	CP	VBOOT
		Ext. Osc. driver			Charge
	16MHz				pump
			&
	Oscillator						VSA
		Clock gen.		3 V
STBY/RST			ADC	Voltage Reg.	Vboot	Vboot	VSA
FLAG					HS A1		HS A2
							OUT1A
	sters			HS A1			OUT2A
				LS A1
				HS A2	LS A1		LS A2
	Regi
			Control	LS A2			PGND
	VDD
			Logic
				HS B1			VSB
CS				LS B1	Vboot	Vboot	VSB
CK				HS B2
	SPI			LS B2	HS B1		HS B2
SDO
							OUT1B
SDI							OUT2B
BUSY/SYNC			Temperature	Current DACs	LS B1		LS B2
				&
			sensing
				Comparators
							PGND
STCK
	VDD
						Current
SW						sensing
	DGND						AGND
							AM02377v1

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L6470	Electrical data

2 Electrical data

2.1Absolute maximum ratings

Table 2.		Absolute maximum ratings
Symbol		Parameter	Test condition	Value	Unit
VDD		Logic interface supply voltage		5.5	V
VS		Motor supply voltage	VSA = VSB = VS	48	V
VGND, diff		Differential voltage between AGND,		±0.3	V
		PGND and DGND
Vboot		Bootstrap peak voltage		55	V
VREG		Internal voltage regulator output pin		3.6	V
		and logic supply voltage
VADCIN		Integrated ADC input voltage range		-0.3 to +3.6	V
		(ADCIN pin)
VOSC		OSCIN and OSCOUT pin voltage		-0.3 to +3.6	V
		range
		Differential voltage between VSA,	VSA = VSB = VS
Vout_diff		OUT1A, OUT2A, PGND and VSB,		48	V
		OUT1B, OUT2B, PGND pins
VLOGIC		Logic inputs voltage range		-0.3 to +5.5	V
	(1)	R.m.s. output current		3	A
Iout
	(1)	Pulsed output current	TPULSE < 1 ms	7	A
Iout_peak
TOP		Operating junction temperature		150	°C
Ts		Storage temperature range		-55 to 150	°C
P	tot	Total power dissipation (T = 25 ºC)	(2)	5	W
		A

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.

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Electrical data	L6470

2.2Recommended operating conditions

Table 3.	Recommended operating conditions
Symbol	Parameter	Test condition		Value		Unit
VDD	Logic interface supply voltage	3.3 V logic outputs		3.3		V
		5 V logic outputs		5
VS	Motor supply voltage	VSA = VSB = VS	8		45	V
	Differential voltage between
Vout_diff	VSA, OUT1A, OUT2A, PGND	VSA = VSB = VS			45	V
	and VSB, OUT1B, OUT2B,
	PGND pins
VREG,in	Logic supply voltage	VREG voltage imposed	3.2	3.3		V
		by external source
VADC	Integrated ADC input voltage		0		VREG	V
	(ADCIN pin)
Tj	Operating junction temperature		- 25		125	°C

2.3Thermal data

	Table 4.	Thermal data
	Symbol	Parameter	Package		Typ.	Unit
	RthJA	Thermal resistance junction-ambient	HTSSOP28	(1)	22	°C/W
			POWERSO36 (2)		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.

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L6470	Electrical characteristics

3 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
		Internal oscillator selected;
Iq	Quiescent motor supply current	VREG = 3.3 V ext; CP						0.5	0.65	mA
		floating
Tj(WRN)	Thermal warning temperature							130		°C
Tj(SD)	Thermal shutdown temperature							160		°C
Charge pump
Vpump	Voltage swing for charge pump oscillator							10		V
fpump,min	Minimum charge pump oscillator frequency							660		kHz
	(1)
fpump,max	Maximum charge pump oscillator frequency							800		kHz
	(1)
Iboot	Average boot current	fsw,A = fsw,B = 15.6 kHz						1.1	1.4	mA
		POW_SR = '10'
Output DMOS transistor
RDS(on)	High-side switch on-resistance	Tj = 25 °C, Iout = 3 A						0.37
		T	= 125 °C, (2)	I		= 3 A		0.51
		j		out						Ω
RDS(on)	Low-side switch on-resistance	Tj = 25 °C, Iout = 3 A						0.18
		Tj = 125 °C, (2) Iout = 3 A						0.23
IDSS	Leakage current	OUT = VS							3.1	mA
		OUT = GND					-0.3
		POW_SR = '00', Iout = +1 A						100
		POW_SR = '00', Iout = -1 A						80
t	Rise time (3)	POW_SR = '11', I				= ±1 A		100		ns
r					out
		POW_SR = '10', Ilout = ±1 A						200
		POW_SR = '01', Iout = ±1 A						300

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Electrical characteristics							L6470
Table 5.		Electrical characteristics (continued)
Symbol		Parameter	Test condition	Min.	Typ.	Max.		Unit
			POW_SR = '00'; Iout = +1 A		90
			POW_SR = '00'; Iout = -1 A		110
t	f	Fall time (3)	POW_SR = '11', I = ±1 A		110			ns
			out
			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
SRout_r		Output rising slew rate	POW_SR = '11', Iout = ±1 A		285			V/µs
			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
SRout_f		Output falling slew rate	POW_SR = '11', Iout = ±1 A		260			V/µs
			POW_SR = '10', Iout = ±1 A		110
			POW_SR = '01', Iout = ±1 A		75
Deadtime and blanking
			POW_SR = '00'		250
			POW_SR = '11',		375
			fOSC = 16 MHz
t		Deadtime (1)	POW_SR = '10',					ns
DT					625
			fOSC = 16 MHz
			POW_SR = '01',		875
			fOSC = 16 MHz
			POW_SR = '00'		250
			POW_SR = '11',		375
			fOSC = 16 MHz
t		Blanking time (1)	POW_SR = '10',					ns
blank					625
			fOSC = 16 MHz
			POW_SR = '01',		875
			fOSC = 16 MHz
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

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L6470

Electrical characteristics

Table 5.

Electrical characteristics (continued)

Symbol

Parameter

Test condition

Min.

Typ.

Max.

Unit

Logic inputs and outputs

VIL

Low logic level input voltage

0.8

V

VIH

High logic level input voltage

2

V

I

High logic level input current (4)

V

IN

= 5 V

1

µA

IH

I

Low logic level input current (5)

V

IN

= 0 V

-1

µA

IL

V

Low logic level output voltage (6)

VDD = 3.3 V, IOL = 4 mA

0.3

V

OL

VDD = 5 V, IOL = 4 mA

0.3

VDD = 3.3 V, IOH = 4 mA

2.4

VOH

High logic level output voltage

VDD = 5 V,

4.7

V

IOH = 4 mA

RPU

= GND;

CS pull-up and STBY pull-down resistors

CS

335

430

565

kΩ

RPD

STBY/RST = 5 V

Ilogic

Internal logic supply current

3.3 V VREG externally

3.7

4.3

mA

supplied, internal oscillator

Ilogic,STBY

Standby mode internal logic supply current

3.3 V VREG externally

2

2.5

µA

supplied

fSTCK

Step-clock input frequency

2

MHz

Internal oscillator and external oscillator driver

fosc,i

Internal oscillator frequency

Tj = 25 °C,

-3%

16

+3%

MHz

VREG = 3.3 V

fosc,e

Programmable external oscillator frequency

8

32

MHz

Internal oscillator 3.3 V

VOSCOUTH

OSCOUT clock source high level voltage

VREG externally supplied;

2.4

V

IOSCOUT = 4 mA

Internal oscillator 3.3 V

VOSCOUTL

OSCOUT clock source low level voltage

VREG externally supplied;

0.3

V

IOSCOUT = 4 mA

trOSCOUT

OSCOUT clock source rise and fall time

Internal oscillator

20

ns

tfOSCOUT

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

SPI clock rise and fall time (7)

C

L

= 30 pF

25

ns

tfCK

thCK

SPI clock high and low time

(7)

75

ns

tlCK

tsetCS

Chip select setup time (7)

350

ns

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Electrical characteristics						L6470
Table 5.	Electrical characteristics (continued)
Symbol	Parameter	Test condition	Min.	Typ.	Max.		Unit
tholCS	Chip select hold time (7)		10				ns
tdisCS	Deselect time (7)		800				ns
tsetSDI	Data input setup time (7)		25				ns
tholSDI	Data input hold time (7)		20				ns
tenSDO	Data output enable time (7)				38		ns
tdisSDO	Data output disable time (7)				47		ns
tvSDO	Data output valid time (7)				57		ns
tholSDO	Data output hold time (7)		37				ns
Switch input (SW)
RPUSW	SW input pull-up resistance	SW = GND	60	85	110		kΩ
PWM modulators
fPWM	Programmable PWM frequency (1)	fosc = 16 MHz	2.8		62.5		kHz
		fosc = 32 MHz	5.6		125
NPWM	PWM resolution			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			mA
				5
ISTALL,RES	Programmable stall threshold resolution			31.2			mA
				5
Overcurrent protection
IOCD,MAX	Maximum programmable overcurrent	OCD_TH = '1111'		6			A
	detection threshold
IOCD,MIN	Minimum programmable overcurrent	OCD_TH = '0000'		0.37			A
	detection threshold			5
IOCD,RES	Programmable overcurrent detection			0.37			A
	threshold resolution			5
tOCD,Flag	OCD to flag signal delay time	dIout/dt = 350 A/µs		650	1000		ns
tOCD,SD	OCD to shutdown delay time	dIout/dt = 350 A/µs		600			ns
		POW_SR = '10'
Standby
IqSTBY	Quiescent motor supply current in standby	VS = 8 V		26	34		µA
	conditions	VS = 36 V		30	36
tSTBY,min	Minimum standby time			10			µs
tlogicwu	Logic power-on and wake-up time			38	45		µs

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L6470			Electrical characteristics
Table 5.	Electrical characteristics (continued)
Symbol	Parameter	Test condition		Min.	Typ.	Max.	Unit
tcpwu	Charge pump power-on and wake-up time	Power bridges disabled,			650		s
		Cp = 10 nF, Cboot = 220 nF
Internal voltage regulator
VREG	Voltage regulator output voltage			2.9	3	3.2	V
IREG	Voltage regulator output current					40	mA
VREG, drop	Voltage regulator output voltage drop	IREG = 40 mA			50		mV
IREG,STBY	Voltage regulator standby output current					10	mA
Integrated analog-to-digital converter
NADC	Analog-to-digital converter resolution				5		bit
VADC,ref	Analog-to-digital converter reference voltage				VRE		V
					G
fS	Analog-to-digital converter sampling				fPWM		kHz
	frequency

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.

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Pin connection	L6470

4 Pin connection

Figure 2. HTSSOP28 pin connection (top view)

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63!			0'.$
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#0			#+
6"//4			3$/
63"			6$$
0'.$			63"
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!-V

Figure 3. POWERSO36 pin connection (top view)

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Doc ID16737 Rev 4

L6470	Pin connection

4.1Pin 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
									Oscillator pin 1. To connect an external oscillator or
	7	10		OSCIN				Analog input	clock source. If this pin is unused, it should be left
									floating.
									Oscillator pin 2. To connect an external oscillator.
	8	11		OSCOUT				Analog output	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.
	10	13			CP			Output	Charge pump oscillator output
	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
	22	29	BUSY\SYNC					Open drain output
									can be configured to generate a synchronization
									signal.
	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						Logic input	Chip select input pin for serial interface
					CS

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Pin connection								L6470
Table 6.	Pin description (continued)
	No.		Name				Type	Function
HTSSOP	POWERSO
								Status flag pin. An internal open drain transistor can
								pull the pin to GND when a programmed alarm
24	31			FLAG			Open drain output	condition occurs (step loss, OCD, thermal pre-
								warning or shutdown, UVLO, wrong command, non-
								performable command)
								Standby and reset pin. LOW logic level resets the
3	6		STBY\RST				Logic input	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	Exposed pad					Ground	Internally connected to PGND, AGND and DGND pins

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Doc ID16737 Rev 4

L6470			Typical applications
5	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)

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Typical applications	L6470

Figure 4. Bipolar stepper motor control application using L6470

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Doc ID16737 Rev 4

L6470	Functional description

6 Functional description

6.1Device 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).

6.2Logic 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.

6.3Charge 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

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