PWM Current Control High-efficient Stepper

LV8702V
Bi-CDMOS LSI
PWM Current Control High-efficient
Stepper Motor Driver
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Overview
The LV8702V is a 2-channel Full-bridge driver IC that can drive a stepper
motor driver, which is capable of micro-step drive and supports quarter
step. Current is controlled according to motor load and rotational speed at
half step, half step full-torque and quarter step excitation, thereby highly
efficient drive is realized. Consequently, the reduction of power
consumption, heat generation, vibration and noise is achieved.
Feature
SSOP44J (275mil)
 Built-in 1ch PWM current control stepper motor driver (bipolar type)
 Ron (High-side Ron: 0.3, Low-side Ron: 0.25, total: 0.55, Ta = 25ºC, IO = 2.5A)
 Micro-step mode is configurable as follows: full step/half step full-torque/half step/quarter step
 Excitation step moves forward only with step signal input
 Built-in output short protection circuit (latch method)
 Control power supply is unnecessary
 Built-in high-efficient drive function (supports half step full-torque/half step/quarter step excitation mode)
 Built-in step-out detection function (Step-out detection may not be accurate during high speed rotation)
 BiCDMOS process IC
 IO max=2.5A
 Built-in thermal shut down circuit
Typical Applications
 Printer
 Scanner
 Surveillance camera (CCTV)
 Textile machine
ORDERING INFORMATION
See detailed ordering and shipping information on page 27 of this data sheet.
© Semiconductor Components Industries, LLC, 2014
December 2014 - Rev. 2
1
Publication Order Number :
LV8702V/D
LV8702V
Specifications
Absolute Maximum Ratings at Ta = 25C
Parameter
Symbol
Conditions
Power supply voltage
VM max
VM , VM1 , VM2
Output peak current
IO peak
tw  10ms , duty 20% , Per 1ch
Output current
IO max
Per 1ch
Logic input voltage
VIN
Ratings
Unit
36
GMG1, GMG2 , GAD , FR , STEP , ST ,
V
3
A
2.5
A
0.3 to +6
V
RST , MD1 , MD2 , OE , GST1 , GST2
0.3 to +6
V
5.5
W
Topr
40 to +85
C
Tstg
55 to +150
C
DST1, DST2, MONI,
Vdst1, Vdst2,
Allowable power dissipation
Pd max
Operating temperature
Storage temperature
*
* Specified board : 90.0mm  90.0mm  1.6mm, glass epoxy 4-layer board, with backside mounting.
.
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 those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed,
damage may occur and reliability may be affected.
Recommended Operating Range at Ta = 25C
Parameter
Symbol
Range of power supply voltage
VM
Logic input voltage
VIN
Conditions
Ratings
Unit
VM , VM1 , VM2
9 to 32
V
GMG1 , GMG2 , GAD , FR , STEP , ST ,
0 to 5.5
V
0 to 3
V
RST , MD1 , MD2 , OE , GST1 , GST2
Range of VREF input voltage
VREF
Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended
Operating Ranges limits may affect device reliability.
Electrical Characteristics at Ta = 25°C, VM = 24V, VREF = 1.5V
Parameter
Consumption current during
Symbol
Conditions
Ratings
min
typ
Unit
max
IMstn
ST = ”L” , I(VM)+I(VM1)+I(VM2)
110
400
A
IM
ST = ”H”, OE = ”L”, STEP = ”L”, non-load
4.5
6.5
mA
standby
Consumption current
I(VM)+I(VM1)+I(VM2)
VREG5 output voltage
VREG5
IO = -1mA
4.5
5
5.5
V
Thermal shutdown temperature
TSD
Design certification
150
180
210
C
Thermal hysteresis width
TSD
Design certification
40
Ronu
IO = 2.5A, Source-side Ron
0.3
0.4
0.25
0.33

50
A
1.2
1.4
V
4
8
12
A
30
50
70
A
C
Motor driver
Output on resistor
Rond
IO = 2.5A, Sink-side Ron
Output leak current
IOleak
VM = 32V
Forward diode voltage
VD
ID = -2.5A
Logic pin input current
IINL
VIN = 0.8V
GMG1, GMG2, GAD, FR,
IINH
VIN = 5V
STEP, ST, RST, MD1,
ADIN pin input voltage
Vadin
Ra2 = 100k: refer to 15-4)
Logic input
High
VINH
GMG1 , GMG2 , GAD , FR , STEP , ST ,
voltage
Low
VINL
RST , MD1 , MD2 , OE , GST1 , GST2

MD2, OE, GST1, GST2
0
12
V
2.0
5.5
V
0.8
V
0
Continued on next page.
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LV8702V
Continued from preceding page.
Parameter
Current
quarter step
selection
reference
voltage level
half step
half step
Symbol
Conditions
Ratings
min
typ
Unit
max
Vtdac0_W
Step0 (initial status, 1ch comparator level)
290
300
310
mV
Vtdac1_W
Step1 (initial + 1)
264
276
288
mV
Vtdac2_W
Step2 (initial + 2)
199
210
221
mV
Vtdac3_W
Step3 (initial + 3)
106
114
122
mV
Vtdac0_H
Step0 (initial status, 1ch comparator level)
290
300
310
mV
Vtdac2_H
Step2 (initial + 1)
199
210
221
mV
Vtdac0_HF
Step0 (initial status, 1ch comparator level)
290
300
310
mV
mV
(full-torque)
Vtdac2’_HF
Step2’ (initial + 1)
290
300
310
full step
Vtdac2’_F
Step2’ (initial status, 1ch comparator level)
290
300
310
mV
Chopping frequency
Fchop
Cchop = 200pF
35
50
65
kHz
CHOP pin charge/discharge
Ichop
7
10
13
A
current
Chopping oscillator circuit
Vtup
0.8
1
1.2
V
threshold voltage
Vtdown
0.4
0.5
0.6
V
VREF pin input current
Iref
400
mV
29.8
V
0.5
mS
160
kHz
DST1, DST2, MONI,
0.5
VREF = 1.5V
A
Idst1 = Idst2 = Imoni = Isst = 1mA
SST pin saturation voltage
Charge pump
VG output voltage
VG
Rise time
tONG
28
28.7
VG = 0.1F , Between CP1-CP2 0.1uF
ST=”H” → VG=VM+4V
Oscillator frequency
Fosc
90
125
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be
indicated by the Electrical Characteristics if operated under different conditions.
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LV8702V
Package Dimensions
unit : mm
SSOP44J (275mil) Exposed Pad
CASE 940AG
ISSUE A
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4
LV8702V
1.00
SOLDERING FOOTPRINT*
(Unit: mm)
7.00
(3.6)
(7.8)
0.65
0.32
NOTES:
1. The measurements are for reference only, and unable to guarantee.
2. Please take appropriate action to design the actual Exposed Die Pad and Fin portion.
3. After setting, verification on the product must be done.
(Although there are no recommended design for Exposed Die Pad and Fin portion Metal mask and shape
for Through−Hole pitch (Pitch & Via etc), checking the soldered joint condition and reliability verification of
soldered joint will be needed. Void gradient insufficient thickness of soldered joint or bond degradation
could lead IC destruction because thermal conduction to substrate becomes poor.)
*For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor
Soldering and Mounting Techniques Reference Manual, SOLDERRM/D.
GENERIC
MARKING DIAGRAM*
XXXXXXXXXX
YMDDD
XXXXX = Specific Device Code
Y = Year
M = Month
DDD = Additional Traceability Data
Allowable power dissipation, Pd max -- W
6.0
Pd max -- Ta
Four-layer circuit board *1
5.5
5.0
4.0
Four-layer circuit board *2
3.8
3.0
2.9
2.0
2.0
1.0
*1 With components mounted on the exposed die-pad board
*2 With no components mounted on the exposed die-pad board
0
--40
--20
0
20
40
60
80
Ambient temperature, Ta -- C
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100
LV8702V
Substrate specifications (Substrate recommended for operation of LV8702V)
Size
: 90mm × 90mm × 1.6mm (Four-layer substrate)
Material
: Glass epoxy
Copper wiring density : L1 = 85%, L2 = 90%
L1: Copper wiring pattern diagram
L2: Copper wiring pattern diagram
L3: GND layer
L4: Power supply layer
Cautions
1) The data for the case with the Exposed Die-Pad substrate mounted shows the values when 90% or more of the
Exposed Die-Pad is wet.
2) For the set design, employ the derating design with sufficient margin.
Stresses to be derated include the voltage, current, junction temperature, power loss, and mechanical stress such as
vibration, impact, and tension.
Accordingly, the design must ensure these stresses to be as low or small as possible.
The guideline for ordinary derating is shown below:
(1)Maximum value 80% or less for the voltage rating
(2)Maximum value 80% or less for the current rating
(However this does not apply to high efficiency drive because operating current is lower than the setting current.)
(3)Maximum value 80% or less for the temperature rating
3) After the set design, be sure to verify the design with the actual product.
Confirm the solder joint state and verify also the reliability of solder joint for the Exposed Die-Pad, etc.
Any void or deterioration, if observed in the solder joint of these parts, causes deteriorated thermal conduction,
possibly resulting in thermal destruction of IC.
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LV8702V
Pin Assignment
SWOUT
1
44 VM
CP2
2
43 VG
CP1
3
42 PGND1
GMG2
4
41 OUT1A
GMG1
5
40 OUT1A
GAD
6
39 VM1
FR
7
38 VM1
STEP
8
37 RF1
ST
9
36 RF1
RST 10
35 OUT1B
ADIN 11
MD2 12
34 OUT1B
LV8702V
MD1 13
33 OUT2A
32 OUT2A
VREG5 14
31 RF2
DST2 15
30 RF2
DST1 16
29 VM2
MONI 17
28 VM2
OE 18
27 OUT2B
SST 19
26 OUT2B
CHOP 20
25 PGND2
VREF 21
24 GST1
SGND 22
23 GST2
Top view
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LV8702V
Block Diagram
RF2
OUT2B
OUT2A
VM2
VM1
OUT1B
OUT1A
RF1
VG
CP1
CP2
VM
Charge pump
Pre-output
Pre-output
regulator
VREG5
Pre-output
Pre-output
PGND
Output control logic
MONI
+
VREF
CHOP
+
-
+
Current
(W1-2/1-2/
1-2Full/2)
attenuat
Current
(W1-2/1-2/
1-2Full/2)
Oscillator
SST
TSD
DST1
LVS
Signal
processor2
Signal
processor1
High-efficient drive ctrl logic
DST2
SGND
8
GAD
OE
RST
STEP
FR
MD2
MD1
GST2
GST1
GMG2
GMG1
SWOUT
ADIN
ST
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LV8702V
Pin Functions
Pin No.
Pin name
Description
1
SWOUT
Control signal output pin
2
CP2
Capacitor connection pin for charge pump
3
CP1
Capacitor connection pin for charge pump
4
GMG2
Driving capability margin adjuster pin
5
GMG1
Driving capability margin adjuster pin
6
GAD
High-efficient drive switching pin
7
FR
Forward/ reverse signal input pin
8
STEP
STEP signal input pin
Chip enable pin
9
ST
10
RST
RESET signal input pin
11
ADIN
Control signal input pin
12
MD2
Excitation mode switching pin
13
MD1
Excitation mode switching pin
14
VREG5
Capacitor connection pin for internal power supply
15
DST2
Drive status warning output pin
16
DST1
Drive status warning output pin
17
MONI
Position detection monitor pin
18
OE
Output enable signal input pin
19
SST
Motor stop detection output pin
20
CHOP
Capacitor connection pin for chopping frequency setting
21
VREF
Constant current control reference voltage input pin
22
SGND
Signal GND
23
GST2
Boost-up adjuster pin
24
GST1
Boost-up adjuster pin
2ch power GND
25
PGND2
26, 27
OUT2B
2ch OUTB output pin
28, 29
VM2
2ch motor power supply connection pin
30, 31
RF2
2ch current sense resistor connection pin
32, 33
OUT2A
2ch OUTA output pin
34, 35
OUT1B
1ch OUTB output pin
36, 37
RF1
1ch current sense resistor connection pin
38, 39
VM1
1ch motor power supply connection pin
40, 41
OUT1A
1ch OUTA output pin
42
PGND1
1ch power GND
43
VG
Capacitor connection pin for charge pump
44
VM
Motor power supply connection pin
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LV8702V
Pin Description
Pin No.
Pin name
4
GMG2
5
GMG1
6
GAD
7
FR
8
STEP
10
RST
12
MD2
13
MD1
18
OE
23
GST2
24
GST1
Equivalent Circuit
VREG5
10k
100k
GND
9
ST
VREG5
20k
10k
80k
GND
25
PGND2
26, 27
OUT2B
28, 29
VM2
30, 31
RF2
32, 33
OUT2A
34, 35
OUT1B
36, 37
RF1
38, 39
VM1
40, 41
OUT1A
42
PGND1
38 39
28 29
40 41
34 35
32 33
26 27
10k
500
25 42
500
36 37
30 31
GND
Continued on next page.
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LV8702V
Continued from preceding page.
Pin No.
Pin name
2
CP2
3
CP1
43
VG
44
VM
Equivalent Circuit
44
3
VREG5
2
43
100
GND
21
VREF
VREG5
500
GND
14
VREG5
VM
2k
80k
26k
GND
15
DST2
16
DST1
17
MONI
19
SST
VREG5
100k
GND
Continued on next page.
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LV8702V
Continued from preceding page.
Pin No.
20
Pin name
Equivalent Circuit
CHOP
VREG5
500
500
GND
1
SWOUT
VM
PGND1
PGND2
11
ADIN
VM
2pF
2k
2pF
100k
GND
22
SGND
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LV8702V
Operation description
Input Pin Function
Each input terminal has the function to prevent the flow of the current from an input to a power supply.
Therefore, even if a power supply(VM) is turned off in the state that applied voltage to an input terminal,
the electric current does not flow into the power supply.
1. Chip enable function
The mode of the IC is switched with ST pin between standby and operation mode. In standby mode, the IC is set to
power saving mode and all the logics are reset. During standby mode, the operation of the internal regulator circuit and
the charge pump circuit are stopped.
ST
mode
Internal regulator
Charge pump
“L” or OPEN
Standby mode
standby
standby
“H”
Operation mode
operation
operation
2. STEP pin function
The excitation step progresses by inputting the step signal to the STP pin.
Input
Operation mode
ST
STEP
L or OPEN
X*
Standby mode
H
Excitation step forward
H
Excitation step keep
* Don’t care
3. Input timing
RST
Tds1
(RSTSTEP)
Tsteph Tstepl
STEP
Tds1
Tdh1
(MDSTEP) (STEPMD)
MD1/
MD2
Tdh1
Tds1
(FRSTEP) (STEPFR)
FR
Tdh1
Tds1
(OESTEP) (STEPOE)
OE
Tds2
Tdh2
(GADSTEP) (STEP GAD)
GAD
Tds2
Tdh2
(GMGSTEP) (STEPGMG)
GMG1/
GMG2
Tds2
Tdh2
(GSTSTEP) (STEP GST)
GST1/
GST2
TstepH/TstepL : Clock H/L pulse width (min 12.5s)
Tds1 : Data set-up time (min 12.5s)
Tdh1 : Data hold time (min 12.5s)
Tds2 : Data set-up time (min 25s)
Tdh2 : Data hold time (min 25s)
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LV8702V
4. Position detection monitor function
The MONI position detection monitoring pin is of an open drain type.
When the excitation position is in the initial position, the MONI output is placed in the ON state.
(Refer to "Examples of current waveforms in each micro-step mode.")
5. Setting constant-current control reference current
This IC is designed to automatically exercise PWM constant-current chopping control for the motor current by setting
the output current. Based on the voltage input to the VREF pin and the resistance connected between RF and GND, the
output current that is subject to the constant-current control is set using the calculation formula below:
IOUT = (VREF/5)/RF resistance
The above setting is the output current at 100% of each excitation mode.
For example, where VREF=1.5V and RF resistance 0.2, we obtain output current as follows.
IOUT = 1.5V/5/0.2 = 1.5A
When high-efficient drive function is on, IOUT is adjusted automatically within the range of the current value set by
VREF.
6. Reset function
RST
Operation mode
L or OPEN
Normal operation
H
RESET status
RST
RESET
STEP
MONI
1ch output
0%
2ch output
Initial position
When RST pin = “H”, the excitation position of the output is set to the initial position forcibly and MONI output is
turned on. And then by setting RST = “L”, the excitation position moves forward with the next step signal.
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LV8702V
7. Output enable function
OE
Operation mode
H
Output OFF
L or OPEN
Output ON
OE
Power save mode
STEP
MONI
1ch output
0%
2ch output
The output is in high-impedance state.
When OE pin = “H”, the output is turned off forcibly and becomes a high-impedance output.
However, since the internal logic circuit is in operation, an excitation position moves forward if step signal is input to
STEP pin. Therefore, by setting back to OE = “L”, the output pin outputs signal based on the excitation position by
step signal.
8. Excitation mode setting function
MD1 and MD2 pin set excitation mode of the stepper motor as follows.
Initial position
MD1
MD2
L or OPEN
L or OPEN
full step excitation
half step excitation
100%
0%
quarter step excitation
100%
0%
half step excitation
100%
0%
H
L or OPEN
L or OPEN
H
H
H
Excitation mode
1ch
2ch
100%
-100%
(full-torque)
The position of excitation mode is set to the initial position when: 1) a power is supplied and 2) counter is reset in each
excitation mode.
During full step excitation mode, high-efficient drive function is turned off even when GAD = “H”.
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LV8702V
9. Forward/reverse switching function
FR
Operation mode
L or OPEN
CW
H
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
The built-in DA converter moves forward by 1bit with the rise of step signal that is input to STEP pin.
Also a mode is switched between CW and CCW by setting FR pin.
In CW mode, the phase of 2ch current delays by 90° compared to that of 1ch current.
In CCW mode the phase of 2ch current moves forward by 90° compared to 1ch current.
10. Chopping frequency setting
When you control constant current of this IC, chopping is performed using the frequency defined in the capacitor
(Cchop) connected between CHOP pin and GND.
The calculation for the value of chopping frequency is:
Fchop = Ichop/ (Cchop×Vtchop×2) (Hz)
Ichop: Capacitor charge and discharge current typ: 10A
Vtchop: Charge and discharge hysteresis voltage (Vtup-Vtdown) typ: 0.5V
For example, where Cchop = 200pF, we obtain Fchop as follows:
Fchop = 10A/ (200pF×0.5V×2) = 50kHz
11. Blanking time
If you attempt to control PWM constant current chopping of the motor current, when the mode shifts from DECAY to
CHARGE, noise is generated in sense resistor pin due to the recovery current of parasitic diode flowing into current
sense resistor, and this may cause error detection. The blanking time avoids noise at mode switch. During the blanking
time, even if noise is generated in sense resistor, a mode does not switch from CHARGE to DECAY.
In this IC, the blanking time is fixed to approximately 1s.
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LV8702V
12. Output current vector locus (1step is normalized to 90)
100
,
θ2 (full step, half step full-torque)
θ0
θ1
80
1ch phase current ratio (%)
θ2
60
40
θ3
20
0
θ4
0
40
20
80
60
100
2ch phase current ratio (%)
Setting current ration in each excitation mode
STEP
quarter step (%)
1ch
half step (%)
2ch
1ch
0
100
0
1
92
38
2
70
70
3
38
92
4
0
100
half step full-torque (%)
2ch
1ch
full step (%)
2ch
1ch
100
0
100
0
70
70
100
100
0
100
0
100
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2ch
100
100
LV8702V
13. The example of current waveform in each micro-step mode
full step (CW mode)
STEP
MONI
(%)
100
l1
0
-100
(%)
100
I2
0
-100
half step full-torque (CW mode)
STEP
MONI
(%)
100
I1
0
-100
(%)
100
I2
0
-100
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LV8702V
half step (CW mode)
STEP
MONI
(%)
100
I1
0
-100
(%)
100
I2
0
-100
quarter step (CW mode)
STEP
MONI
(%)
100
I1
0
-100
(%)
100
I2
0
-100
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LV8702V
14. Current control operation specification
(Sine wave increase)
STEP
Setting current
Setting current
Coil current
Forced CHARGE
fchop
Current mode CHARGE
SLOW
FAST
CHARGE
SLOW
FAST
(Sine wave decrease)
STEP
Setting current
Coil current
Forced CHARGE
Setting current
fchop
Current mode CHARGE
SLOW
FAST
Forced CHARGE
FAST
CHARGE
SLOW
Each current mode is operated according to the following sequence.
 At rise of chopping frequency, the CHARGE mode begins. (In the time defined as the “blanking time,” the CHARGE
mode is forced regardless of the magnitude of the coil current (ICOIL) and set current (IREF).)
 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.
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LV8702V
15. High-efficient drive function
This IC includes high-efficient drive function. When high-efficient drive function is turned on, IOUT is adjusted
automatically within the current value set with VREF pin. When high-efficient drive function is turned off, the current
value of IOUT becomes the maximum value set by REF pin.
1) High-efficient drive enable function
High-efficient drive function is switched on and off with GAD pin.
However, in the case of full step excitation mode (MD1 = MD2 = “L”), even when GAD = “H”, high-efficient drive
function is turned off.
Even if you adjust the GMG1, GMG2 of 15-2) and GST1, GST2 of 15-3), in the case of abrupt motor acceleration
or load variation to the extent that auto adjuster cannot follow up and eventually leads to the rotation stepping-out,
it is recommended that you turn off the high-efficient drive function temporally. As high-efficient control may
become unstable due to the control signal from the motor is unstable during low speed rotation, it is also
recommended to turn off this function as well.
GAD
Operation mode
L or OPEN
Normal mode
H
High-efficient mode
(except for full step excitation mode)
Recommended speed of high-efficient drive
excitation
Operating conditions
Speed
half step
HB motor/no-load
over 1500pps
half step full-torque
PM motor/no-load
over 1000pps
quarter step
HB motor/no-load
over 3000pps
PM motor/no-load
over 2500pps
When there is a load, the high-efficient drive is enabled at slower speed.
2) High-efficient drive margin adjuster function
By setting GMG1 and GMG2 pin, margin for step-out is adjusted.
Where GMG1 = GMG2 = “L”, IOUT and consumption current are at the lowest. In some case, as the IOUT
becomes lower, the number of boost-up process* may increase triggered by slight change of load. With insufficient
driving capability, you need to increase the margin setting. One way to set GMG1 and GMG2 is to minimize
boost-up level, then lower the margin from high to low to optimize the margin where motor rotates stably.
In the application where load variation is excessive, you need to have a larger margin.
GMG1
GMG2
Setting
Current consumption
Load following capability
L or OPEN
H
L or OPEN
Margin: small
Smallest
Ordinary
L or OPEN
Margin: middle
Smaller
Good
L or OPEN
H
Margin: large
Small
Better
H
H
Setting is inhibited
-
-
*: This is a function to increase IOUT rapidly as soon as a possible stepping out is detected due to load variation
during high efficiency drive.
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LV8702V
3) Boost-up adjuster function
During high-efficient drive, boost-up adjuster function detects a possibility of step-out caused by such factors as
abrupt load variation and then boosts up IOUT at once (Boost-up process). You can set a level of boost-up by
setting GST1 and GST2 pins. One way to set GST1 and GST2 is to increase boost-up level from minimum to
maximum within the maximum load condition and select the optimum boost-up setting where motor rotates without
stepping out. Also, boost-up level varies depends on reference current defined by VREF. Therefore, you can
increase load following capability by increasing VREF voltage.
The higher the boost-up level is, the more the IC becomes tolerant for abrupt load variation. However, rotation
stability may become poor (vibration and rotation fluctuation may occur) because excessively high boost-up level
leads to rapid increase of IOUT at load variation. You may be able to improve poor rotation stability with high
boost-up level by increasing high-efficient drive margin.
GST1
GST2
Setting
Increase of Iout
load following capability
Rotation stability
L or OPEN
L or OPEN
Boost-up level minimum
{(VREF/5)/RF resistance}
Ordinary
Best
Good
Better
Better
Good
Best
Ordinary
 1/128
H
L or OPEN
Boost-up level low
{(VREF/5)/RF resistance}
 4/128
L or OPEN
H
Boost-up level high
{(VREF/5)/RF resistance}
 16/128
H
H
Boost-up level maximum
{(VREF/5)/RF resistance}
 64/128
4) External component
The resistance value of Ra1, Ra2 (control signal resistors) is adjusted in such a way as to set the maximum SWOUT
output voltage during motor rotation to 12V in ADIN pin. Preferably, resistance values of Ra1 and Ra2 are as high
as possible to the extent that does not influence waveform. (Recommendation for Ra1: 15k, Ra2: 100k).
In some motor where boost-up process occurs at a high speed rotation of 7000pps to 8000pps or higher (HB motor:
Half step excitation), you can suppress boost-up by lowering Ra1. Moreover, you can achieve high efficiency at
lower speed of 1500pps or lower by increasing resistance for Ra1 (HB motor: Half step excitation).
Although it depends on a usage motor, step-out is detectable at higher speed rotation by attaching smaller resistor
for Ra1.
SWOUT
Ra2
ADIN
Ca
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Ra1
LV8702V
5) Drive status warning function
DST1 and DST2 are open-drain output. The driving status can be monitored through a status of DST1 and DST2
pins. When step-out status is detected, DST1 is on for a period of 1 step. Likewise, when small step-out margin
status is detected, DST2 turns on for the period of 1 step. In the case of output short status or overheat status, DST1
and DST2 stay on until ST = “L”.
Step-out status and small step-out margin status are detectable during high-efficient drive only. In some cases,
step-out status may not be detected properly. Hence, make sure to verify the operation with the usage application.
If step-out or small step-out margin status occur frequently, make sure to set a large high-efficient drive margin or
higher boost-up level.
DST1
DST2
Status
OFF
OFF
Normal status
ON
OFF
Step-out status *1(this function is enabled only in high-efficient drive)
OFF
ON
Small step-out margin status *2(this function is enabled only in high-efficient drive)
ON
ON
Output short status or overheat status
*1: Although it depends on a usage motor, step-out is detectable at higher speed rotation by attaching smaller
resistor for Ra1.
*2: If DST2 alone is turned on, boost-up processing is performed.
16. Output short protection circuit
Output short protection circuit is included in this IC which sets an output to standby mode and turns on warning output.
This protection circuit prevents IC destruction when the output is short due to power short or ground short.
1) Operation overview
When output short is detected, short detection circuit operates. If the short status continues for the period of internal
timer (2s), the output of 1ch/ 2ch is turned off. If the short status exceeds the timer latch time (32s) set in the
internal timer, the output is turned on again and detects short status again. If short is detected again, all the output of
1ch/ 2ch are switched to standby mode and the status is kept. To cancel the standby status, set
ST = “L”.
2) Error status warning output pin (DST2, DST1)
When the IC detects error status and protection circuit operates, DST2 pin and DST1 pin outputs the error status to
CPU side.
This pin is open-drain output. When error status is detected, DST2 and DST1 output turn on (DST2 = DST1 = “L”).
DST2/DST1 pins are turned on in the following statuses:
Error status
DST2
DST1
Short is detected in 1ch side.
ON
ON
Short is detected in 2ch side.
ON
ON
When overheat is detected.
ON
ON
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LV8702V
17. Charge pump circuit
When ST pin is set to “H”, charge pump circuit operates and VG pin voltage increases from VM voltage to VM +
VREG5 voltage. If the VG pin voltage is not boosted to VM+4V or more, the output pin cannot be turned on.
Therefore it is recommended that the drive of motor is started after the time has passed tONG or more.
ST
VG pin voltage
VM+VREG5
VM+4V
VM
tONG
Fg. VG pin voltage
18. Current save function when motor is stopped
SST pin is the open-drain output. When STEP signal is not input for about 16mS, (min: 13mS, max: 23mS), SST pin
detects that the rotation of the motor is stopped and SST pin is turned on. At this time, high-efficient drive function is
turned off automatically and full current value is set for IOUT by VREF pin. And then after signal is input to STEP pin,
SST pin is turned off and high-efficient control function is enabled.
In this driver, the circuit constituent is as follows. By decreasing VREF voltage when the motor is stopped, IOUT
current can be saved. However, this function is unusable when you rotate motor at which input cycle of STEP pulse
signal is 16mS or longer.
Motor stop
Rotation
Motor stop
"Hi-Z"
Rref2
VREF
Rref1
Rsst
SST output
"L"
"L"
SST
VREF voltage
Time
1) With STEP signal where Rref1 = 30k,
Rref2 = 68k and Rsst = 5k
VREF1 = 5V×30k/(68k+30k)  1.53V
Where VREF1 = 1.53V,
IOUT = VREF/5/0.22  1.39A
2) Without STEP signal where Rref1 = 30k, Rref2 = 68k,
and Rsst = 5k
VREF2 = 5V×4.3k/(68k+4.3k)  0.3V
Where VREF2 = 0.3V
IOUT = VREF/5/0.22  0.27A
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LV8702V
19. Thermal shutdown function
The thermal shutdown circuit is included, and the output is turned off when junction temperature Tj exceeds 180°C
and the abnormal state warning output is turned on at the same time.
When the temperature falls hysteresis level, output is driven again (automatic restoration).
The thermal shutdown circuit doesn’t guarantee protection of the set and the destruction prevention of IC,
because it works at the temperature that is higher than rating (Tjmax=150°C) of the junction temperature.
TSD = 180°C (typ)
ΔTSD = 40°C (typ)
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LV8702V
Example of application circuit
Make sure that ADIN is 12V or less
since constant varies depends on
user applications.
ADIN = (VM+VD) × Ra1/(Ra1+Ra2)
VD: voltage for diode
Ca: capacitor for filter
Ra1
Ra2
+ -
1 SWOUT
VM 44
2 CP2
VG 43
3 CP1
PGND1 42
4 GMG2
OUT1A 41
5 GMG1
OUT1A 40
0.1μF
10μF
0.1μF
Ca
logic
input
6 GAD
VM1 39
7 FR
VM1 38
CLOCK input
8 STEP
RF1 37
logic input
9 ST
RF1 36
LV8702V
10 RST
11 ADIN
logic
input
0.1μF
47kΩ 47kΩ 47kΩ
short/stepout
detection
monitor
As for Rsst, refer to
18.current save function.
12 MD2
13 MD1
0.22Ω
OUT1B 35
OUT1B 34
OUT2A 33
M
OUT2A 32
14 VREG5
RF2 31
15 DST2
RF2 30
16 DST1
VM2 29
17 MONI
VM2 28
18 OE
OUT2B 27
19 SST
OUT2B 26
20 CHOP
PGND2 25
21 VREF
GST2 24
22 SGND
GST2 23
0.22Ω
Rsst
150pF
VREF
30kΩ
68kΩ
logic
input
- +
5V
Calculation for each constant setting according to the above circuit diagram is as follows.
1) Constant current (100%) setting
2) Chopping frequency setting
VREF = 5V×30k/(68k + 30k) ≈ 1.53V
Fchop = Ichop/(Cchop×Vtchop×2)
When VREF = 1.53V :
=10A/(150pF×0.5V×2)
IOUT = VREF/5/0.22  1.39A
 66.7kHz
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LV8702V
ORDERING INFORMATION
Device
LV8702V-TLM-H
Package
SSOP44J (275mil)
(Pb-Free / Halogen-Free)
LV8702V-MPB-H
SSOP44J (275mil)
(Pb-Free / Halogen-Free)
Shipping (Qty / Packing)
2000 / Tape & Reel
30 / Fan-Fold
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