LV8712T/LV8713T Application Note

LV8712T/LV8713T
Bi-CMOS LSI
PWM Constant-Current Control
Stepper Motor Driver
Application Note
http://onsemi.com
Overview
The LV8712T and LV8713T are micro-stepping motor drivers with built-in translator for easy operation.
The LV8712T supports full-step, half-step, quarter-step, and 1/8-step resolution. The LV8713T supports
full-step, half-step, 1/16-step, and 1/32-step resolution. These ICs are optimal for driving stepping motor of
scanner and small printer.
Function
 Single-channel PWM constant-current control stepping motor driver incorporated.
 Microstepping is configurable to the following modes:
Full-step, half-step, quarter-step, or 1/8-step. (LV8712T)
Full-step, half-step, 1/16-step, or 1/32-step. (LV8713T)
 CLK-IN input facilitates the control of microstepping.
 Power-supply voltage of motor
: VM max = 18V
 Output current
: IO max = 0.8A
 Output ON resistance
: RON = 1.1Ω (upper and lower total, typical, Ta = 25C)
 Thermal shutdown circuit and low voltage detecting circuit incorporated.
Typical Applications
 POS Printer
 Scanner
 Thermal Printer Unit
 Security camera
 Air-conditioner
Selection Guide
Part Number
LV8712T
LV8713T
Microstepping mode
Full-,half-,quarter-,1/8-step
Full-,half-,1/16-,1/32-step
Semiconductor Components Industries, LLC, 2013
December, 2013
1/35
LV8712T/LV8713T Application Note
RNF2
OUT2B
PGND
MD1
MD2
ATT1
ATT2
CHOP
VCC
GND
OUT2A
STEP
VREF
VM
OUT1B
RNF1
PS
MONI
PGND
REG5
OE
RST
FR
OUT1A
Pin Assignment
Package Dimension
unit: mm (typ)
3260A
6.5
0.5
6.4
13
4.4
24
12
1
0.5
0.15
0.22
0.08
1.2max
(1.0)
(0.5)
SANYO : TSSOP24(225mil)
Caution: The package dimension is a reference
value, which is not a guaranteed value.
Recommended Soldering Footprint
(Unit:mm)
Reference symbol
TSSOP24 (225mil)
eE
5.80
e
0.50
b3
0.32
l1
1.00
2/35
GND
VREF
VCC
REG5
LVS
TSD
PS
Attenuator
(100%/80%/
60%/40%)
CHOP ATT1 ATT2
Oscillation
circuit
1/5
Start circuit
Standard
voltage
VM-5V
Standard
voltage
RNF1
OUT2A
Output control logic
VM
Microstep
mode
selection
OUT2B RNF2
MD1 MD2 FR STEP RST OE
OUT1B
Microstep
mode
selection
OUT1A
MONI
PGND
LV8712T/LV8713T Application Note
Block Diagram
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LV8712T/LV8713T Application Note
Specifications
Absolute Maximum Ratings at Ta = 25C
Parameter
Symbol
Motor supply voltage
VM max
Logic supply voltage
VCC max
Conditions
Ratings
Unit
18
V
6
V
Output peak current
IO peak
Each 1ch, tw  10ms, duty 20%
1.0
A
Output continuousness current
IO max
Each 1ch
800
mA
Logic input voltage
VIN
Allowable power dissipation
Pd max
1.35
W
Operating temperature
Topr
-20 to +85
C
Storage temperature
Tstg
-55 to +150
C
-0.3 to VCC + 0.3
*
V
* Specified circuit board: 57.0mm57.0mm1.7mm, glass epoxy 2-layer board
Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time.
Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage
under high temperature, high current, high voltage, or drastic temperature change, the reliability of the IC may be
degraded. Please contact us for the further details.
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating
Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
Recommended Operating Conditions at Ta  25C
Parameter
Motor supply voltage range
Symbol
Conditions
Ratings
min
typ
VM
Unit
max
4
16
V
V
Logic supply voltage range
VCC
2.7
5.5
Logic input voltage
VIN
-0.3
VCC+0.3
V
VREF input voltage range
VREF
0
VCC-1.8
V
Electrical Characteristics at Ta = 25°C, VM = 12V, VCC = 3.3V, VREF = 1.0V
Parameter
Standby mode current drain
Operating mode current drain
Symbol
Conditions
Ratings
min
typ
Unit
max
IMstn
PS = “L”, no load
1
A
ICCstn
PS = “L”, no load
1
A
IM
PS = “H”, no load
0.3
0.5
0.7
mA
ICC
PS = “H”, no load
0.9
1.3
1.7
mA
Thermal shutdown temperature
TSD
Design guarantee
180
Thermal hysteresis width
TSD
Design guarantee
40
VCC low voltage cutting voltage
Low voltage hysteresis voltage
VthVCC
VthHIS
REG5 output voltage
Vreg5
IO = -1mA
RonU
RonD
IO = -800mA, Source-side on resistance
IO = 800mA, Sink-side on resistance
Diode forward voltage
IOleak
VD
VO = 15V
ID = -800mA
Logic pin input current
IINL
Logic high-level input voltage
Logic low-level input voltage
IINH
VINH
VINL
VIN = 0.8V
VIN = 3.3V
VREF input current
IREF
Output on resistance
Output leakage current
C
C
2.1
2.4
2.7
V
100
130
160
mV
4.5
5
5.5
V
0.78
1.0

0.32
0.43

10
A
1.0
1.2
V
4
8
12
A
22
33
45
A
0.8
V
2.0
VREF = 1.0V
V
A
-0.5
Current setting comparator
Vtatt00
ATT1 = L, ATT2 = L
0.191
0.200
0.209
threshold voltage
Vtatt01
ATT1 = H, ATT2 = L
0.152
0.160
0.168
V
V
(current attenuation rate switching)
Vtatt10
ATT1 = L, ATT2 = H
0.112
0.120
0.128
V
0.072
0.080
0.088
V
36
45
54
Vtatt11
ATT1 = H, ATT2 = H
Chopping frequency
Fchop
Cchop = 220pF
CHOP pin threshold voltage
VCHOPH
0.6
0.7
0.8
V
0.17
0.2
0.23
V
CHOP pin charge/discharge current
VCHOPL
Ichop
MONI pin saturation voltage
Vsatmon
7
Imoni = 1mA
kHz
10
13
A
250
400
mV
Continued on next page
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LV8712T/LV8713T Application Note
Continued from preceding page.
Parameter
Current setting
8W1-2-phase
comparator
drive
threshold
voltage
Symbol
Vtdac0_2W
Conditions
Step 0 (When initialized: channel 1
Ratings
min
typ
max
Unit
0.191
0.200
0.209
V
comparator level)
(1/32-step
Vtdac1_8W
Step 1 (Initial state+1)
0.191
0.200
0.209
V
at LV8713T)
Vtdac2_8W
Step 2 (Initial state+2)
0.191
0.200
0.209
V
Vtdac3_8W
Step 3 (Initial state+3)
0.189
0.198
0.207
V
Vtdac4_8W
Step 4 (Initial state+4)
0.187
0.196
0.205
V
Vtdac5_8W
Step 5 (Initial state+5)
0.185
0.194
0.203
V
Vtdac6_8W
Step 6 (Initial state+6)
0.183
0.192
0.201
V
Vtdac7_8W
Step 7 (Initial state+7)
0.179
0.188
0.197
V
Vtdac8_8W
Step 8 (Initial state+8)
0.175
0.184
0.193
V
Vtdac9_8W
Step 9 (Initial state+9)
0.171
0.180
0.189
V
Vtdac10_8W
Step 10 (Initial state+10)
0.167
0.176
0.185
V
Vtdac11_8W
Step 11 (Initial state+11)
0.163
0.172
0.181
V
Vtdac12_8W
Step 12 (Initial state+12)
0.158
0.166
0.174
V
Vtdac13_8W
Step 13 (Initial state+13)
0.152
0.160
0.168
V
Vtdac14_8W
Step 14 (Initial state+14)
0.146
0.154
0.162
V
Vtdac15_8W
Step 15 (Initial state+15)
0.140
0.148
0.156
V
Vtdac16_8W
Step 16 (Initial state+16)
0.132
0.140
0.148
V
Vtdac17_8W
Step 17 (Initial state+17)
0.126
0.134
0.142
V
Vtdac18_8W
Step 18 (Initial state+18)
0.118
0.126
0.134
V
Vtdac19_8W
Step 19 (Initial state+19)
0.112
0.120
0.128
V
Vtdac20_8W
Step 20 (Initial state+20)
0.102
0.110
0.118
V
Vtdac21_8W
Step 21 (Initial state+21)
0.094
0.102
0.110
V
Vtdac22_8W
Step 22 (Initial state+22)
0.086
0.094
0.102
V
Vtdac23_8W
Step 23 (Initial state+23)
0.078
0.086
0.094
V
Vtdac24_8W
Step 24 (Initial state+24)
0.068
0.076
0.084
V
Vtdac25_8W
Step 25 (Initial state+25)
0.060
0.068
0.076
V
Vtdac26_8W
Step 26 (Initial state+26)
0.050
0.058
0.066
V
Vtdac27_8W
Step 27 (Initial state+27)
0.040
0.048
0.056
V
Vtdac28_8W
Step 28 (Initial state+28)
0.032
0.040
0.048
V
Vtdac29_8W
Step 29 (Initial state+29)
0.022
0.030
0.038
V
Vtdac30_8W
Step 30 (Initial state+30)
0.012
0.020
0.028
V
Vtdac31_8W
Step 31 (Initial state+31)
0.002
0.010
0.018
V
Vtdac0_4W
Step 0 (When initialized: channel 1
0.191
0.200
0.209
V
(current step
switching)
4W1-2-phase
comparator level)
drive
(1/16-step
Vtdac2_4W
Step 2 (Initial state+1)
0.191
0.200
0.209
V
at LV8713T)
Vtdac4_4W
Step 4 (Initial state+2)
0.187
0.196
0.205
V
Vtdac6_4W
Step 6 (Initial state+3)
0.183
0.192
0.201
V
Vtdac8_4W
Step 8 (Initial state+4)
0.175
0.184
0.193
V
Vtdac10_4W
Step 10 (Initial state+5)
0.167
0.176
0.185
V
Vtdac12_4W
Step 12 (Initial state+6)
0.158
0.166
0.174
V
Vtdac14_4W
Step 14 (Initial state+7)
0.146
0.154
0.162
V
Vtdac16_4W
Step 16 (Initial state+8)
0.132
0.140
0.148
V
Vtdac18_4W
Step 18 (Initial state+9)
0.118
0.126
0.134
V
Vtdac20_4W
Step 20 (Initial state+10)
0.102
0.110
0.118
V
Vtdac22_4W
Step 22 (Initial state+11)
0.086
0.094
0.102
V
Vtdac24_4W
Step 24 (Initial state+12)
0.068
0.076
0.084
V
Vtdac26_4W
Step 26 (Initial state+13)
0.050
0.058
0.066
V
Vtdac28_4W
Step 28 (Initial state+14)
0.032
0.040
0.048
V
Vtdac30_4W
Step 30 (Initial state+15)
0.012
0.020
0.028
V
Continued on next page
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LV8712T/LV8713T Application Note
Continued from preceding page.
Parameter
Current setting
2W1-2-phase
comparator
drive (1/8-step
threshold
at LV8712T)
voltage
(current step
switching)
W1-2-phase
Symbol
Vtdac0_2W
Conditions
Step 0 (When initialized: channel 1
Ratings
min
typ
max
Unit
0.191
0.2
0.209
V
comparator level)
Vtdac4_2W
Step 4 (Initial state+1)
0.187
0.196
0.205
V
Vtdac8_2W
Step 8 (Initial state+2)
0.175
0.184
0.193
V
Vtdac12_2W
Step 12 (Initial state+3)
0.158
0.166
0.174
V
Vtdac16_2W
Step 16 (Initial state+4)
0.132
0.140
0.148
V
Vtdac20_2W
Step 20 (Initial state+5)
0.102
0.110
0.118
V
Vtdac24_2W
Step 24 (Initial state+6)
0.068
0.076
0.084
V
Vtdac28_2W
Step 28 (Initial state+7)
0.032
0.040
0.048
V
Vtdac0_W
Step 0 (When initialized: channel 1
0.191
0.200
0.209
V
drive
comparator level)
(quarter-step
Vtdac8_W
Step 8 (Initial state+1)
0.175
0.184
0.193
V
at LV8712T)
Vtdac16_W
Step 16 (Initial state+2)
0.132
0.140
0.148
V
Vtdac24_W
Step 24 (Initial state+3)
0.068
0.076
0.084
V
Vtdac0_H
Step 0 (When initialized: channel 1
0.191
0.200
0.209
V
1-2 phase drive
(half-step at
comparator level)
LV8712T/13T)
Vtdac16_H
Step 16 (Initial state+1)
0.132
0.140
0.148
V
2 phase drive
Vtdac16_F
Step 16' (When initialized: channel 1
0.191
0.200
0.209
V
(full-step at
comparator level)
LV8712T/13T)
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LV8712T/LV8713T Application Note
7/35
LV8712T/LV8713T Application Note
8/35
LV8712T/LV8713T Application Note
9/35
LV8712T/LV8713T Application Note
Pin Functions
Pin No.
Pin Name
Pin Function
1
RST
Excitation reset signal input pin.
2
OE
Output enable signal input pin.
7
STEP
STEP signal input pin.
8
ATT1
Motor holding current switching pin.
9
ATT2
Motor holding current switching pin.
13
MD2
Excitation mode switching pin 2.
14
MD1
Excitation mode switching pin 1.
24
FR
CW / CCW switching signal input pin.
Equivalent Circuit
VCC
GND
4
PS
Power save signal input pin.
VCC
4
GND
16
OUT2B
Channel 2 OUTB output pin.
17
RNF2
Channel 2 current-sense resistor
18
OUT2A
Channel 2 OUTA output pin.
20
OUT1B
Channel 1 OUTB output pin.
21
RNF1
Channel 1 current-sense resistor
VM
connection pin.
20 16
23 18
connection pin.
23
OUT1A
Channel 1 OUTA output pin
21
17
GND
6
VREF
Constant current control reference
voltage input pin.
VCC
6
GND
Continued on next page.
10/35
LV8712T/LV8713T Application Note
Continued from preceding page.
Pin No.
3
Pin Name
REG5
Pin Function
Internal power supply capacitor
connection pin.
Equivalent Circuit
VM
3
GND
5
MONI
Position detection monitor pin.
VCC
5
GND
10
CHOP
Chopping frequency setting capacitor
connection pin.
VCC
GND
10
11/35
LV8712T/LV8713T Application Note
Operation description
Stepping motor control
1. Power save function
This IC is switched between standby and operating mode by setting the PS pin. In standby mode, the IC is
set to power-save mode and all logic is reset. In addition, the internal regulator circuit does not operate in
standby mode.
PS
Mode
Internal regulator
Low or Open
Standby mode
Standby
High
Operating mode
Operating
2. The recommended order of power supply
It is recommendable that the power supplies are turned on in the following order.
VCC power supply → VM power supply → PS pin = High
For turning off the power supplies, the order should be reversed.
However, the above-mentioned order is presented only as a recommendation, and noncompliance is not
going to be the cause of over-current or IC destruction.
3. STEP pin function
Input
Operating mode
PS
STP
Low
*
Standby mode
High
Excitation step proceeds
High
Excitation step is kept
STEP input advances electrical angle at every rising edge (advances step by step).
STEP input MIN pulse width (common in H/L): 500ns (MAX input frequency: 1MHz)
However, constant current control is performed by PWM during chopping period, which is set by the
capacitor connected between CHOP and GND. You need to perform chopping more than once per step.
For this reason, for the actual STEP frequency, you need to take chopping frequency and chopping
count into consideration.
For example, if chopping frequency is 50kHz (20s) and chopping is performed twice per step, the
maximum STEP frequency is obtained as follows: f=1/ (20μs×2) = 25kHz.
4. Input timing
TstepH TstepL
STEP
Tdh
Tds
(md1 step) (step md1)
MD1
Tdh
Tds
(md2 step) (step md2)
MD2
Tdh
Tds
(fr step) (step fr)
FR
TstepH/TstepL: Clock H/L pulse width (min 500ns)
Tds: Data set-up time (min 500ns)
Tdh: Data hold time (min 500ns)
Figure 20. Input timing chart
12/35
LV8712T/LV8713T Application Note
5. Microstepping mode setting function (initial position)
<LV8712T>
MD1
MD2
Microstepping
Resolution
Excitation mode
Initial position
Channel 1
Channel 2
Low
Low
Full Step
2 Phase
100%
-100%
High
Low
Half Step
1-2 Phase
100%
0%
Low
High
Quarter Step
W1-2 Phase
100%
0%
High
High
1/8 Step
2W1-2 Phase
100%
0%
<LV8713T>
MD1
MD2
Microstepping
Resolution
Excitation mode
Initial position
Channel 1
Channel 2
Low
Low
Full Step
2 Phase
100%
-100%
High
Low
Half Step
1-2 Phase
100%
0%
Low
High
1/16 Step
4W1-2 Phase
100%
0%
High
High
1/32 Step
8W1-2 Phase
100%
0%
This is the initial position of each excitation mode in the initial state after power-on and when the counter is reset.
6. Initial Position monitoring function
MONI pin monitors the initial position which is open drain.
When the excitation is in the initial position, the MONI output is turned on.
(Refer to " (13) Examples of current waveforms in the respective excitation modes.")
7. Reset function
RST
Operating mode
High
Normal operation
Low
Reset state
RST
RESET
STEP
MONI
1ch output
0%
2ch output
Initial position
Figure 21. Reset function timing chart
When the RST pin is Low, the excitation position of the output is forcibly set to the initial position, and the
MONI output is turned on. When RST turns High, the excitation position is advanced by the next STEP
input.
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LV8712T/LV8713T Application Note
8. Output enable function
OE
Operating mode
Low
Output ON
High
Output OFF
OE
Power save mode
STEP
MONI
1ch output
0%
2ch output
Output is high-impedance
Figure 22. Output enable function timing chart
When the OE pin is High, the output turns OFF by force and turns to high impedance. However, since the
internal logic circuits are under operation, the excitation position proceeds when the STEP signal is input.
Therefore, when OE turns Low again, the output level follows the excitation position led by the STEP input.
9. Forward/reverse switching function
FR
Operating mode
Low
Clockwise (CW)
High
Counter-clockwise (CCW)
FR
CW mode
CCW mode
CW mode
STEP
Excitation position
(1)
(2)
(3)
(4)
(5)
(6)
(5)
(4)
(3)
(4)
(5)
1ch output
2ch output
Figure 23. Forward/Reverse switching function timing chart
The internal D/A converter proceeds by one bit at the rising edge of the input STEP pulse.
In addition, CW and CCW mode are switched by setting the FR pin.
In CW mode, the channel 2 current phase is delayed by 90° relative to the channel 1 current.
In CCW mode, the channel 2 current phase is advanced by 90° relative to the channel 1 current.
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LV8712T/LV8713T Application Note
10. Constant current control setting
The setting of STM driver's constant current control is determined by the following based on the VREF
voltage and the resistor connected between RNF and GND.
IOUT = (VREF/5) /RNF resistance
* The above formula gives setting value where the output current is100% in each excitation mode.
If VREF is open or the setting is out of the recommendation operating range, output current will increase
and you cannot set constant current under normal condition. Hence, make sure that VREF is set in
accordance with the specification.
However, if current control is not performed (if the IC is used by saturation drive or used without current limit
at DCM) make sure that the setting is as follows: VREF=5V or VREF=VREG5
Power dissipation of RF resistor is obtained as follows: Pd=Iout2×RF. Make sure to take allowable power
dissipation into consideration when you select RF resistor.
The voltage input to the VREF pin can be switched to four-step settings depending on the statuses of the
two inputs, ATT1 and ATT2. This is effective for reducing power consumption when motor holding current
is supplied.
Attenuation function for VREF input voltage
ATT1
ATT2
Current setting reference voltage attenuation ratio
Low
Low
100%
High
Low
80%
Low
High
60%
High
High
40%
The formula is given below which is used to calculate the output current when using the function for
attenuating the VREF input voltage.
IOUT = (VREF/5) × (attenuation ratio) /RNF resistance
Example: At VREF of 1.0V and a reference voltage setting is 100% [(ATT1, ATT2) = (L, L)] and an RNF
resistance of 0.5, the output current is set as follows.
IOUT = 1.0V/5 × 100%/0.5 = 400mA
If (ATT1, ATT2) is set to (H, H) in this state, IOUT is obtained as follows:
IOUT = 400mA × 40% = 160mA
In this way, the output current is attenuated when the motor holding current is supplied for power
saving.
5ms/div
Figure 24. Constant current control
(Attenuation function) waveform
ATT2
5V/div
[LV8713T]
Vcc=5V, VM=12V
VREF=1V, RNF=0.51Ω
PS=High, RST=High, ATT1=Low
MD1=MD2=High, fSTEP=10 kHz
Iout1
0.2A/div
Iout2
0.2A/div
Att ratio 100%
Att ratio 60%
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LV8712T/LV8713T Application Note
11. Chopping frequency setting
For constant-current control, this IC performs chopping operations at the frequency determined by the
capacitor (Cchop) connected between the CHOP pin and GND.
The chopping frequency is set as shown below by the capacitor (Cchop) connected between the CHOP pin
and GND.
Tchop ≈Cchop × Vtchop × 2 / Ichop (s)
Vtchop: Width of threshold voltage (VchopH-VchopL), typ 0.5V
Ichop: Charge/discharge current, typ 10A
Fchop ≈1 / Tchop (Hz)
For instance, when Cchop is 220pF, the chopping frequency will be as follows:
Fchop =1/Tchop= 10A/ (220pF × 0.5V × 2) = 45 kHz
The higher the chopping frequency is, the greater the output switching loss becomes. As a result, heat
generation issue arises. The lower the chopping frequency is, the lesser the heat generation becomes.
However, current ripple occurs. Since noise increases when switching of chopping takes place, you need to
adjust frequency with the influence to the other devices into consideration. The frequency range should be
between 40 kHz and 125 kHz.
12. Output current vector locus (one step is normalized to 90 degrees)
Figure 25.Output current vector
16/35
LV8712T/LV8713T Application Note
Setting current ration in each Microstepping mode
STEP
LV8713T selectable
1/32 Step
Ch- 1
(%)
LV8712T selectable
1/16 Step
1/8 Step
LV8712T/LV8713T selectable
Quarter Step
Half Step
Full Step
Ch- 2
(%)
Ch- 1
(%)
Ch- 2
(%)
Ch- 1
(%)
Ch- 2
(%)
Ch- 1
(%)
Ch- 2
(%)
Ch- 1
(%)
Ch- 2
(%)
100
0
100
0
100
0
100
0
100
10
98
20
98
20
96
29
92
38
92
38
92
38
88
47
83
55
83
55
77
63
70
70
70
70
70
70
70
70
63
77
55
83
55
83
47
88
38
92
38
92
38
92
29
96
20
98
20
98
10
100
0
100
0
100
0
100
0
100
0
100
0
1
100
5
2
100
10
3
99
15
4
98
20
5
97
24
6
96
29
7
94
34
8
92
38
9
90
43
10
88
47
11
86
51
12
83
55
13
80
60
14
77
63
15
74
67
16
70
70
17
67
74
18
63
77
19
60
80
20
55
83
21
51
86
22
47
88
23
43
90
24
38
92
25
34
94
26
29
96
27
24
97
28
20
98
29
15
99
30
10
100
31
5
100
32
0
100
Ch- 1
(%)
Ch- 2
(%)
100
100
17/35
LV8712T/LV8713T Application Note
13. Typical current waveform in each excitation mode
Figure 26. Full-Step resolution (FR=”Low”)
STEP
MONI
（％）
I1
100
0
（％）－100
100
I2
0
－100
Figure 27. Half-Step resolution (FR=”Low”)
STEP
MONI
(%)
100
I1
0
－100
(%)
100
I2
0
－100
18/35
LV8712T/LV8713T Application Note
Figure 28. Quarter-Step resolution (FR=”Low”)
(LV8712T)
STEP
MONI
(%)
100
I1
0
－100
(%)
100
I2
0
－100
Figure 29. 1/8-Step resolution (FR=”Low”)
(LV8712T)
STEP
MONI
[%]
100
50
I1
0
-50
-100
[%]
100
50
I2
0
-50
-100
19/35
LV8712T/LV8713T Application Note
Figure 30. 1/16-Step resolution (FR=”Low”)
(LV8713T)
STEP
MONI
[%]
100
50
I1
0
-50
-100
[%]
100
50
I2
0
-50
-100
Figure 31. 1/32-Step resolution (FR=”Low”) (LV8713T)
20/35
LV8712T/LV8713T Application Note
14. Constant Current control (Chopping operation)
(Sine wave increasing direction)
STEP
Set current
Set current
Coil current
Chopping cycle
fchop
BLANKING section
BLANKING section
Current mode CHARGE
SLOW
FAST
CHARGE
SLOW
FAST
(Sine wave decreasing direction)
STEP
Set current
Coil current
Set current
Chopping cycle
fchop
Chopping cycle
BLANKING section
Current mode CHARGE
SLOW
FAST
BLANKING section
Forced CHARGE
section
FAST
CHARGE
BLANKING section
SLOW
Figure 32. Constant current control timing chart
In each current mode, the operation sequence is as described below:
 At rise of chopping frequency, the CHARGE mode begins. (The Blanking section in which the CHARGE
mode is forced regardless of the magnitude of the coil current (ICOIL) and set current (IREF) exists for
1s.)
 The coil current (ICOIL) and set current (IREF) are compared in this blanking time.
When (ICOIL < IREF) state exists;
The CHARGE mode up to ICOIL  IREF, then followed by changeover to the SLOW DECAY mode,
and finally by the FAST DECAY mode for approximately 1s.
When (ICOIL < IREF) state does not exist;
The FAST DECAY mode begins. The coil current is attenuated in the FAST DECAY mode till one
cycle of chopping is over.
Above operations are repeated. Normally, the SLOW (+FAST) DECAY mode continues in the sine wave
increasing direction, then entering the FAST DECAY mode till the current is attenuated to the set level and
followed by the SLOW DECAY mode.
21/35
LV8712T/LV8713T Application Note
15. Output transistor operation
Charge increases
current
Switch from Charge to
Slow Decay
Current regeneration by
Slow Decay
4.
5. FAST
6.
VM
VM
VM
OFF
OFF
U1
OFF
U2
ON
ON
L2
RF
U2
OUTB
OUTA
OFF
L1
L2
OFF
OFF
L1
RF
Switch from Slow Decay
to Fast Decay
OFF
U1
OUTB
OUTA
OFF
L1
OFF
U2
U1
OUTB
OUTA
ON
L2
RF
Switch from Fast Decay
to Charge
Current regeneration by
Fast Decay
Figure 33 . Output transistor operation sequence
This IC controls constant current by performing chopping to output transistor.
As shown above, by repeating the process from 1 to 6, setting current is maintained.
Chopping consists of 3 modes: Charge/ Slow decay/ Fast decay. In this IC, for switching mode (No.2, 4, 6),
there are “off period” in upper and lower transistor to prevent crossover current between the transistors. This
off period is set to be constant (≈ 0.375s) which is controlled by the internal logic. The diagrams show
parasitic diode generated due to structure of MOS transistor. When the transistor is off, output current is
regenerated through this parasitic diode.
Output FET control function
OUTA→OUTB (CHARGE)
Output Tr
U1
U2
L1
L2
OUTB→OUTA (CHARGE)
Output Tr
U1
U2
L1
L2
CHARGE
ON
OFF
OFF
ON
SLOW
OFF
OFF
ON
ON
FAST
OFF
ON
ON
OFF
CHARGE
OFF
ON
ON
OFF
SLOW
OFF
OFF
ON
ON
FAST
ON
OFF
OFF
ON
22/35
LV8712T/LV8713T Application Note
10ms/div
Figure 34.Constant current control
waveform [LV8713T]
STEP
5V/div
Vcc=5V, VM=12V
VREF=1V, RNF=0.51Ω, Cchop=220pF
PS=High, RST=High, ATT1=ATT2=Low
MD1=High, MD2=Low, fSTEP=100Hz
Motor Current
0.2A/div
Increase
Decrease
Stationary
CHOP
1V/div
10us/div
Motor Current
0.1A/div
FAST
CHOP
0.5V/div
CHARG
SLOW
Figure 35. Constant current control waveform (Stationary state)
Motor current switches to Fast Decay mode when triangle wave (CHOP) switches from Discharge to Charge.
Approximately after 1μs, the motor current switches to Charge mode. When the current reaches to the setting
current, it is switched to Slow Decay mode which continues over the Discharge period of triangle wave.
20us/div
20us/div
STEP
5V/div
STEP
5V/div
Set Current
Set Current
Motor Current
0.1A/div
CHARG
Motor Current
0.1A/div
FAST
CHOP
0.5V/div
Figure 36. Constant current control waveform
(Increasing direction)
CHOP
0.5V/div
Figure 37. Constant current control waveform
(Decreasing direction)
23/35
LV8712T/LV8713T Application Note
16. Blanking time
If, when exercising PWM constant-current chopping control over the motor current, the mode is switched
from decay to charge, the recovery current of the parasitic diode may flow to the current sensing resistance,
causing noise to be carried on the current sensing resistance pin, and this may result in false over current
detection. To prevent this false detection, a blanking time is provided to prevent the noise occurring during
mode switching from being received. During this time, the mode is not switched from charge to decay even
if noise is carried on the current sensing resistance pin.
The blanking time, tBLANK (μs), is approximately
tBLANK≈1μs
Figure 38.Blanking time waveform
[LV8713T]
Vcc=5V, VM=12V
VREF=5V, RNF=1V, CCHOP=220pF
PS=High,
5us/div
1.5us
OUT1A
5V/div
OUT1B
5V/div
CHOP
0.5V/div
From the above Fig., the blanking time appears to be 1.5μs. However, since the mode shifts from charge
(blanking time), OFF, to DECAY, the actual blanking time is obtained as follows:
Blanking time=1μs + OFF zone = 0.5μs
24/35
LV8712T/LV8713T Application Note
17. Microstepping mode switching operation
When Microstepping mode is switched while the motor is rotating, each drive mode operates with the
following sequence.
FR＝“Low”
Before the Microstepping mode
changes
Microstepping
Step angle
mode
0-1
2-3
4-5
6-7
8-9
10-11
12-13
14-15
1/32 Step
16-17
Resolution
18-19
20-21
22-23
24-25
26-27
28-29
30-31
32
0
2
4
6
8
10
12
14
1/16 Step
16
Resolution
18
20
22
24
26
28
30
32
0
4
8
12
1/8 Step
16
Resolution
20
24
28
32
0
8
Quarter Step
16
Resolution
24
32
0
Half Step
16
Resolution
32
Full Step
16’
Resolution
Position after the Microstepping mode is changed
1/32 Step
1/16 Step
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
-30
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
-31
1
5
9
13
17
21
25
29
-31
1
9
17
25
-31
1
17
-31
17
2
6
10
14
18
22
26
30
-30
2
10
18
26
-30
2
18
-30
18
1/8 Step
4
4
8
8
12
12
16
16
20
20
24
24
28
28
32
32
-28
4
4
8
8
12
12
16
16
20
20
24
24
28
28
32
32
-28
4
12
20
28
-28
4
20
-28
20
Quarter Step
8
8
8
8
16
16
16
16
24
24
24
24
32
32
32
32
-24
8
8
8
8
16
16
16
16
24
24
24
24
32
32
32
32
-24
8
8
16
16
24
24
32
32
-24
8
24
-24
24
Half Step
16
16
16
16
16
16
16
16
32
32
32
32
32
32
32
32
-16
16
16
16
16
16
16
16
16
32
32
32
32
32
32
32
32
-16
16
16
16
16
32
32
32
32
-16
16
16
32
32
-16
Full Step
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
-16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
16’
-16’
16’
16’
16’
16’
16’
16’
16’
16’
-16’
16’
16’
16’
16’
-16’
16’
16’
-16’
32
*As for 0 to 32, please refer to the step position of current ratio setting.
25/35
LV8712T/LV8713T Application Note
If you switch Microstepping mode while the motor is driving, the mode setting will be reflected from the
next STEP and the motor advances to the position shown in the following.
(a) Microstepping (1/32-,1/16-,1/8-,Quarter-.Half-step) → Microstepping (1/32-,1/16-,1/8-,Quarter-.Half-step)
When a microstepping switches to the next microstepping, the excitation position is switched to the next
corresponding step angle of the next microstepping mode.
e.g.) When the rotation direction is forward at 1/16-step (θ6) and if you switch to 1/8 step, the step angle is
set to θ8 at the next step.
When the rotation direction is forward at 1/16-step (θ20) and if you switch to 1/8 step, the step angle is
set to θ24 at the next step.
(b) Microstepping (1/32-,1/16-,1/8-,Quarter-.Half-step) → Full-step
When a microstepping switches to the full-step, the excitation position is switched to full-step angle of the
present quadrant. Caution is required when switching from θ16 or higher step angle of microstepping position
to full-step.
e.g.) When the rotation direction is forward at 1/8 step (θ8) and if you switch to full-step, the step angle is set
to θ16’ at the next step.
When the rotation direction is forward at 1/8 step (θ16) and if you switch to full-step, the step angle is set
to θ16’ at the next step. (the electric angle is the same but the absolute value changes)
When the rotation direction is forward at 1/8 step (θ24) (the electric angle returns and the absolute value
changes)
(c) Full-step → Microstepping (1/32-,1/16-,1/8-,Quarter-.Half-step)
When full step switches to microstepping, the excitation position is switched to the next corresponding step
angle.
e.g.) When the rotation direction is forward at Full step (θ16’) and if you switch to 1/8 step, the step angle
is set to θ20 at the next step.
Microstep mode switching operation
[LV8712T]
Vcc=5V, VM=12V
VREF=1V,RNF=0.51Ω
PS=High, RST=High, fSTEP=100Hz
Figure 39
Figure 40.
Microstepping (1/8step) → Microstepping (quarter step) Microstepping (Half-step) → Microstepping (1/8 step)
MD2=High
MD1=High
θ0
θ4
1/8 step
θ8
θ12
θ16 θ24
θ32
Quarter step
MD1
5V/div
MD2
5V/div
MONI
5V/div
MONI
5V/div
Iout1
0.2A/div
Iout1
0.2A/div
Iout2
0.2A/div
Iout2
0.2A/div
θ0
θ16 θ32 -θ16 -θ12 -θ8 -θ4
Half step
1/8 step
26/35
LV8712T/LV8713T Application Note
Figure 41
Microstepping (quarter step) → Full step
MD1=Low
θ0
θ8
Quarter step
θ16 θ16’ -θ16’
Full step
Figure 42.
Full step → Microstepping (quarter step)
MD1=Low
MD2
5V/div
MD2
5V/div
MONI
5V/div
MONI
5V/div
Iout1
0.2A/div
Iout1
0.2A/div
Iout2
0.2A/div
Iout2
0.2A/div
θ16’ -θ16’ -θ8
Full step
-θ0
Quarter step
Thermal shutdown function
The thermal shutdown circuit is incorporated and the output is turned off when junction temperature Tj
exceeds 180C. As the temperature falls by hysteresis, the output turned on again (automatic restoration).
The thermal shutdown circuit does not guarantee the protection of the final product because it operates
when the temperature exceed the junction temperature of Tjmax=150C.
TSD = 180C (typ)
TSD = 40C (typ)
27/35
LV8712T/LV8713T Application Note
Application Circuit Example
The formulae for setting the constants in the examples of the application circuits above are as follows:
Constant current (100%) setting
When VREF = 1.0V
IOUT = VREF/5/RNF resistance
= 1.0V/5/0.47 = 0.426A
Chopping frequency setting
Fchop = Ichop/ (Cchop × Vtchop × 2)
= 10A/ (180pF × 0.5V × 2) = 55 kHz
28/35
LV8712T/LV8713T Application Note
Allowable power dissipation
Evaluation board
Size: 57mm x 57mm x 1.7mm, glass epoxy 2-layer board
Pd max - Ta
1.5
Allowable power dissipation, Pd max - W
1.35
1.0
0.70
0.5
Specified circuit board :
57.0 × 57.0 × 1.7mm3
2-layer glass epoxy board
0
- 20
0
20
40
60
80
100
Ambient temperature, Ta - C
Evaluation board Design Diagram
TOP View
29/35
LV8712T/LV8713T Application Note
Evaluation board
1. Completed PCB with Devices
The evaluation board of LV8712T and LV8713T is common.
PCB size: 57mm57mm1.7mm, glass epoxy 2-layer board
M
C4
R2
R3
“VCC”
Power Supply
“VM”
Power Supply
IC1
C3
C1
C2
“VREF”
Power Supply
R1
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
Clock input
Logic input
2. Bill of Materials for LV8712T/13T Evaluation Board
Designator
Quantity
Description
REG5
stabilization
Capacitor
Capacitor to
set
chopping
frequency
C1
1
C2
1
C3
1
C4
1
R1
1
R2
1
R3
1
VCC Bypass
Capacitor
VM Bypass
Capacitor
Pull-up
Resistor for
for pin MONI
Channel 1
output current
detective
Resistor
Channel 2
output current
detective
Resistor
IC1
1
Motor Driver
Manufacturer
Manufacturer Part
Number
Substitution
Allowed
Lead
Free
±10%
Murata
GRM188R72A104KA35*
Yes
Yes
±5%
Murata
GRM1882C1H181JA01*
Yes
Yes
±10%
Murata
SUN Electronic
Industries
GRM188R72A104KA35*
Yes
Yes
50ME10HC
Yes
Yes
Value
Tolerance
0.1µF,
100V
180pF,
50V
0.1µF,
100V
10µF,
50V
Footprint
±20%
47kΩ,
1/10W
±5%
KOA
RK73B1JT**473J
Yes
Yes
0.47Ω,
1W
±5%
ROHM
MCR100JZHJLR47
Yes
Yes
0.47Ω,
1W
±5%
ROHM
MCR100JZHJLR47
Yes
Yes
No
Yes
TSSOP24
(225mil)
SW1-SW8
8
Switch
ON
Semiconductor
MIYAMA
ELECTRIC
TP1-TP21
21
Test Point
MAC8
LV8712T
LV8713T
MS-621C-A01
Yes
Yes
ST-1-3
Yes
Yes
30/35
LV8712T/LV8713T Application Note
3. Evaluation board circuit
Logic
input
SW1
SW2
1
RST
FR
Logic input
24
SW4
2
OE
3
OUT1A
23
REG5
PGND
22
4
PS
RNF1
21
5
MONI
OUT1B
20
6
VREF
VM
19
7
STEP
OUT2A
18
8
ATT1
RNF2
17
9
ATT2
OUT2B
16
C1:0.1μF
Logic input
"MONI"Initial
position monitor
"VREF"
Constant current
control reference
voltage input
terminal
R2:0.47Ω
SW3
R1:47kΩ
Logic
input
SW5
C2:180pF
SW6
Motor
connection
terminal
C4:10μF
R3:0.47Ω
10 CHOP
PGND 15
11 VCC
MD1
14
12 GND
MD2
13
C3:0.1μF
"VM"
Power supply
input terminal
SW7
Logic
input
SW8
"VCC"
Power supply
input terminal
31/35
LV8712T/LV8713T Application Note
4. Evaluation Board Manual
[Supply Voltage]
VM (4 to 16V): Motor Power Supply
VCC (2.7 to 5.5V): Control Power Supply
VREF (0 to VCC-1.8V): Const. Current Control for Reference Voltage
[Toggle Switch State]
Upper Side: High (VCC)
Middle: Open, enable to external logic input
Lower Side: Low (GND)
[Operation Guide]
1. Initial Condition Setting: Set “Open or Low” all switches
2. Motor Connection: Connect the Motors between OUT1A and OUT1B, between OUT2A and
OUT2B.
3. Power Supply: Supply DC voltage to VCC, VM and VREF.
4. Ready for Operation from Standby State: Turn “High” the PS pin toggle switch. Channel 1 and
2 are into full-step excitement initial position (100%, -100%) .
5. Motor Operation: Turn “High” the RST pin toggle switch. Input the clock signal into the pin
STEP.
6. Other Setting (See Application Note for detail)
i. ATT1, ATT2: Motor current attenuation.
ii. FR: Motor rotation direction (CW / CCW) setting.
iii. MD1, MD2: Microstepping Resolution.
iv. OE: Output Enable.
[Setting for External Component Value]
1. Constant Current (100%)
At VREF=1.0V
Iout
=VREF [V] / 5 / RNF [ohm]
=1.0 [V] / 5 / 0.47 [ohm]
=0.426 [A]
2. Chopping Frequency
Fchop =Ichop [uA] / (Cchop x Vt x 2)
=10 [uA] / (180 [pF] x 0.5 [V] x 2)
=55 [kHz]
5. Evaluation Board waveform (Stepping motor drive)
LV8712T
VM=12V, VCC=5V,VREF=1.0V
PS=High,RST=High
ATT1=ATT2=FR=OE=Low
Figure 43.
Full-step (MD1=MD2=Low, fSTEP=500Hz)
Figure 44.
Half-step (MD1=High, MD2=Low, fSTEP=1 kHz)
2ms/div
2ms/div
STEP
5V/div
STEP
5V/div
MONI
5V/div
MONI
5V/div
Iout1
0.2A/div
Iout1
0.2A/div
Iout2
0.2A/div
Iout2
0.2A/div
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LV8712T/LV8713T Application Note
Figure 45.
Quarter-step (MD1=Low,MD2=High, fSTEP=2kHz)
2ms/div
Figure 46.
1/8-step (MD1=MD2=High, fSTEP=4kHz)
2ms/div
STEP
5V/div
STEP
5V/div
MONI
5V/div
MONI
5V/div
Iout1
0.2A/div
Iout1
0.2A/div
Iout2
0.2A/div
Iout2
0.2A/div
LV8713T
VM=12V, VCC=5V, VREF=1.0V
PS=High, RST=High
ATT1=ATT2=FR=OE=Low
Figure 47.
Full-step (MD1=MD2=Low, fSTEP=500Hz)
Figure 48
Half-step (MD1=High, MD2=Low, fSTEP=1 kHz)
2ms/div
2ms/div
STEP
5V/div
STEP
5V/div
MONI
5V/div
MONI
5V/div
Iout1
0.2A/div
Iout1
0.2A/div
Iout2
0.2A/div
Iout2
0.2A/div
Figure 49.
1/16-step (MD1=Low,MD2=High, fSTEP=8kHz)
Figure 50.
1/32-step (MD1=MD2=High, fSTEP=16kHz)
2ms/div
2ms/div
STEP
5V/div
STEP
5V/div
MONI
5V/div
MONI
5V/div
Iout1
0.2A/div
Iout1
0.2A/div
Iout2
0.2A/div
Iout2
0.2A/div
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LV8712T/LV8713T Application Note
Cautions for layout:
●Power supply connection pin [VM]
 VCC is a control power supply, and VM is a motor power supply.
 Make sure that supply voltage does not exceed the absolute MAX ratings under no circumstance.
Noncompliance can be the cause of IC destruction and degradation.
 Caution is required for VM supply voltage because this IC performs switching.
 The bypass capacitor of the VM power supply should be close to the IC as much as possible to stabilize
voltage. Also if you intend to use high current or back EMF is high, please augment enough capacitance.
●GND pin [GND, PGND, RNF-resistor GND line]
 High current flows into the PGND and GND side of RNF resistor; therefore, connect PGND and RNF –
GND independently.
 On the other hand, since PGND and GND are connected through silicon board, if the line of PGND is too
long, difference of electric potential occurs between PGND and GND which creates gradient to the GND
electric potential within the IC board. This can be the cause of the IC malfunction. Hence make sure to
connect PGND and RNF – GND independently so that the pins do not share the common impedance with
GND. And GND, PGND, and RNF should be single-point grounded to the low impedance GND area near
the IC. Also the capacitor between VM and GND should be connected adjacent to the IC.
●Internal power supply regulator pin [REG5]
 REG5 is a power supply to drive output FET (typ 5V).
 When VM supply is powered and PS is”High”, REG5 operates.
 Please connect capacitor for stabilize REG5. The recommendation value is 0.1uF.
 Since the voltage of REG5 fluctuates (±10%), do not use it as reference voltage that requires accuracy.
●Input pin
 The logic input pin incorporates pull-down resistor (100kΩ).
 When you set input pin to low voltage, please short it to GND because the input pin is vulnerable to noise.
 The input is TTL level (H: 2V or higher, L: 0.8V or lower).
 VREF pin is high impedance.
●OUT pin [OUT1A, OUT1B, OUT2A, OUT2B]
 During chopping operation, the output voltage becomes equivalent to VM voltage, which can be the cause
of noise. Caution is required for the pattern layout of output pin.
 The layout should be low impedance because driving current of motor flows into the output pin.
 Output voltage may boost due to back EMF. Make sure that the voltage does not exceed the absolute
MAX ratings under no circumstance. Noncompliance can be the cause of IC destruction and degradation.
●Current sense resistor connection pin [RNF1, RNF2]
 To perform constant current control, please connect resistor to RNF pin.
 To perform saturation drive (without constant current control) , please connect RNF pin to GND.
 If RNF pin is open, you cannot set constant current under normal condition. Therefore, please connect it to
resistor or GND.
 The motor current flows into RNF – GND line. Therefore, please connect it to common GND line and low
impedance line.
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LV8712T/LV8713T Application Note
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