ST L6472 User Manual

L6472

dSPIN fully integrated microstepping motor driver with motion engine and SPI

Features

■Operating voltage: 8 - 45 V

■7.0 A output peak current (3.0 A r.m.s.)

■Low RDSon power MOSFETs

■Programmable speed profile

■Programmable Power MOSFET slew rate

■Up to 1/16 microstepping

■Predictive current control with adaptive decay

■Non-dissipative current sensing

■SPI interface

■Low quiescent and standby currents

■Programmable non-dissipative overcurrent protection on all Power MOSFETs

■Two levels of overtemperature protection

Applications

■ Bipolar stepper motor

Description

The L6472, 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 power switches equipped with an accurate on-

chip current sensing circuitry suitable for nondissipative current control and overcurrent protection. Thanks to a new current control, a 1/16 microstepping is achieved through an adaptive decay mode which outperforms traditional implementations. The digital control core can generate user defined motion profiles with acceleration, deceleration, speed or target position, easily programmed through a dedicated register set.

POWERSO36 HTSSOP28

All application commands and data registers, including those used to set analog values (i.e. current control value, current protection trip point, dead time, etc.) are sent through a standard 5- Mbit/s SPI.

A very rich set of protections (thermal, low bus voltage, overcurrent) makes the L6472 “bullet proof”, as required by the most demanding motor control applications.

Table 1.	Device summary
Order codes		Package	Packing
L6472H		HTSSOP28	Tube
L6472HTR		HTSSOP28	Tape and reel
L6472PD		POWERSO36	Tube
L6472PDTR		POWERSO36	Tape and reel

January 2012

Doc ID 022729 Rev 1

1/69

www.st.com

Contents	L6472

Contents

1	Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		. 6
2	Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		. 7
	2.1	Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
	2.2	Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
	2.3	Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
3	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		9
4	Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		14
	4.1	Pin list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
5	Typical applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		17
6	Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		18
	6.1	Device power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
	6.2	Logic I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
	6.3	Charge pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
	6.4	Microstepping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	19

6.4.1 Automatic full-step mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.5	Absolute position counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		20
6.6	Programmable speed profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		20
	6.6.1	Infinite acceleration/deceleration mode . . . . . . . . . . . . . . . . . . . . . . . . .	21
6.7	Motor control commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		21

6.7.1 Constant speed commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6.7.2 Positioning commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6.7.3 Motion commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.7.4 Stop commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.7.5 Step-clock mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.7.6 GoUntil and ReleaseSW commands . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

6.8 Internal oscillator and oscillator driver . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.8.1 Internal oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 6.8.2 External clock source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

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6.9 Overcurrent detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 6.10 Undervoltage lockout (UVLO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.11 Thermal warning and thermal shutdown . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.12 Reset and standby . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.13 External switch (SW pin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.14 Programmable DMOS slew rate, dead time and blanking time . . . . . . . . 28 6.15 Integrated analog-to-digital converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6.16 Internal voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.17 BUSY\SYNC pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

6.17.1 BUSY operation mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.17.2 SYNC operation mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

	6.18	FLAG pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		30
7	Phase current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			31
	7.1	Predictive current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		31
	7.2	Auto-adjusted decay mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		33
	7.3	Auto-adjusted fast decay during the falling steps . . . . . . . . . . . . . . . . . . .		34
	7.4	Torque regulation (output current amplitude regulation) . . . . . . . . . . . . . .		35
8	Serial interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			36
9	Programming manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .			38
	9.1	Register and flag description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		38
		9.1.1	ABS_POS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	39
		9.1.2	EL_POS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	39
		9.1.3	MARK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	40
		9.1.4	SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	40
		9.1.5	ACC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	40
		9.1.6	DEC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	40
		9.1.7	MAX_SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	41
		9.1.8	MIN_SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	41
		9.1.9	FS_SPD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	42
		9.1.10	TVAL_HOLD, TVAL_RUN, TVAL_ACC and TVAL_DEC . . . . . . . . . . . .	42
		9.1.11	T_FAST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	43
		9.1.12	TON_MIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	43
		9.1.13	TOFF_MIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	44

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9.1.14 ADC_OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.1.15 OCD_TH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 9.1.16 STEP_MODE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 9.1.17 ALARM_EN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 9.1.18 CONFIG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 9.1.19 STATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

9.2 Application commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

9.2.1 Command management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 9.2.2 Nop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 9.2.3 SetParam (PARAM, VALUE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 9.2.4 GetParam (PARAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 9.2.5 Run (DIR, SPD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 9.2.6 StepClock (DIR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 9.2.7 Move (DIR, N_STEP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 9.2.8 GoTo (ABS_POS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 9.2.9 GoTo_DIR (DIR, ABS_POS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 9.2.10 GoUntil (ACT, DIR, SPD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 9.2.11 ReleaseSW (ACT, DIR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 9.2.12 GoHome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 9.2.13 GoMark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 9.2.14 ResetPos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 9.2.15 ResetDevice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 9.2.16 SoftStop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 9.2.17 HardStop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 9.2.18 SoftHiZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 9.2.19 HardHiZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 9.2.20 GetStatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

10	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	62
11	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	66

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L6472	List of tables

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 2. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 3. Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 4. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 5. Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 6. Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 7. Typical application values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 8. CL values according to external oscillator frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Table 9. Register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Table 10. EL_POS register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Table 11. MIN_SPEED register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Table 12. Torque regulation by TVAL_HOLD, TVAL_ACC, TVAL_DEC and TVAL_RUN registers . 43 Table 13. Maximum fast decay times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Table 14. Minimum ON time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Table 15. Minimum OFF time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Table 16. ADC_OUT value and torque regulation feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Table 17. Overcurrent detection threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Table 18. STEP_MODE register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Table 19. Step mode selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Table 20. SYNC output frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Table 21. SYNC signal source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Table 22. ALARM_EN register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Table 23. CONFIG register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Table 24. Oscillator management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Table 25. External switch hard stop interrupt mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Table 26. Overcurrent event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Table 27. Programmable power bridge output slew rate values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Table 28. External torque regulation enable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Table 29. Switching period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Table 30. STATUS register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Table 31. STATUS register DIR bit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Table 32. STATUS register MOT_STATE bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Table 33. Application commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 Table 34. NOP command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Table 35. SetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Table 36. GetParam command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Table 37. Run command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Table 38. StepClock command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Table 39. Move command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Table 40. GoTo command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Table 41. GoTo_DIR command structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Table 42. GoUntil command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Table 43. ReleaseSW command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Table 44. GoHome command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Table 45. ResetPos command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Table 46. ResetDevice command structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Table 47. SoftStop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Table 48. HardStop command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

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List of tables	L6472

Table 49. SoftHiZ command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Table 50. HardHiZ command structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Table 51. GetStatus command structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Table 52. HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Table 53. POWERSO36 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Table 54. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

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L6472	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 the L6472 . . . . . . . . . . . . . . . . . . . . . . . . . 19 Figure 5. Charge pump circuitry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Figure 6. Normal mode and microstepping (16 microsteps) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Figure 7. Automatic full-step switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Figure 8. Speed profile in infinite acceleration/deceleration mode . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 9. Constant speed commands examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 10. Positioning command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 11. Motion command examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Figure 12. OSCIN and OSCOUT pin configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Figure 13. External switch connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Figure 14. Internal 3 V linear regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Figure 15. Predictive current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Figure 16. Non-predictive current control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Figure 17. Adaptive decay - fast decay tuning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Figure 18. Adaptive decay - switch from normal to slow+fast decay mode and vice versa . . . . . . . . . 36 Figure 19. Fast decay tuning during the falling steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Figure 20. SPI timings diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Figure 21. Daisy chain configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Figure 22. Command with 3-byte argument. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Figure 23. Command with 3-byte response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Figure 24. Command response aborted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Figure 25. HTSSOP28 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Figure 26. POWERSO36 drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

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Block diagram	L6472

1 Block diagram

Figure 1. Block diagram

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L6472	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
Vout_diff	Differential voltage between VSA,
	OUT1A, OUT2A, PGND and VSB,	VSA = VSB = VS	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
Iout_peak (1)	Pulsed output current	TPULSE < 1 ms	7	A
TOP	Operating junction temperature		150	°C
Ts	Storage temperature range		-55 to 150	°C
Ptot	Total power dissipation (TA = 25 °C)	(2)	5	W

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 EVAL6472H Rev 1.0.

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Electrical data	L6472

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 V	, OUT1 , OUT2 ,
		SB	B	B
	PGND pins
VREG,in	Logic supply voltage				VREG voltage imposed by	3.2	3.3		V
					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 EVAL6472H 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 EVAL6472PD 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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L6472	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					0.7	1	1.3	V
		hysteresis
Iq		Quiescent motor supply		Internal oscillator selected;				0.5	0.65	mA
		current		VREG = 3.3V ext; CP floating
Tj(WRN)		Thermal warning temperature						130		°C
Tj(SD)		Thermal shutdown						160		°C
		temperature
Charge pump
Vpump		Voltage swing for charge						10		V
		pump oscillator
fpump,min		Minimum charge pump						660		kHz
		oscillator frequency (1)
fpump,max		Maximum charge pump						800		kHz
		oscillator frequency (1)
Iboot		Average boot current		fsw,A = fsw,B = 15.6kHz				1.1	1.4	mA
				POW_SR = ‘10’
Output DMOS transistor
		High-side switch on-		Tj = 25°C, Iout = 3A				0.37
		resistance		Tj = 125°C,	(2)	Iout = 3A		0.51
RDS(on)										Ω
		Low-side switch on-		Tj = 25°C, Iout = 3A				0.18
		resistance		Tj = 125°C,	(2)	Iout = 3A		0.23
IDSS		Leakage current		OUT = VS					3.1	mA
				OUT = GND			-0.3
				POW_SR = '00', Iout = +1A				100
				POW_SR = '00', Iout = -1A				80
tr		Rise time (3)		POW_SR = ‘11’, Iout = ±1A				100		ns
				POW_SR = ‘10’, Iout = ±1A				200
				POW_SR = ‘01’, Iout = ±1A				300

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Electrical characteristics								L6472
	Table 5.	Electrical characteristics		(continued)
	Symbol	Parameter		Test condition	Min.	Typ.	Max.		Unit
				POW_SR = '00'; Iout = +1A		90
				POW_SR = '00'; Iout = -1A		110
	tf	Fall time (3)		POW_SR = ‘11’, Iout = ±1A		110			ns
				POW_SR = ‘10’, Iout = ±1A		260
				POW_SR = ‘01’, Iload = ±1A		375
				POW_SR = '00', Iout = +1A		285
				POW_SR = '00', Iout = -1A		360
	SRout_r	Output rising slew rate		POW_SR = ‘11’, Iout = ±1A		285			V/µs
				POW_SR = ‘10’, Iout = ±1A		150
				POW_SR = ‘01’, Iout = ±1A		95
				POW_SR = '00', Iout = +1A		320
				POW_SR = '00', Iout = -1A		260
	SRout_f	Output falling slew rate		POW_SR = ‘11’, Iout = ±1A		260			V/µs
				POW_SR = ‘10’, Iout = ±1A		110
				POW_SR = ‘01’, Iout = ±1A		75
	Dead time and blanking
				POW_SR = '00'		250
				POW_SR = ‘11’,		375
				fOSC = 16MHz
	tDT	Dead time (1)							ns
				POW_SR = ‘10’,		625
				fOSC = 16MHz
				POW_SR = ‘01’,		875
				fOSC = 16MHz
				POW_SR = '00'		250
				POW_SR = ‘11’,		375
				fOSC = 16MHz
	tblank	Blanking time (1)							ns
				POW_SR = ‘10’,		625
				fOSC = 16MHz
				POW_SR = ‘01’,		875
				fOSC = 16MHz
	Source-drain diodes
	VSD,HS	High-side diode forward ON		Iout = 1A		1	1.1		V
		voltage
	VSD,LS	Low-side diode forward ON		Iout = 1A		1	1.1		V
		voltage
	trrHS	High-side diode reverse		Iout = 1A		30			ns
		recovery time

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L6472						Electrical characteristics
	Table 5.	Electrical characteristics		(continued)
	Symbol	Parameter			Test condition		Min.	Typ.	Max.	Unit
	trrLS	Low-side diode reverse		Iout = 1A				100		ns
		recovery time
	Logic inputs and outputs
	VIL	Low logic level input voltage							0.8	V
	VIH	High logic level input voltage					2			V
	IIH	High logic level input current		VIN = 5V					1	µA
		(4)
	IIL	Low logic level input current		VIN = 0V			-1			µA
		(5)
	VOL	Low logic level output voltage		VDD = 3.3V, IOL = 4mA					0.3	V
		(6)
				VDD = 5V, IOL = 4mA					0.3
	VOH	High logic level output voltage		VDD = 3.3V, IOH = 4mA			2.4			V
				VDD = 5V, IOH = 4mA			4.7
	RPU	CS pull-up and STBY pull-			= GND;
				CS			335	430	565	kΩ
	RPD	down resistors		STBY/RST = 5V
	Ilogic	Internal logic supply current		3.3V VREG externally				3.7	4.3	mA
				supplied, internal oscillator
	Ilogic,STBY	Standby mode internal logic		3.3V VREG externally supplied				2	2.5	µA
		supply current
	fSTCK	Step-clock input frequency							2	MHz
	Internal oscillator and external oscillator driver
	fosc,i	Internal oscillator frequency		Tj = 25°C, VREG = 3.3V			-3%	16	+3%	MHz
	fosc,e	Programmable external					8		32	MHz
		oscillator frequency
	VOSCOUT	OSCOUT clock source high		Internal oscillator 3.3V VREG			2.4			V
				externally supplied; IOSCOUT
	H	level voltage
				= 4mA
	VOSCOUTL	OSCOUT clock source low		Internal oscillator 3.3V VREG
		level voltage		externally supplied; IOSCOUT					0.3	V
				= 4mA
	trOSCOUT	OSCOUT clock source rise		Internal oscillator					20	ns
	tfOSCOUT	and fall time
	textosc	Internal to external oscillator						3		ms
		switching delay
	tintosc	External to internal oscillator						1.5		µs
		switching delay
	SPI
	fCK,MAX	Maximum SPI clock					5			MHz
		frequency (7)

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Electrical characteristics								L6472
	Table 5.	Electrical characteristics		(continued)
	Symbol	Parameter		Test condition	Min.	Typ.	Max.		Unit
	trCK	SPI clock rise and fall time (7)		C = 30pF			25		ns
	tfCK			L
	thCK	SPI clock high and low time			75				ns
	tlCK	(7)
	tsetCS	Chip select setup time (7)			350				ns
	tholCS	Chip select hold time (7)			10				ns
	t	De-select time (7)			800				ns
	disCS
	t	Data input setup time (7)			25				ns
	setSDI
	t	Data input hold time (7)			20				ns
	holSDI
	tenSDO	Data output enable time (7)					38		ns
	tdisSDO	Data output disable time (7)					47		ns
	t	Data output valid time (7)					57		ns
	vSDO
	t	Data output hold time (7)			37				ns
	holSDO
	Switch input (SW)
	RPUSW	SW input pull-up resistance		SW = GND	60	85	110		kΩ
	Current control
	ISTEP,max	Max. programmable				4			A
		reference current
	ISTEP,min	Min. programmable reference				31			mA
		current
	Overcurrent protection
		Maximum programmable
	IOCD,MAX	overcurrent detection		OCD_TH = ‘1111’		6			A
		threshold
		Minimum programmable				0.37
	IOCD,MIN	overcurrent detection		OCD_TH = ‘0000’					A
						5
		threshold
	IOCD,RES	Programmable overcurrent				0.37			A
		detection threshold resolution				5
	tOCD,Flag	OCD to flag signal delay time		dIout/dt = 350A/µs		650	1000		ns
	tOCD,SD	OCD to shutdown delay time		dIout/dt = 350A/µs POW_SR =		600			µs
				'10'
	Standby
	IqSTBY	Quiescent motor supply		VS = 8V		26	34		µA
		current in standby conditions		VS = 36V		30	36
	tSTBY,min	Minimum standby time				10			µs
	tlogicwu	Logic power-on and wake-up				38	45		µs
		time

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L6472					Electrical characteristics
	Table 5.	Electrical characteristics		(continued)
	Symbol	Parameter		Test condition		Min.	Typ.	Max.	Unit
	tcpwu	Charge pump power-on and		Power bridges disabled, Cp =			650		µs
		wake-up time		10nF, Cboot = 220nF
	Internal voltage regulator
	VREG	Voltage regulator output				2.9	3	3.2	V
		voltage
	IREG	Voltage regulator output						40	mA
		current
	VREG, drop	Voltage regulator output		IREG = 40mA			50		mV
		voltage drop
	IREG,STBY	Voltage regulator standby						10	mA
		output current
	Integrated analog-to-digital converter
	NADC	Analog-to-digital converter					5		bit
		resolution
	VADC,ref	Analog-to-digital converter					VREG		V
		reference voltage
	fS	Analog-to-digital converter					fOSC/		kHz
		sampling frequency					512

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 the STBY/RST pin which has an internal pull-down resistor.

5.Not valid for the SW and CS pins which have an internal pull-up resistor.

6.FLAG, BUSY and SYNC open drain outputs included.

7.See Figure 20 – SPI timings diagram for details.

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Pin connection	L6472

4 Pin connection

Figure 2. HTSSOP28 pin connection (top view)

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L6472	Pin connection

4.1Pin list

Table 6.		Pin description
No.		Name					Type	Function
17			VDD				Power	Logic output supply voltage (pull-up reference)
6		VREG					Power	Internal 3 V voltage regulator output and 3.3 V external logic
								supply
7		OSCIN					Analog input	Oscillator pin 1. To connect an external oscillator or clock source.
								If this pin is unused, it should be left floating.
								Oscillator pin 2. To connect an external oscillator. When the
8		OSCOUT					Analog output	internal oscillator is used this pin can supply 2/4/8/16 MHz. If this
								pin is unused, it should be left floating.
10			CP				Output	Charge pump oscillator output
11		Vboot					Supply voltage	Bootstrap voltage needed for driving the high-side power DMOS of
								both bridges (A and B)
5		ADCIN					Analog input	Internal analog-to-digital converter input
2			VSA				Power supply	Full bridge A power supply pin. It must be connected to VSB
26
12			VSB				Power supply	Full bridge B power supply pin. It must be connected to VSA
16
27		PGND					Ground	Power ground pin
13
1		OUT1A					Power output	Full bridge A output 1
28		OUT2A					Power output	Full bridge A output 2
14		OUT1B					Power output	Full bridge B output 1
15		OUT2B					Power output	Full bridge B output 2
9		AGND					Ground	Analog ground.
4			SW				Logical input	External switch input pin. If not used the pin should be connected
								to VDD.
21		DGND					Ground	Digital ground
								By default, this BUSY pin is forced low when the device is
22		BUSY\SYNC					Open drain output	performing a command. Otherwise the pin can be configured to
								generate a synchronization signal.
18			SDO				Logic output	Data output pin for serial interface
20			SDI				Logic input	Data input pin for serial interface
19			CK				Logic input	Serial interface clock
23							Logic input	Chip select input pin for serial interface
				CS
								Status flag pin. An internal open drain transistor can pull the pin to
								GND when a programmed alarm condition occurs (step loss,
24		FLAG					Open drain output
								OCD, thermal pre-warning or shutdown, UVLO, wrong command,
								non-performable command)

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Pin connection					L6472
Table 6.		Pin description (continued)
No.		Name		Type	Function
					Standby and reset pin. LOW logic level resets the logic and puts
3		STBY\RST		Logic input	the device into standby mode. If not used, it should be connected
					to VDD
25		STCK		Logic input	Step-clock input
EPAD	Exposed pad			Ground	Internally connected to PGND, AGND and DGND pins

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L6472

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

Figure 4.

Bipolar stepper motor control application using the L6472

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Functional description	L6472

6 Functional description

6.1Device power-up

At the end of power-up, the device state is the following:

●Registers are set to default,

●Internal logic is driven by the 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 IO disabled and power bridges in highimpedance state) until the following conditions are satisfied:

●VS is greater than VSthOn

●VREG is greater than VREGth = 2.8 V (typ.)

●Internal oscillator is operative.

Any motion command causes the device to 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. The VDD pin voltage sets the logic output pin voltage range; when it is connected to VREG or a 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).

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L6472	Functional description

Figure 5. Charge pump circuitry

6.4Microstepping

The driver is able to divide the single step into up to 16 microsteps. Step mode can be programmed by the STEP_SEL parameter in the STEP_MODE register (see Table 19).

Step mode can only be changed when bridges are disabled. Every time 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. Normal mode and microstepping (16 microsteps)

Doc ID 022729 Rev 1

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