LV8702V [ONSEMI]
PWM Current Control High-efficient Stepper Motor Driver;
| 型号： | LV8702V |
| 厂家： | 
ONSEMI |
| 描述： | PWM Current Control High-efficient Stepper Motor Driver 电动机控制 CD 光电二极管 |
| 文件： | 总27页 (文件大小：399K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LV8702V
Bi-CDMOS LSI
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PWM Current Control High-efficient
Stepper Motor Driver
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, I = 2.5A)
O
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
I max=2.5A
O
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 = 25C
Parameter
Power supply voltage
Output peak current
Output current
Symbol
max
Conditions
Ratings
Unit
V
V
VM , VM1 , VM2
36
M
I
I
peak
max
tw 10ms , duty 20% , Per 1ch
3
2.5
A
O
O
Per 1ch
A
Logic input voltage
V
GMG1, GMG2 , GAD , FR , STEP , ST ,
RST , MD1 , MD2 , OE , GST1 , GST2
0.3 to +6
V
IN
DST1, DST2, MONI,
Vdst1, Vdst2,
Pd max
Topr
0.3 to +6
5.5
V
Allowable power dissipation
Operating temperature
Storage temperature
*
W
C
C
40 to +85
55 to +150
Tstg
* 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 = 25C
Parameter
Range of power supply voltage
Logic input voltage
Symbol
Conditions
Ratings
Unit
V
V
V
VM , VM1 , VM2
9 to 32
0 to 5.5
M
GMG1 , GMG2 , GAD , FR , STEP , ST ,
RST , MD1 , MD2 , OE , GST1 , GST2
V
IN
Range of VREF input voltage
VREF
0 to 3
V
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, V = 24V, VREF = 1.5V
M
Ratings
typ
Parameter
Symbol
IMstn
Conditions
Unit
min
max
400
Consumption current during
standby
ST = ”L” , I(VM)+I(VM1)+I(VM2)
110
A
Consumption current
IM
ST = ”H”, OE = ”L”, STEP = ”L”, non-load
I(VM)+I(VM1)+I(VM2)
4.5
6.5
mA
VREG5 output voltage
Thermal shutdown temperature
Thermal hysteresis width
Motor driver
VREG5
TSD
I
= -1mA
4.5
5
180
40
5.5
V
O
Design certification
Design certification
150
210
C
C
TSD
Output on resistor
Ronu
Rond
I
I
= 2.5A, Source-side Ron
= 2.5A, Sink-side Ron
0.3
0.4
0.33
50
O
0.25
O
Output leak current
I
leak
VM = 32V
ID = -2.5A
A
V
O
Forward diode voltage
Logic pin input current
VD
1.2
8
1.4
12
I
I
L
V
V
= 0.8V
= 5V
GMG1, GMG2, GAD, FR,
STEP, ST, RST, MD1,
MD2, OE, GST1, GST2
4
A
A
IN
IN
H
30
50
70
IN
IN
ADIN pin input voltage
Vadin
Ra2 = 100k: refer to 15-4)
0
2.0
0
12
5.5
0.8
V
V
V
Logic input
voltage
High
Low
V
V
H
L
GMG1 , GMG2 , GAD , FR , STEP , ST ,
RST , MD1 , MD2 , OE , GST1 , GST2
IN
IN
Continued on next page.
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2
LV8702V
Continued from preceding page.
Ratings
typ
Parameter
Symbol
Conditions
Unit
min
290
max
310
Current
quarter step
Vtdac0_W
Vtdac1_W
Vtdac2_W
Vtdac3_W
Vtdac0_H
Vtdac2_H
Vtdac0_HF
Vtdac2’_HF
Vtdac2’_F
Fchop
Step0 (initial status, 1ch comparator level)
Step1 (initial + 1)
300
276
210
114
300
210
300
300
300
50
mV
mV
mV
mV
mV
mV
mV
mV
mV
kHz
A
selection
reference
voltage level
264
199
106
290
199
290
290
290
35
288
221
122
310
221
310
310
310
65
Step2 (initial + 2)
Step3 (initial + 3)
half step
Step0 (initial status, 1ch comparator level)
Step2 (initial + 1)
half step
Step0 (initial status, 1ch comparator level)
Step2’ (initial + 1)
(full-torque)
full step
Step2’ (initial status, 1ch comparator level)
Cchop = 200pF
Chopping frequency
CHOP pin charge/discharge
current
Ichop
7
10
13
Chopping oscillator circuit
threshold voltage
Vtup
0.8
0.4
1
1.2
0.6
V
V
Vtdown
Iref
0.5
VREF pin input current
VREF = 1.5V
0.5
A
DST1, DST2, MONI,
SST pin saturation voltage
Charge pump
Idst1 = Idst2 = Imoni = Isst = 1mA
400
mV
VG output voltage
Rise time
VG
28
90
28.7
125
29.8
0.5
V
tONG
VG = 0.1F , Between CP1-CP2 0.1uF
ST=”H” → VG=VM+4V
mS
Oscillator frequency
Fosc
160
kHz
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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3
LV8702V
Package Dimensions
unit : mm
SSOP44J (275mil) Exposed Pad
CASE 940AG
ISSUE A
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4
LV8702V
SOLDERING FOOTPRINT*
(Unit: mm)
(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
Pd max -- Ta
6.0
Four-layer circuit board *1
5.5
5.0
Four-layer circuit board *2
4.0
3.0
2.0
3.8
2.9
2.0
1.0
0
*1 With components mounted on the exposed die-pad board
*2 With no components mounted on the exposed die-pad board
--40
--20
0
20
40
60
80
100
Ambient temperature, Ta -- C
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5
LV8702V
Substrate specifications (Substrate recommended for operation of LV8702V)
Size
Material
: 90mm × 90mm × 1.6mm (Four-layer substrate)
: 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
CP2
1
2
3
4
5
6
7
8
9
44 VM
43 VG
CP1
42 PGND1
41 OUT1A
40 OUT1A
39 VM1
GMG2
GMG1
GAD
FR
38 VM1
STEP
ST
37 RF1
36 RF1
RST 10
ADIN 11
MD2 12
MD1 13
VREG5 14
DST2 15
DST1 16
MONI 17
OE 18
35 OUT1B
34 OUT1B
33 OUT2A
32 OUT2A
31 RF2
LV8702V
30 RF2
29 VM2
28 VM2
27 OUT2B
26 OUT2B
25 PGND2
24 GST1
23 GST2
SST 19
CHOP 20
VREF
SGND
21
22
Top view
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LV8702V
Block Diagram
VM
Charge pump
PGND
regulator
VREG5
Output control logic
MONI
-
-
+
+
Current
Current
(W1-2/1-2/
1-2Full/2)
(W1-2/1-2/
1-2Full/2)
+
-
attenuat
VREF
CHOP
Oscillator
SST
TSD
LVS
DST1
DST2
Signal
processor2
Signal
processor1
High-efficient drive ctrl logic
SGND
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8
LV8702V
Pin Functions
Pin No.
Pin name
SWOUT
CP2
Description
1
2
Control signal output pin
Capacitor connection pin for charge pump
Capacitor connection pin for charge pump
Driving capability margin adjuster pin
Driving capability margin adjuster pin
High-efficient drive switching pin
Forward/ reverse signal input pin
STEP signal input pin
3
CP1
4
GMG2
GMG1
GAD
5
6
7
FR
8
STEP
ST
9
Chip enable pin
10
RST
RESET signal input pin
11
ADIN
MD2
Control signal input pin
12
Excitation mode switching pin
Excitation mode switching pin
Capacitor connection pin for internal power supply
Drive status warning output pin
Drive status warning output pin
Position detection monitor pin
Output enable signal input pin
Motor stop detection output pin
13
MD1
14
VREG5
DST2
DST1
MONI
OE
15
16
17
18
19
SST
20
CHOP
VREF
SGND
GST2
GST1
PGND2
OUT2B
VM2
Capacitor connection pin for chopping frequency setting
Constant current control reference voltage input pin
Signal GND
21
22
23
Boost-up adjuster pin
24
Boost-up adjuster pin
25
2ch power GND
26, 27
28, 29
30, 31
32, 33
34, 35
36, 37
38, 39
40, 41
42
2ch OUTB output pin
2ch motor power supply connection pin
2ch current sense resistor connection pin
2ch OUTA output pin
RF2
OUT2A
OUT1B
RF1
1ch OUTB output pin
1ch current sense resistor connection pin
1ch motor power supply connection pin
1ch OUTA output pin
VM1
OUT1A
PGND1
VG
1ch power GND
43
Capacitor connection pin for charge pump
Motor power supply connection pin
44
VM
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LV8702V
Pin Description
Pin No.
Pin name
Equivalent Circuit
4
5
GMG2
GMG1
GAD
FR
VREG5
6
7
8
STEP
RST
10
12
13
18
23
24
MD2
MD1
OE
10k
GST2
GST1
100k
GND
VREG5
9
ST
20k
10k
80k
GND
25
PGND2
OUT2B
VM2
38 39
28 29
26, 27
28, 29
30, 31
32, 33
34, 35
36, 37
38, 39
40, 41
42
RF2
OUT2A
OUT1B
RF1
VM1
OUT1A
PGND1
40 41
32 33
34 35
26 27
10k
25
500
500
42
37
31
36
30
GND
Continued on next page.
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LV8702V
Continued from preceding page.
Pin No.
Pin name
Equivalent Circuit
44
2
3
CP2
CP1
VG
3
2
43
VREG5
43
44
VM
100
GND
VREG5
21
VREF
500
GND
14
VREG5
VM
2k
80k
26k
GND
15
16
17
19
DST2
DST1
MONI
SST
VREG5
100k
GND
Continued on next page.
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11
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
“L” or OPEN
“H”
mode
Internal regulator
Charge pump
Standby mode
Operation mode
standby
standby
operation
operation
2. STEP pin function
The excitation step progresses by inputting the step signal to the STP pin.
Input
Operation mode
ST
L or OPEN
H
STEP
X*
Standby mode
Excitation step forward
H
Excitation step keep
* Don’t care
3. Input timing
RST
Tds1
(RST STEP)
Tsteph Tstepl
STEP
Tds1
Tdh1
MD)
(MD STEP) (STEP
MD1/
MD2
Tds1
Tdh1
(FR
STEP) (STEP
FR)
FR
OE
Tds1
Tdh1
(OE
STEP) (STEP
OE)
Tds2
(GAD
Tdh2
STEP) (STEPGAD)
GAD
Tds2
Tdh2
(GMG
STEP) (STEPGMG)
GMG1/
GMG2
Tds2
Tdh2
(GST
STEP) (STEPGST)
GST1/
GST2
TstepH/TstepL : Clock H/L pulse width (min 12.5s)
Tds1 : Data set-up time (min 12.5s)
Tdh1 : Data hold time (min 12.5s)
Tds2 : Data set-up time (min 25s)
Tdh2 : Data hold time (min 25s)
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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:
I
= (VREF/5)/RF resistance
OUT
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.
I
= 1.5V/5/0.2 = 1.5A
OUT
When high-efficient drive function is on, I
VREF.
is adjusted automatically within the range of the current value set by
OUT
6. Reset function
RST
L or OPEN
H
Operation mode
Normal operation
RESET status
RST
RESET
STEP
MONI
1ch output
2ch output
0%
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
Output OFF
Output ON
H
L or OPEN
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
Excitation mode
1ch
2ch
-100%
0%
L or OPEN
L or OPEN
full step excitation
100%
100%
100%
100%
H
L or OPEN
H
L or OPEN
half step excitation
H
H
quarter step excitation
0%
half step excitation
(full-torque)
0%
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
L or OPEN
H
Operation mode
CW
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: 10A
Vtchop: Charge and discharge hysteresis voltage (Vtup-Vtdown) typ: 0.5V
For example, where Cchop = 200pF, we obtain Fchop as follows:
Fchop = 10A/ (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 1s.
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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
60
40
20
0
θ2
θ3
θ4
100
40
2ch phase current ratio (%)
80
0
20
60
Setting current ration in each excitation mode
STEP
quarter step (%)
half step (%)
half step full-torque (%)
1ch 2ch
full step (%)
1ch 2ch
1ch
2ch
1ch
2ch
0
1
2
3
4
100
92
70
38
0
0
38
100
70
0
0
70
100
100
0
0
100
100
70
100
100
92
100
100
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LV8702V
13. The example of current waveform in each micro-step mode
full step (CW mode)
STEP
MONI
(%)
100
l1
I2
0
-100
(%)
100
0
-100
half step full-torque (CW mode)
STEP
MONI
(%)
100
I1
I2
0
-100
(%)
100
0
-100
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LV8702V
half step (CW mode)
STEP
MONI
(%)
100
I1
I2
0
-100
(%)
100
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
Setting current
Forced CHARGE
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 1s.
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, I
is adjusted
OUT
automatically within the current value set with VREF pin. When high-efficient drive function is turned off, the current
value of I becomes the maximum value set by REF pin.
OUT
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
L or OPEN
H
Operation mode
Normal mode
High-efficient mode
(except for full step excitation mode)
Recommended speed of high-efficient drive
excitation
Operating conditions
HB motor/no-load
PM motor/no-load
HB motor/no-load
PM motor/no-load
Speed
half step
over 1500pps
over 1000pps
over 3000pps
over 2500pps
half step full-torque
quarter step
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”, I
and consumption current are at the lowest. In some case, as the I
OUT
OUT
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
L or OPEN
H
GMG2
L or OPEN
L or OPEN
H
Setting
Current consumption
Load following capability
Margin: small
Margin: middle
Margin: large
Setting is inhibited
Smallest
Smaller
Small
-
Ordinary
Good
Better
-
L or OPEN
H
H
*: This is a function to increase I
during high efficiency drive.
rapidly as soon as a possible stepping out is detected due to load variation
OUT
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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 I at once (Boost-up process). You can set a level of boost-up by
OUT
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 I
at load variation. You may be able to improve poor rotation stability with high
OUT
boost-up level by increasing high-efficient drive margin.
GST1
GST2
Setting
Increase of Iout
load following capability
Ordinary
Rotation stability
Best
L or OPEN
L or OPEN
Boost-up level minimum
{(VREF/5)/RF resistance}
1/128
H
L or OPEN
H
L or OPEN
Boost-up level low
Boost-up level high
{(VREF/5)/RF resistance}
4/128
Good
Better
Best
Better
Good
H
H
{(VREF/5)/RF resistance}
16/128
Boost-up level maximum
{(VREF/5)/RF resistance}
64/128
Ordinary
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
Ra1
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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
OFF
ON
DST2
OFF
OFF
ON
Status
Normal status
Step-out status *1(this function is enabled only in high-efficient drive)
Small step-out margin status *2(this function is enabled only in high-efficient drive)
Output short status or overheat status
OFF
ON
ON
*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 (2s), the output of 1ch/ 2ch is turned off. If the short status exceeds the timer latch time (32s) 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.
Short is detected in 2ch side.
When overheat is detected.
ON
ON
ON
ON
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 I
SST pin is turned off and high-efficient control function is enabled.
by VREF pin. And then after signal is input to STEP pin,
OUT
In this driver, the circuit constituent is as follows. By decreasing VREF voltage when the motor is stopped, I
OUT
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
"L"
Rotation
"Hi-Z"
Motor stop
"L"
Rref2
Rref1
SST output
VREF
SST
Rsst
VREF voltage
Time
1) With STEP signal where Rref1 = 30k,
Rref2 = 68k and Rsst = 5k
2) Without STEP signal where Rref1 = 30k, Rref2 = 68k,
and Rsst = 5k
VREF1 = 5V×30k/(68k+30k) 1.53V
Where VREF1 = 1.53V,
VREF2 = 5V×4.3k/(68k+4.3k) 0.3V
Where VREF2 = 0.3V
I
= VREF/5/0.22 1.39A
I
= VREF/5/0.22 0.27A
OUT
OUT
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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)
VD: voltage for diode
Ca: capacitor for filter
× Ra1/(Ra1+Ra2)
+
-
Ra1
Ca
Ra2
1
2
3
4
5
6
7
8
9
SWOUT
VM 44
VG 43
10μF
0.1μF
CP2
0.1μF
CP1
PGND1 42
OUT1A 41
OUT1A 40
VM1 39
GMG2
GMG1
GAD
FR
logic
input
VM1 38
CLOCK input
logic input
STEP
ST
RF1
37
0.22Ω
RF1 36
OUT1B 35
OUT1B 34
OUT2A 33
OUT2A 32
10 RST
11 ADIN
12 MD2
13 MD1
logic
input
M
0.1μF
0.22Ω
47kΩ 47kΩ 47kΩ
14
15
16
17
18
19
20
21
22
RF2
RF2
31
30
29
28
27
26
25
24
23
VREG5
DST2
DST1
MONI
OE
short/step-
out
detection
monitor
VM2
VM2
As for Rsst, refer to
18.current save function.
OUT2B
OUT2B
PGND2
GST2
GST2
SST
Rsst
150pF
CHOP
VREF
SGND
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
VREF = 5V×30k/(68k + 30k) ≈ 1.53V
When VREF = 1.53V :
2) Chopping frequency setting
Fchop = Ichop/(Cchop×Vtchop×2)
=10A/(150pF×0.5V×2)
66.7kHz
I
= VREF/5/0.22 1.39A
OUT
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LV8702V
ORDERING INFORMATION
Device
Package
Shipping (Qty / Packing)
2000 / Tape & Reel
SSOP44J (275mil)
(Pb-Free / Halogen-Free)
LV8702V-TLM-H
LV8702V-MPB-H
SSOP44J (275mil)
(Pb-Free / Halogen-Free)
30 / Fan-Fold
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nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including
without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can
and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each
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not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applicationsintended to support or
sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers,
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directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was
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