ST EVAL6470H-DISC User manual

Introduction
The EVAL6470H-DISC can be used together with the STM32™ firmware library V1.0 and constitutes a complete motor control
evaluation and a development platform.
It is a demonstration board for motor control applications in the range of 8 V to 45 V of DC bus voltage using the STM32F105RB
microcontroller with an internal 128 kB Flash size and a 64 kB internal RAM and the L6470 fully integrated solution suitable for
driving two-phase bipolar stepper motors up to 1/128 microstepping.
The L6470 integrates a dual DMOS full bridge with all of the power switches equipped with an accurate on-chip current sensing
circuitry suitable for non dissipative current control and overcurrent protection.
With dedicated hardware evaluation features, the EVAL6470H-DISC board is designed to help developers evaluate the device
and develop their own applications.
Figure 1. EVAL6470H-DISC board
EVAL6470H-DISC: fully integrated stepper motor driver based on the L6470 and
STM32™
UM1691
User manual
UM1691 - Rev 3 - November 2021
For further information contact your local STMicroelectronics sales office.
www.st.com

1Main features
The characteristics of the EVAL6470H-DISC board are the following:
• DC voltage range from 8 V to 45 V
• Maximum load phase current at 3 Ar.m.s.
• Footprint for external resonator or crystal
• Control interface through trimmer - user keys and switch motor input
• Control through LED indicators
• Interface control by USB and debug outputs
• Compatible with SPINFamily evaluation tool
• Autonomous board due to an embedded firmware
• Up to 1/128 microstepping
• Optimized layout on 2-layer board - low cost and high thermal performance
1.1 Target applications
The demonstration board is designed to fit all typical stepper motor applications - it is an autonomous board due
an embedded firmware.
1.2 Description
The EVAL6470_DISC is downloaded with an embedded firmware.
The possibility with this board is double:
• Adapt the settings with your specific setup (motor - voltage) by using the dedicated PC application.
– The user is able to save inside the board the specific parameters depending on a user setup.
• Using the board (with user parameters) directly on a site - without a connected PC.
UM1691
Main features
UM1691 - Rev 3 page 2/33

2Electrical characteristics of the board
Table 1. Electrical specifications
Name Value
Supply voltage (VS)8 to 45 V
Maximum output current (each phase) 3 A r.m.s
Logic supply voltage (VREG)3 V (L6470 regulator supply)
Logic interface voltage (VDD)3.3 V (USB supply)
Low level logic inputs voltage 0 V
High level logic input voltage VDD
Stepping Up to 1/128 microstepping
Operating temperature 0 to 85 °C
UM1691
Electrical characteristics of the board
UM1691 - Rev 3 page 3/33

3Schematics, layout and bill of material
Figure 2. Schematic (microcontroller supply part)
VDD
USBD M
USBD P
USBD M
5V0
USB_ IT
USBD P
VDD
VDD
C4
100N F
C7
4.7NF
U1
LD1117D33T R
VIN
4NC 5
VOUT 6
GND
1
VOUT
2
VOUT
3VOUT 7
NC 8
J5
1734035- 1
USB_VC C 1
USBDM 2
USBDP 3
USB_ GND 5
SHEL L
6
SHEL L
7
SHEL L
8
ID 4 SHEL L
9
C1
10U F
TP 1
KEYSTONE5000
1
U2
USBLC6 -2 P6
I/O1#1
1
GND
2VBUS 5
I/O2#4 4
I/O1#6 6
I/O2#3
3
R5
1.5K
R4
1M
C3
100N F
Figure 3. Schematic (microcontroller part)
SW MOTOR LEFT RI GHTRESET
BOOT
SPARE BUSYERROR READY
START/STOP
STCK
GND GND
STBY_RESET
BOARD_ID_0
SPI_NSS SPI_NCK
BOARD_ID_1
SPI_MISO
BOARD_ID_2
SPI_MOSI
BOARD_ID_3
PA8_UART1_CK
PA9_UART1_TX
PA10_UART1_RX
USBDM
USBDP
PA13_TMS
BOOT1
RESET
SW
RESET
JTAG_NTSRT JTAG_TDO
JTAG_TCK JTAG_TDI
BOOT0
SW _MOTOR
BUTTON_A
BUTTON_B
USB_IT
FLAG BUSY
LED_READY
LED_BUSY
LED_ERROR
LED_SPARE
VDD
VDD
VDDVDD
VDD
VDD VDD
VDD
VDD
VDD
VDD
VDD
VDD
R10
10K
R31
10K
C19
100NF
R12
100R
C2
1UF
R28
100K
R20
1K
C25
100NF
R17
470R
TP5
1
C20
10NF
R19
10K
TP6
1
R21
NP
C26
100NF
D5
YELLOW
R25
4.7K
R6
10K
D3
RED
R13
1M
U4
STM32F105RBT6
PD2 54
PC12 53 PC11 52 PC10 51
PA15 50 PA14 49
VDD_2 48
VSS_2 47
PA13 46
PA12 45
PA11 44
PA10 43
PA9 42
PA8 41
PC9 40
PC8 39
PC7 38
PC6 37
VBAT
1
PC13-TAMPER-RTC
2
PC14-OSC32_IN
3
PC15-OSC32_OUT
4
PD0 OSC_IN
5
PD1 OSC_OUT
6
PC0
8NRST
7
VSSA
12
PC1
9
VDD-4
19
PC2
10
PC3
11
VDDA
13
PA0-WKUP
14
PA1
15
PA2
16
PA3
17
VSS_4
18
PA4
20
PA5
21
PA6
22
PA7
23
PC4
24
PC5
25
PB0
26
PB1
27
PB2
28
PB6 58
PB15 36
PB14 35
PB13 34
PB12 33
VSS_1
31 PB11 30
VDD_1
32
PB10
29
PB5 57 PB4 56 PB3 55
BOOT0 60
PB7 59 PB8 61 PB9 62
VSS_3 63
VDD_3 64
R24
4.7K
D4
GREEN
C18
100NF
C23
20PF
D6
ORANGE
R26
4.7K
R22
NP
J6
OPEN
22-28-4023
C24
20PF
C16
10UF
C22
100NF
C28
10NF
R27
4.7K
R18
470R
S1
1 3
42
R16
470R
S3
1 3
42
C21
100NF
J4
CON-FLAT-10X2-180M
1
3
5
7
9
11
13
15
17
19
2
4
6
8
10
12
14
16
18
20
R15
470R
R14
10K
R23
NP
R7
100R
J7
OPEN
R11
10K
R8
10K
C27
100NF
R33
1K
C15
10NF
R32
10K
Y1
8MHz
R9
10K
C17
100NF
R30
10K
S2
1 3
42
TP4
1
UM1691
Schematics, layout and bill of material
UM1691 - Rev 3 page 4/33

Figure 4. Schematic (motor driver part)
A1
A2
B1
B2
OSCIN
OSCOUT
VS GND
XTAL
ADCIN
BUSY
SPI_MOSI
SPI_NCK
SPI_NSS
SW
SPI_MISO
STBY_RESET
STCK
ADCIN
FLAG
VS
VS
VDD
VS
C5
3.3NF
C10
100NF
J3
1
2
TP2
1
TP3
1
D1
3.6V
TP7
KEYSTONE5000
1
D2 BAV9 9
2 1
3
C12
100NF
R29
NP
R2
27K
R34
NP
C8
10NF
J1
1
2
+
C14
100UF
63V
R1
200K
13
2
R3
7.5K
C13
100NF
C11
100NF
J2
1
2
U3
L6470H
VDD 17
VREG 6
OSCIN
7
OSCOUT
8
CP 10
VBOOT 11
ADCIN
5
VSA 2 VSA 26 VSB 12 VSB 16
PGND
13
PGND
27
OUT1A 1
OUT2A 28
OUT1B 14
OUT2B 15
AGND
9
SW
4
DGND
21
BUSY_SYNC
22 FLAG
24
SDO
18 SDI
20 CK
19 CS
23
STBY_RES
3STCK
25
EPAD
29
+
C9
47UF
C6
220NF
Figure 5. Layout top layer and bottom layer
UM1691
Schematics, layout and bill of material
UM1691 - Rev 3 page 5/33

Table 2. Bill of material
Item Quantity Reference Value Package
C1, C16 2 Cap. cer. 10 µF 10 V X7R 10 µF 0805
C2 1 Cap. cer. 1 µF 10 V X7R 1 µF 0805
C3, C4, C10,
C13, C17, C19,
C21, C22, C25,
C27
14 Cap. cer. 100 nF 50 V X7R 100 nF 0603
C5 1 Cap. cer. 3.3 nF 50 V X7R 3.3 nF 0603
C6 1 Cap. cer. 220 nF 35 V X7R 220 nF 0603
C7 1 Cap. cer. 4.7 nF 50V X7R 4.7 nF 0603
C8, C15, C20,
C28 4 Cap. cer. 10 nF 50 V X7R 10 nF 0603
C9 1 Cap. tant. 47 µF 6.3 V 10% 47 µF 3216
C14 1 Cap. elec. 100 µF 63 V 100 µF CAPES-R10HXX
C23, C24 2 Cap. Cer. 20 pF 50 V COG 20 pF 0603
D1 1 Zener regulator 3.6 V SOD 523
D2 1 Double diode - high speed switching diode BAV99 SOT23
D3 1 LED red - 2 mcd - 621 nm Red 0805
D4 1 LED green - 6 mcd - 569 nm Green 0805
D5 1 LED yellow - 6 mcd - 588 nm Yellow 0805
D6 1 LED orange - 2 mcd - 602 nm Orange 0805
FIX1, FIX4 4 Hole 3 mm -
J1, J3 3 Screw connector 2 poles MKDSN 1.5/2 - 5.08 MKDSN 1.5/2 - 5.08
J4 1 JTAG connector CON-FLAT-10 x2 - 180 M CON-FLAT-10 x2 -180
M
J5 1 USB_B_MINI_AMP_1734035-1 CN-USB CMS Mini USB
J6, J7 2 Jumper OPEN STRIP 2x 2.54
R1 1 Trimmer 200 kΩ 200 kΩ Trimm. 100 x 50 x 110
R2 1 27 kΩ 5% 1/10 W 27 kΩ 0603
R3 1 Res. 7.5 kΩ 5% 1/10 W 7.5 kΩ 0603
R4, R13 2 Res. 1 MΩ 1/10 W 5% 1 MΩ 0603
R5 1 Res. 1.5 kΩ 1/10 W 5% 1.5 kΩ 0603
R6, R8, R11,
R14, R19, R30,
R32
10 Res. 10 kΩ 5% 1/10 W 10 kΩ 0603
R7, R12 2 Res. 100 Ω 5% 1/10 W 100 Ω 0603
R15, R18 4 Res. 470 Ω 5% 1/10 W 0603 470 Ω 0603
R20, R33 2 Res. 1 kΩ 5% 1/10 W 1 kΩ 0603
R21, R23, R34 4 Resistor N.M. 0603
R24, R27 4 Res. 4.7 kΩ 5% 1/10 W 4.7 kΩ 0603
R28 1 Res. 100 kΩ 5% 1/10 W 100 kΩ 0603
R29 1 Resistor N.M. 0805
S1, S3 3 Switch button SMD EVQQ2D03W CMS 6.5 x 6 x 3.1
UM1691
Schematics, layout and bill of material
UM1691 - Rev 3 page 6/33

Item Quantity Reference Value Package
TP1, TP2, TP4,
TP7 6 Test point red KEYSTONE-5000 TH
TP3 1 Test point black KEYSTONE-5001 TH
U1 1 REG 1300mA LN 3.3 V LD1117D33TR SO8
U2 1 USBLC6-2P6 USBLC6-2P6 SOT 666
U3 1 L6470 microstepping motor driver L6470 HTSSOP28
U4 1 MCU, RISC, 72MHz, 3.6 V,
32-bit, 64-pin, LQFP STM32F105RBT6 LQFP64 10 x 10
Y1 1 XTAL 8 MHz-30 PPM-20 pF 8 MHz HC49/US-SM
UM1691
Schematics, layout and bill of material
UM1691 - Rev 3 page 7/33

4General description
4.1 Power supply
The EVAL6470H-DISC board is designed to be powered via:
• Connector J1: power of the motor and also motor control driver.
• USB connector J5: power of the microcontroller and logic control.
The USB cable supplies the digital part through a dedicated LDO (U1) providing 3.3 V.
The motor power must be set according to the voltage required by the user motor.
Note: Both the supply sources (USB connector and J1 connector) must be present to make the board
operative.
Figure 6. Microcontroller supply section
VDD
USBD M
USBD P
USBD M
5V0
USB_ IT
USBD P
VDD
VDD
C4
100N F
C7
4.7NF
U1
LD1117D33T R
VIN
4NC 5
VOUT 6
GND
1
VOUT
2
VOUT
3VOUT 7
NC 8
J5
1734035- 1
USB_VC C 1
USBDM 2
USBDP 3
USB_ GND 5
SHELL
6
SHELL
7
SHELL
8
ID 4 SHELL
9
C1
10U F
TP 1
KEYSTONE5000
1
U2
USBLC6 -2P6
I/O1#1
1
GND
2VBUS 5
I/O2#4 4
I/O1#6 6
I/O2#3
3
R5
1.5K
R4
1M
C3
100N F
UM1691
General description
UM1691 - Rev 3 page 8/33

4.2 L6470 stepper motor driver
The L6470 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.
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
• Two levels of overtemperature protection
Figure 7. L6470 block diagram
3 V
Voltage Reg.
ADC
Ext. Osc. driver
&
Clock gen.
16MHz
Oscillator
Charge
pump
VDD
SPI Registers
Control
Logic
Current DACs
&
Comparators
Temperature
sensing
Current
sensing
STBY
FLAG
CS
CK
SDO
SDI
BUSY
SW
STCK
DGND
VDD OSCIN OSCOUT ADCIN VREG CP VBOOT
AGND
PGND
PGND
VSA
VSA
OUT1A
OUT2A
VSB
VSB
OUT1B
OUT2B
HS A1
LS A1
HS A2
LS A2
HS B1
LS B1
HS B2
LS B2
HS A1
LS A1
HS A2
LS A2
HS B1
LS B1
HS B2
LS B2
VDD
Vboot
Vboot Vboot
Vboot
Table 3. L6470 recommended operating conditions
Symbol Parameter Test condition Value Unit
VDD Logic Interface supply voltage 3.3 V
VSMotor supply voltage VSA = VSB = VS8 ÷ 45 V
VOUT_diff Differential between voltage VSA, OUTI1A, OUT2A,PGND and VSB, OUT1B,
OUT2B, PGND pins VSA = VSB =VSUp to 45 V
VREG in Logic supply voltage VREG internal 3 V
VADC Integrated ADC input voltage range (ADCIN pin) 0 ÷ VREG V
UM1691
L6470 stepper motor driver
UM1691 - Rev 3 page 9/33

4.2.1 Charge pump
The L6470 device uses an internal charge pump for driving correctly the integrated MOSFETs, a voltage higher
than the motor power supply. The charge pump is obtained through an oscillator and few external components.
Figure 8. Charge pump circuitry
VS
D2 BAV9 9
2 1
3
C8
10 n F
U3 L6470H
CP
10
VBOOT
11
VSA
2
VSA
26
VSB
12
VSB
16
C6
220 nF
4.2.2 Voltage mode driving
The configuration parameters of the voltage mode driving can be obtained through the BEMF compensation tool
embedded into the SPINFamily software.
A wrong setup of these parameters could cause several issues, in particular:
• The phase current decreases with the speed and the motor will stall.
• The wrong voltage is applied to the motor and the system is very noisy.
• The phase current reaches the overcurrent limit.
The BEMF compensation form uses the application parameters as inputs in order to evaluate the proper device
setup.
The required inputs are:
• Supply voltage.
• Target phase current (r.m.s. value) at different motion conditions (acceleration, deceleration, constant speed
and holding).
• Target operating speed (maximum speed).
• Motor characteristics.
The motor characteristics are: electrical constant (Ke), phase inductance and resistance.
The inductance and the resistance of the phase are given in the motor datasheet. The Ke is rarely given in the
specification and must be measured.
In the help section of the SPINFamily software a step by step procedure is explained. The same procedure can
also be found in the application note “AN4144: Voltage mode control operation and parameter optimization” on .
Click on the “evaluate” button to get the suggested setup for the voltage mode driving. Then click on “write” button
to copy the data in the registers of the device.
UM1691
L6470 stepper motor driver
UM1691 - Rev 3 page 10/33