LV8711T Motor Driver Application Note

LV8711T
Bi-CMOS LSI
PWM Constant-Current Control
Stepper Motor Driver
http://onsemi.com
Application Note
Overview
The LV8711T is a PWM constant-current control stepper motor driver which is low consumption, low heat
and high efficiency. The device is suited 2-cell battery applications. Its supply voltage range is from 4V to 16V,
and stand-by mode current drain is almost zero. It can contribute to reduce costs and PCB size because of
the built-in circuit to control current. It also can contribute to safe design of applications by several built-in
protection functions.
Function
 Two circuits of PWM constant-current control H-bridge drivers incorporated
 Control of the stepper motor to Half-step excitations possible
 Reference voltage output: 1.0V
 Short circuit protection circuit incorporated
 Abnormal condition warning output pin incorporated
 Upper and lower regenerative diodes incorporated
Thermal shutdown circuit incorporated
VCC Low Voltage Shut Down circuit incorporated
Typical Applications
 POS Printer
 Handy Type Scanner
 Thermal Printer Unit
 Card terminal
 Air-conditioner
Semiconductor Components Industries, LLC, 2013
December, 2013
1/28
LV8711T Application Note
Package Dimensions
unit : mm (typ)
3260A
Pd max - Ta
2.0
Allowable power dissipation, Pd max - W
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)
1.5
1.45
1.0
0.754
0.5
Specified circuit board :
57.0 × 57.0 × 1.7mm3
glass epoxy board
0
- 20
SANYO : TSSOP24(225mil)
0
20
40
60
80
100
Ambient temperature, Ta - C
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
2/28
LV8711T Application Note
Pin Assignment
VM
1
24
IN1A
NC
2
23
IN1B
REG5
3
22
OUT1A
PS
4
21
RNF1
EMO
5
20
OUT1B
VREF
6
19
VMM
LV8711T
REG1
7
18
OUT2A
ATT1
8
17
RNF2
ATT2
9
16
OUT2B
CHOP
10
15
PGND
VCC
11
14
IN2A
GND
12
13
IN2B
Figure 1. Pin Assignment
3/28
+
-
+
-
VREF
REG1
VCC
VM
GND
Standard
voltage
Start
circuit
gate for upside
output voltage
circuit
LVS
TSD
+
standard voltage
circuit
RNF1
OUT1B
Output preamplifier stage
OUT2B
Output preamplifier stage
RNF2
current switch
function
IN2A IN2B
constant
current
control
Output control logic
VMM OUT2A
PS
CHOP
Oscillator
ATT1 ATT2 IN1A IN1B
current switch
function
Output preamplifier stage
constant
current
control
Output control logic
OUT1A
Output preamplifier stage
REG5
+
EMO
PGND
LV8711T Application Note
Block Diagram
Figure 2. Block Diagram
4/28
LV8711T Application Note
Specifications
Absolute Maximum Ratings at Ta = 25C
Parameter
Symbol
Conditions
Ratings
Unit
Motor supply voltage
VM max
18
Logic supply voltage
VCC max
V
6
V
Logic input voltage
VIN
Output peak current
IO peak
Per ch, tw  10ms, duty 20%
1.0
6
V
A
Output continuous current
IO max
Per ch
800
mA
Allowable power dissipation
Pd max
*
1.45
W
Operating temperature
Topr
-20 to +85
C
Storage temperature
Tstg
-55 to +150
C
* Specified circuit board: 57.0mm57.0mm1.7mm, glass epoxy printed circuit 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
Symbol
Conditions
Ratings
min
typ
Unit
max
Motor supply voltage range
VM
4
16
V
Logic supply voltage range
VCC
2.7
5.5
V
Logic input voltage range
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 = 3.3, VREF = 1.0V
Parameter
Symbol
Conditions
Ratings
min
typ
Unit
max
General
Standby mode current drain
Current drain
IMstn
PS = “L”, no load
1
A
ICCstn
PS = “L”, no load
1
A
IM
PS = “H”, no load
1.0
1.5
mA
ICC
PS = “H”, no load
1.7
3.0
mA
Thermal shutdown temperature
TSD
Design guarantee
Thermal hysteresis width
TSD
Design guarantee
VCC low voltage cutting voltage
VthVCC
2.1
2.4
2.7
V
Low voltage hysteresis voltage
VthHYS
100
130
160
mV
VREG5
4.5
5
5.5
V
150
C
180
C
40
Reference voltage
REG5 output voltage
Output
RonU
IO = -800mA, Source-side
0.78
1.0

RonD
IO = 800mA, Sink-side
0.32
0.43

Output leakage current
IOleak
VO = 15V
10
A
Diode forward voltage
VD
ID = -800mA
1.0
1.2
V
Output on resistance
Logic input
Logic pin input current
IINL
VIN = 0.8V
4
8
12
A
IINH
VIN = 3.3V
22
33
45
A
0.8
V
Logic high-level input voltage
VINH
Logic low-level input voltage
VINL
2.0
V
Continued on next page.
5/28
LV8711T Application Note
Continued from preceding page.
Parameter
Symbol
Ratings
Conditions
min
typ
Unit
max
Constant-current control
REG1 output voltage
VREG1
VREF input current
IREF
Current setting reference voltage
0.95
VREF = 1.0V
1.0
1.05
V
A
-0.5
Vtatt00
VREF = 1.0V
0.192
0.200
0.208
V
Vtatt01
VREF = 1.0V
0.152
0.160
0.168
V
Vtatt10
VREF = 1.0V
0.092
0.100
0.108
V
0.032
0.040
0.048
36
45
54
Vtatt11
VREF = 1.0V
Chopping frequency
Fchop
Cchop = 220pF
CHOP pin threshold voltage
VCHOPH
0.6
0.7
0.8
V
VCHOPL
0.17
0.2
0.23
V
7
10
13
A
250
400
mV
CHOP pin charge/discharge current
Ichop
V
kHz
Output short-circuit protection
EMO pin saturation voltage
VsatEMO
IEMO = 1mA
3
1.2
0.9
1.5
ICC
1
0.3
ICCstn
0.5
0
2
3
0.6
0.6
IM
0.4
0
0
4
5
6
VCC (V)
Figure 3. VCC Current Drain
vs VCC Voltage
3
5.5
1.3
5
1.2
8
13
18
VM (V)
Figure 4. VM Current Drain
vs VM Voltage
1.1
VREG1 (V)
4.5
4
3.5
3
1
0.9
0.8
0.7
3
8
13
3
18
8
13
VM (V)
18
VM (V)
Figure 5. VREG5 Output Voltage
vs VM Voltage
Figure 6. VREG1 Output Voltage
vs VM Voltage
2.5
60
2
50
40
1.5
IIN (uA)
VIN (V)
0.3
Imstn
0.2
0
VREG5 (V)
0.8
IM(mA)
ICC(mA)
0.6
IMstn(uA)
1
2
ICCstn(uA)
2.5
0.9
1
VINH
0.5
30
20
10
VINL
0
0
3
8
13
VM (V)
Figure 7. Logic High/Low-Level Input
Voltage vs VM Voltage
18
0
1
2
3
4
5
VIN (V)
Figure 8. Logic Pin Input Current
vs Input Voltage
6/28
‐50
0.6
‐48
0.5
VsatEMO (mV)
Iref (nA)
LV8711T Application Note
‐46
‐44
‐42
‐40
0.4
0.3
0.2
0.1
0
0
1
2
3
0
0.5
1
IEMO (mA)
VREF (V)
1.0 1.0 0.8 0.8 0.6 0.6 0.4 Ronu
0.2 0.4 Ronu
0.2 Rond
Rond
0.0 0.0 0
0.5
1
1.5
3
8
13
18
Iout (A)
VM (V)
Figure 11. Output on Resistance
vs Output Current (VM= 12V)
Figure 12. Output on Resistance
vs VM Voltage (Iout= 0.8A)
1.2
2
1.1
1.5
1
VD (V)
Ronu+Rond (Ω)
2
Figure 10. EMO Pin Saturation Voltage
vs EMO Current
Ron (Ω)
Ron (Ω)
Figure 9. VREF Pin Input Current
vs VREF Voltage
1.5
1
0.5
0.9
0.8
VDu
0.7
0
VDd
0.6
‐30
20
70
120
Temperature(℃)
Figure 13. Output on Resistance
vs Temperature (VM=12V, Iout=0.8A)
0
0.5
1
1.5
Iout (A)
Figure 14. Diode Forward Voltage
vs Output Current
7/28
LV8711T Application Note
Pin Functions
Pin No.
Pin Name
Pin Function
8
ATT1
These pins are Motor holding current
9
ATT2
switching. Keeping the VREF voltage,
output current can be attenuated by
Equivalent Circuit
VREG5
VCC
switching these pins.
Refer to (3) on P.11 for details.
13
IN2B
14
IN2A
These pins are connected to an external
microcontroller interface. Channel 2 driver
output is controlled by switching these
pins. Refer to (2) on P.11 for details.
23
IN1B
24
IN1A
These pins are connected to an external
microcontroller interface. Channel 1 driver
output is controlled by switching these
GND
pins. Refer to (2) on P.11 for details.
4
PS
This pin switches Power Save mode.
VCC
PS = L : LV8711 is in Power Save mode.
PS = H : LV8711 is in Operating mode.
When all outputs are the stand-by state
caused by short-circuit, if PS is switched
4
to L, the state is released.
Refer to (1) on P.11 for details.
GND
16
OUT2B
One of the motor coil is connected
18
OUT2A
between these pins.
VM
Refer to P.12~19 for details.
17
RNF2
Channel 2 current sensing resistor is
connected to this pin.
20
OUT1B
One of the motor coil is connected
22
OUT1A
between these pins.
20 16
22 18
Refer to (3) on P.11 for details.
Refer to P.12~19 for details.
21
RNF1
Channel 1 current sensing resistor is
connected to this pin.
Refer to (3) on P.11 for details.
3
REG5
This pin outputs Internal reference
voltage. And a capacitor is connected to
GND
21
17
VCC
this pin.
3
GND
Continued on next page.
8/28
LV8711T Application Note
Continued from preceding page.
Pin No.
5
Pin Name
EMO
Pin Function
Equivalent Circuit
This pin outputs Abnormal condition
VCC
warning.
Connect Pull-Up resistor between this
pin and VCC. The setting range is 5kΩ to
50kΩ. Normally, it outputs H(VCC). If
LV8711 detects short-circuit or the
5
thermal shut down function operates, it
turns L.
Refer to (10) on P.20 for details.
SGND
6
VREF
This is the Constant current control
reference voltage input pin. It can be
VCC
connected to REG1. But if output current
needs high precision, it had better be
connected to another source.
Refer to (3) on P.11 for details.
6
GND
7
REG1
This pin outputs reference voltage 1 V for
Current setting. It can be connected to
VREG5
VREF directly or after devided with
resistors between REG1 and GND.
7
GND
10
CHOP
This is the chopping frequency setting
capacitor connection pin.
VCC
If larger capacitor is connected, the
frequency is lower.
If smaller capacitor is connected, the
frequency is higher.
The frequency can be checked at this pin
as the triangle wave.
Refer to (4) on P.12~13 for details.
GND
10
Continued on next page.
9/28
LV8711T Application Note
Continued from preceding page.
Pin No.
Pin Name
1
VM
11
VCC
Pin Function
Equivalent Circuit
This pin is connected to the motor supply
voltage and VMM pin 19.
This pin is connected to the logic supply
voltage and monitored by the LV8711.
The operation is inhibited when VCC is
below the minimum 2.4 V value by the
Low Voltage Shut Down function.
Refer to (11) on P.21 for details.
12
GND
The logic and low level analog signals
shall be connected to this ground pin.
This pin must be externally connected to
the PGND pin 15. The designer must
make sure no high current transients are
shared with the low signal currents
flowing into this pin.
15
PGND
This pin is the Power Ground associated
with the Power-Tr of H-Bridge and must
be connected to the system ground
together with GND pin 12. Using good
quality ground plane is recommended to
avoid spikes on the logic signal lines.
19
VMM
This pin is connected to the motor supply
voltage and VM pin 1.
10/28
LV8711T Application Note
Description of operation
Input Pin Function
(1) Chip enable function
Standby mode / operating mode of the IC are switched by setting the PS pin. In the standby-state, the IC
enters a power saving mode and all logic is reset. In the standby-state, internal regulator circuit is not
operative.
PS
Condition
Low or Open
Standby mode
Internal regulator
Standby
High
Operating mode
Operating
(2) Output control logic
Parallel input
IN1A(2A)
IN1B(2B)
Output
OUT1A(2A)
OUT1B(2B)
Current direction
Low
Low
OFF
OFF
Output OFF
High
Low
High
Low
OUTA to OUTB
Low
High
Low
High
OUTB to OUTA
High
High
Low
Low
Brake(DCM mode)
(3) Constant-current setting (In case of DCM mode, it is the Current Limit function.)
The constant-current control setting consist of the VREF voltage setting and resistor (RNF) connected
between RNF and ground. The current is set according to the following equation.
IOUT [A] = VREF [V] / 5 / RNF [Ω]
Also, the voltage applied to the VREF pin can be switched to four stages settings by the state of two inputs
of the ATT1 and ATT2 pins. This function is effective for power saving when the motor holding current is
applied.
Attenuation function of the VREF input voltage
ATT1
ATT2
Current setting reference voltage attenuation ratio
Low
Low
100%
High
Low
80%
Low
High
50%
High
High
20%
The output current calculation method for using of attenuation function of the VREF input voltage is as
below.
IOUT = (VREF / 5) х Attenuation ratio / RNF resistance
e.g. When the VREF is 1.0V and the set reference voltage is 100% [(ATT1, ATT2) = (Low, Low)] and the
RNF resistance is 0.47Ω, the following output current is set.
IOUT = 1.0V / 5 х 100% / 0.47Ω = 425mA
In this conditions, when (ATT1, ATT2) is set to (High, High),
IOUT = 425mA х 20% = 85mA
Therefore, the power saving is executable by attenuation of the output current when motor holding
current is supplied.
It is prohibited to use as below.
VREF pin is open.
VREF input voltage is more than “Allowable Operating Ratings” (VCC-1.8V).
It can’t control the constant current, if VREF is set as stated above.
If it controls in Full-swing or without current limiter, connect REG1 to VREF, and RNF1/2 to GND.
RNF dissipates power Pd as computed below. Select parts in consideration of the allowable power
dissipation.
Pd = Iout2 × RNF
11/28
LV8711T Application Note
(ATT1,ATT2) is set to (L, L)
(ATT1,ATT2) is set to (H, H)
425mA
85.2mA
IOUT1A
(200mA/div)
=425mA
IOUT1A
(50mA/div)
=85.2mA
Figure 15. Iout wave (425mA х 100%)
Figure 16. Iout wave (425mA х 20%)
(4) Setting the chopping frequency
For constant-current control, chopping operation is made with the frequency determined by the external
capacitor connected between CHOP pin 10 and GND. The chopping frequency to be set with the capacitor
is as shown below.
Chopping period: Tchop
Tchop ≈ C х V х 2 / I [s]
V: Threshold voltage
Typ, 0.5V
I : Charge / discharge current
Typ. 10μA
Chopping frequency: Fchop Fchop ≈ 1 / Tchop [Hz]
The triangle wave is appeared on CHOP pin. The chopping frequency is equal to the frequency of the
triangle wave.
The real frequency is usually lower than theory value provided by above formula because of parasitic
capacitance of PCB and so on.
The designer must set the frequency suited for the solution. If the frequency is unsuited, it may be a reason
of vibration or noise.
100pF : 71.0 kHz
180pF : 45.3 kHZ
300pF : 29.0 kHz
Every waves are
X : 10 uS/div
Y : 500 mV/div
Figure 17. Triangle waves on CHOP pin
12/28
LV8711T Application Note
The ripple of coil current depends on coil impedance or coil inductance of motor.
The ripple is different even if chopping frequency is set the same value.
FCHOP = 45.3 kHZ
Motor
FCHOP = 29.0 kHz
IOUT : 100 mA/div
IOUT : 100 mA/div
CHOP : 500 mV/div
CHOP : 500 mV/div
A
X : 10 uS/div
X : 10 uS/div
The ripple of coil current is 88 mA.
The ripple of coil current is 97 mA.
IOUT : 100 mA/div
IOUT : 100 mA/div
CHOP : 500 mV/div
Motor
CHOP : 500 mV/div
B
X : 10 uS/div
The ripple of coil current is 31 mA.
X : 10 uS/div
The ripple of coil current is 38 mA.
Figure 18. The ripple of coil current depended on FCHOP and kind of motor
If the chopping frequency is higher, IC consumes more electricity by its switching frequency, and it is getting
hotter.
If the chopping frequency is lower, the ripple of coil current is getting larger.
13/28
LV8711T Application Note
(5) Constant-current control time chart (chopping operate)
In each current mode, the operation sequence is described below:
 At first stage of chopping cycle, the IC goes to CHARGE mode. (The Blanking section in which the
CHARGE mode is forced regardless of the magnitudes of the coil current (ICOIL) and the set current
(IREF) exists for 1μs.)

In Blanking section, the IC compares the coil current (ICOIL) and the set current (IREF).
If the ICOIL < IREF state is existent in Blanking section.
Set current
Coil current
Forced CHARGE section
Chopping cycle
Current mode CHARGE
SLOW
FAST
Charge mode continues until ICOIL ≥ IREF. After the IC switches to SLOW DECAY mode and
then switches to FAST DECAY mode for the last 1μs.
If the ICOIL < IREF state is non-existent in Blanking section.
Set current
Coil current
Forced CHARGE section
Chopping cycle
Current mode CHARGE
SLOW
FAST
The IC switches to SLOW DECAY after Blanking section, and then switches to FAST DECAY
mode for the last 1μs.
The IC repeats the above operation.
14/28
LV8711T Application Note
(6) Output transistor operation mode
1) Charge
2) Slow Decay 1
3) Slow Decay 2
VMM
Tr_AU
OUT_A
OUT_B
Tr_BD
Tr_BD
Tr_AD
Tr_BD
Di_AD
RNF
1)When 2 transistors, Tr_AU
and Tr_BD are ON, coil current
flow through the coil.
At that time, output voltages
are
OUT_A : VMM - Vsat
OUT_B : 0V + Vsat + I × RF
2)When coil current has
reached the set value in Charge,
the chopping process changes
to Slow Decay 1.
At that time, output voltages
are
OUT_A : 0V – VF
(Negative potential)
OUT_B : 0V + Vsat
3)If Di_AD keeps to flow
current, the IC chip generates
heat. Then Tr_AD turns ON in
Slow Decay 2.
At that time, output voltages
are
OUT_A : 0V – Vsat
(Negative potential)
OUT_B : 0V + Vsat
4) Fast Decay 1
5) Fast Decay 2
6) Fast Decay 3
Tr_BU
Di_BU
Tr_AD
Di_BU
Tr_AD
Di_AU
4)After Slow Decay 2, Tr_BD
turns OFF. The coil current
flow through RF, Tr_AD, coil
and Di_BU to VMM.
At that time, output voltages
are
OUT_A : 0V + Vsat + I × RF
(Negative potential)
OUT_B : VMM + VF
5)If Di_BU keeps to flow
current, the IC chip generate
heat. Then Tr_BU turns ON in
Fast Decay 2.
At that time, output voltages
are
OUT_A : 0V + Vsat + I × RF
(Negative potential)
OUT_B : VMM + Vsat
6)At the end of a chopping
period or if the coil current
goes out, all transistors turn
OFF.
At that time, output voltages
are
OUT_A : 0V + VF+ I × RF
(Negative potential)
OUT_B : VMM + VF
If the coil current goes out,
both outputs voltages are Hi-Z.
*Vsat : The saturation voltage of transistor ( Tr_U : 400mV, TR_D : 150mV typical at 500mA )
VF : The forward voltage of diodes ( Di_U : 900mV, Di_D : 850mV typical at 500mA )
15/28
LV8711T Application Note
Fast Decay
Charge
Slow Decay
Fast Decay
4ch : IOUT1A
(100 mA/div)
2ch : VOUT1A
(5 V/div)
3)
1)
3ch : VOUT1B
(5 V/div)
X : 5 uS/div
3)
1)
1ch :CHOP
(500 mV/div)
Zoom in
4ch : IOUT1A
(100 mA/div)
4)
2)
2ch : VOUT1A
(5 V/div)
5)
3ch : VOUT1B
(5 V/div)
6)
X : 2 uS/div
1)
3)
1)
1ch :CHOP
(500 mV/div)
Figure 19. Output signal at each Chopping timing (STM mode)
The numbers 1), 2), 3), 4), 5) and 6) in the above figure are linked with same numbers on the previous page.
16/28
LV8711T Application Note
(7) Typical current waveform in each excitation mode
7-1) STM Drive mode
IN1A
IN1B
IN2A
IN2B
(%)
100
IOUT1
0
-100
(%)
100
IOUT2
0
-100
Figure 20. Timing chart of Full-step excitation (CW mode)
IN1A
IN1B
IN2A
IN2B
(%)
100
lOUT1
0
-100
(%)
100
lOUT2
0
-100
Figure 21. Timing chart of Half-step excitation (CW mode)
17/28
LV8711T Application Note
7-2) DCM Drive mode
IN1A(2A)
IN1B(2B)
(%)
100
lOUT1(2)
CW
BRAKE
BRAKE
0
OFF
CCW
-100
(%)
Figure 22. Timing chart of DCM mode
2 H-bridges parallel connection
2ch of H-bridge can be connected in parallel to control a large DC motor. Connect OUT1A with OUT2A,
OUT1B with OUT2B, IN1A with IN2A, IN1B with IN2B. In this case, the Current Limit function is
ineffective. Therefore connect RNF1/2 to GND. Refer to P.24 for details of connection.
Direct PWM mode
LV8711 can also control DC motors by direct PWM mode. The IC repeats Drive (CW or CCW) and
Brake or OFF. It depends on 2 input signals. Refer table below.
Output
IN1A(2A)
IN1B(2B)
CW & Brake
H
PWM
CCW & Brake
PWM
H
CW & OFF
PWM
L
CCW & OFF
L
PWM
18/28
LV8711T Application Note
*IN1A keeps H
Charge
Slow Decay
2)
3)
1)
Charge
IN1B : 5 V/div
VOUT1A : 10 V/div
2)
3)
1)
VOUT1B : 10 V/div
IOUT1A : 100 mA/div
X : 20 uS/div
CW & Brake
Figure 23. Output signal at each Chopping timing
(DCM direct PWM mode 1)
*IN1B keeps L
Fast Decay
4)
5)
6)
Charge
1)
Fast Decay
4)
5)
6)
Charge
IN1A : 5 V/div
VOUT1A : 10 V/div
1)
VOUT1B : 10 V/div
IOUT1A : 100 mA/div
X : 20 uS/div
CW & OFF
Figure 24. Output signal at each Chopping timing
(DCM direct PWM mode 2)
The numbers 1), 2), 3), 4), 5) and 6) in the above figure are linked with same numbers on the page 15.
19/28
LV8711T Application Note
(8) Output short-circuit protection
To protect IC from damage due to short-circuit of the output caused by lightening or ground fault, the output
short-circuit protection is incorporated in order to put the output in the OFF mode.
When detecting the output short-circuit state, the short-circuit protection circuit is activated.
When short-circuit state is detected ≈ 4μs (count by the internal timer), detected output is OFF at the time.
Then, when the output exceeds the timer latch time counted by the internal counter, the output is ON. Still,
the short circuit state is detected, the IC switches all output to stand-by mode and keeps the state.
This state is released by setting PS = Low.
2
Iout (A)
1.5
1
Upper
0.5
Lower
0
‐30
20
70
120
Temperature(℃)
Figure 12. Short-Circuit detect current
vs Temperature (VM= 12V)
(9) Thermal shutdown function
The thermal shutdown circuit is incorporated, and the output is turned off when junction temperature Tj
exceeds 180C, and the abnormal state warning output is turned on. 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)
(10)Abnormal condition warning output pin
EMO, warning output pin of thermal shutdown circuit and the output short-circuit protection circuit, is an
open-drain output. EMO outputs ON when output short-circuit is detected.
When detecting the output overdrive, the EMO outputs ON. If the junction temperature goes down, EMO
outputs OFF automatically.
3) 4)
1) 2)
VOUT1A
EMO
1) The Output turned on and short-circuit
happened.
2) If short-circuit state is detected ≈ 4uS,
detected output turns off temporarily.
3) The output exceeds the timer latch time,
the output is ON again.
4) Still, the short-circuit state is detected,
the IC switches all output to stand-by
mode and keeps the state.
And EMO outputs ON.
Figure 26. Timing chart of the Output short-circuit protection and EMO
20/28
LV8711T Application Note
(11)VCC Low Voltage Shut Down
The built-in comparator, associated with the band gap reference, continuously monitors the VCC input
while PS is H.
If the VCC voltage drops below 2.4 V (typical) during the operation, the LV8711 generates a Power Save
sequence and is forced into a no stand-by mode. The built-in 130 mV hysteresis avoids unstable operation
when the battery voltage slowly varies around 2.5 V.
When the VCC voltage rises above 2.53 V (typical), the chip is activated and all the functions become
available.
(12)Recommended power-on sequence
Provide a wait time of 10μs or more after VCC power supply rises before supplying VM power supply.
Provide a wait time of 10μs or more after VM power supply raises before setting the PS pin High.
VCC
VM
PS
Figure 27. Timing chart of recommended power-on sequence
The above power-on sequence is only a recommendation, and there are no risks of damage or over
current to the IC even if this sequence is not followed.
21/28
LV8711T Application Note
Typical Application Circuit
It is a bypass capacitor.
The setting range is
10uF to 100uF
（Electrolytic capacitor etc.）
It is a stabilization capacitor of
the internal regulator output
voltage.
The setting range is
0.1uF to 1uF.
1
VM
IN1A
24
2
NC
IN1B
23
3
REG5
OUT1A
22
4
PS
RNF1
21
5
EMO
OUT1B
20
6
VREF
VMM
19
7
REG1
OUT2A
18
8
ATT1
RNF2
17
9
ATT2
OUT2B
16
10
CHOP
PGND
15
11
VCC
IN2A
14
12
GND
IN2B
13
Logic input
10μF
0.1μF
It is a resistor to detect
output current.
The setting range is
0.1Ω to 1Ω.
Please refer to P.9 for details.
0.47Ω
Logic input
M
Abnormal condition sensing monitor
20kΩ
The REG1 voltage （1V） can be
used to set output current.
It can connect to VREF
directly or after divided with
resistors.
The setting range （total） is
10kΩ to 100kΩ.
Please refer to P.9 for details.
0.47Ω
It is a resistor to detect
output current,
The setting range is
0.1Ω to 1Ω.
Please refer to P.9 for details.
180pF
0.1μF
Logic input
It sets the PWM frequency.
The setting range is
100pF to 500pF.
Please refer to P.10 for details.
LV8711T
It is a pull-up resistor for
Abnormal condition sensing
monitor.
The setting range is
10kΩ to 100kΩ.
It is a bypass capacitor.
The setting range is
0.1uF to 1uF.
（Layer ceramic capacitor etc.）
Figure 28. Typical application Circuit for Stepper motor
Each constant setting method for the above circuit diagram example is as follows:
Current LIMIT (100%) set
VREF = 1.0V (when internal regulator output is connected)
ILIMIT = VREF / 5 / RNF resistance
= 1.0V / 5 / 0.47 = 425mA
Chopping frequency setting
Fchop = Ichop / (Cchop × Vt × 2)
= 10A/ (180pF × 0.5V × 2) = 55.5 kHz
22/28
LV8711T Application Note
It is a bypass capacitor.
The setting range is
10uF to 100uF
（Electrolytic capacitor etc.）
It is a stabilization capacitor of
the internal regulator output
voltage.
The setting range is
0.1uF to 1uF.
1
VM
IN1A
24
2
NC
IN1B
23
3
REG5
OUT1A
22
4
PS
RNF1
21
5
EMO
OUT1B
20
6
VREF
VMM
19
7
REG1
OUT2A
18
8
ATT1
RNF2
17
9
ATT2
OUT2B
16
10
CHOP
PGND
15
11
VCC
IN2A
14
12
GND
IN2B
13
Logic input
10μF
It is a resistor to detect
output current.
The setting range is
0.1Ω to 1Ω.
Please refer to P.9 for details.
0.1μF
0.47Ω
Abnormal condition sensing monitor
20kΩ
It is a resistor to detect
output current,
The setting range is
0.1Ω to 1Ω.
Please refer to P.9 for details.
180pF
0.1μF
Logic input
It sets the PWM frequency.
The setting range is
100pF to 500pF.
Please refer to P.10 for details.
0.47Ω
M
The REG1 voltage （1V） can be
used to set output current.
It can connect to VREF
directly or after divided with
resistors.
The setting range （total） is
10kΩ to 100kΩ.
Please refer to P.9 for details.
LV8711T
It is a pull-up resistor for
Abnormal condition sensing
monitor.
The setting range is
10kΩ to 100kΩ.
M
Logic input
It is a bypass capacitor.
The setting range is
0.1uF to 1uF.
（Layer ceramic capacitor etc.）
Figure 29. Typical application Circuit for DC motors
Each constant setting method for the above circuit diagram example is as follows:
Current LIMIT (100%) set
VREF = 1.0V (when internal regulator output is connected)
ILIMIT = VREF / 5 / RNF resistance
= 1.0V / 5 / 0.47 = 425mA
Chopping frequency setting
Fchop = Ichop / (Cchop × Vt × 2)
= 10uA/(180pF×0.5V×2)= 55.5kHz
23/28
LV8711T Application Note
It is a bypass capacitor.
The setting range is
10uF to 100uF
（Electrolytic capacitor etc.）
10μF
It is a stabilization capacitor of
the internal regulator output
voltage.
The setting range is
0.1uF to 1uF.
VM
IN1A
24
2
NC
IN1B
23
3
REG5
OUT1A
22
4
PS
RNF1
21
5
EMO
OUT1B
20
6
VREF
VMM
19
7
REG1
OUT2A
18
8
ATT1
RNF2
17
9
ATT2
OUT2B
16
10
CHOP
PGND
15
11
VCC
IN2A
14
12
GND
IN2B
13
Abnormal condition sensing monitor
M
LV8711T
20kΩ
Logic input
0.1μF
Logic input
It is a pull-up resistor for
Abnormal condition sensing
monitor.
The setting range is
10kΩ to 100kΩ.
1
0.1μF
It is a bypass capacitor.
The setting range is
0.1uF to 1uF.
（Layer ceramic capacitor etc.）
Figure 30. Typical application Circuit for 1 DC motor
In this case, the Current Limit function is ineffective. Therefore connect RNF1/2 to GND, and REG1 to VREF.
Connect OUT1A with OUT2A, OUT1B with OUT2B, IN1A with IN2A, IN1B with IN2B.
24/28
LV8711T Application Note
Evaluation Board
R2:
OUT2 Output current
Sensing resistor
M
C1:
VM Bypass
capacitor
R1:
OUT1 Output current
Sensing resistor
“VCC”
Power Supply
C3:
5VREG Stabilization
capacitor
R47
R47
“VM”
Power Supply
C4:
Capacitor to set
chopping frequency
LV8711
R3:
Pull-up resistor for
the terminal EMO
C2:
VCC Bypass
capacitor
Function generator
Figure 31. Evaluation board overview
Bill of Materials for LV8731V Evaluation Board
Designator
Quantity
C1
1
C2
1
C3
1
C4
1
R1
1
R2
1
R3
1
Description
VM Bypass
Capacitor
VCC Bypass
Capacitor
5VREG
stabilization
Capacitor
Capacitor to
set
chopping
frequency
OUT1 Output
current
Sensing
resistor
OUT2 Output
current
Sensing
Resistor
Pull-up
Resistor for
for terminal
EMO
IC1
1
Motor Driver
SW1-SW7
7
TP1-TP18
18
Value
10µF,
50V
0.1µF,
100V
Tolerance
Footprint
Manufacturer
Manufacturer Part
Number
Substitution
Allowed
Lead
Free
Yes
Yes
±20%
SUN Electronic
±10%
Murata
GRM188R72A104KA35*
Yes
Yes
0.1µF,
100V
±10%
Murata
GRM188R72A104KA35*
Yes
Yes
180pF,
50V
±5%
Murata
GRM1882C1H181JA01*
Yes
Yes
0.47Ω,
1W
±5%
ROHM
MCR100JZHJLR47
Yes
Yes
0.47Ω,
1W
±5%
ROHM
MCR100JZHJLR47
Yes
Yes
20kΩ,
1/10W
±5%
KOA
RK73B1JT**203J
Yes
Yes
ON
semiconductor
LV8711T
No
Yes
Switch
MIYAMA
MS-621C-A01
Test Point
MAC8
ST-1-3
50ME10HC
25/28
LV8711T Application Note
Evaluation Board circuit
VM
IN1A
24
2
NC
IN1B
23
3
REG5
OUT1A
22
4
PS
RNF1
21
5
EMO
OUT1B
20
6
VREF
VMM
19
7
REG1
OUT2A
18
8
ATT1
RNF2
17
9
ATT2
OUT2B
16
10
CHOP
PGND
15
11
VCC
IN2A
14
12
GND
IN2B
13
+
1
10μF
0.1μF
0.47Ω
Abnormal condition sensing monitor
LV8711T
20kΩ
0.47Ω
180pF
0.1μF
Figure 32. Evaluation Board circuit schematic
*When we started developing this IC, the Pin No.2 was the output of internal regulator (REGVM5).
But now, it is a no connection pin
Each constant setting method for the above circuit diagram example is as follows.

Current LIMIT (100%) set
VREF = 1V (when internal regulator REG1 output is connected)
Ilimit = VREF/5/RNF
=1V/5/0.47Ω= 425mA

Chopping frequency setting
Fchop = Ichop/(Cchop×Vt×2)
=10uA/(180pF×0.5V×2)= 55.5kHz
26/28
LV8711T Application Note
Operation Guide
For stepper motor control
 Connect a stepper motor with OUT1A, OUT1B, OUT2A and OUT2B.
 Connect the motor power supply with the terminal VM, the control power supply with the terminal VCC.
Connect the GND line with the terminal GND.
 Input the reference voltage to the terminal VREF. (The terminal REG1 short circuit is assumed.)
 Turn the switch of “PS” on. (Knock it down for above in follow image.)
 Keep other switches middle position. Input drive signals to IN1A, IN1B, IN2A and IN2B from DSP.
Refer to the timing charts on P.17.
For smaller DC motor(s) control
 Connect DC motor(s) between OUT1A and OUT1B, OUT2A and OUT2B.
 Connect the motor power supply with the terminal VM, the control power supply with the terminal VCC.
Connect the GND line with the terminal GND.
 Input the reference voltage to the terminal VREF. (The terminal REG1 short circuit is assumed.)
 Turn the switch of “PS” on. (Knock it down for above in follow image.)
 Turn the switch of IN1A, IN1B, IN2A and IN2B ON or OFF.
When DSP is connected to previous Input pins, keep their switches middle position.
Refer to the timing chart on P.18.
For a larger DC motor control
 Connect Output pin OUT1A with OUT2A, OUT1B with OUT2B each other directly.
 Connect Input pin IN1A with IN2A, IN1B and IN2B each other directly.
 Connect DC motor between OUT1A/2A and OUT1B/2B.
 Connect the motor power supply with the terminal VM, the control power supply with the terminal VCC.
Connect the GND line with the terminal GND.
 Connect REG1 to VREF directly.
 Turn the switch of “PS” on.（Knock it down for above in follow image.）
 Turn the switch of IN1A/2A and IN1B/2B ON or OFF.
When DSP is connected to previous Input pins, keep their switches middle position.
Refer to the timing chart on P.18.
The points of attention to design applications
 The VM, each OUT, and each RNF where a large current flows are laid out fat and short as much as
possible.
 The VM bypass capacitor is mounted as near as possible to the IC.
 Do not exceed the absolute maximum ratings under no circumstance. The terminal OUT can exceed VM
due to reversed voltage or regenerated current. Refer to P.15.
 "PGND" is ground of the power system. "GND" is small signal ground. They need to be laid out without
the common impedance.
 The island of GND needs to be noted low impedance as much as possible. For example, make
through-holes as much as possible.
 We recommend that the GND line to connect a stabilization capacitor of VCC is laid out alone to near
ground connected the VM bypass capacitor.
 VREG5 is used in the IC as reference voltage. Capacitance is connected between VREG5 pin and GND
to stabilize VREG5.
 REG1 can be used to reference voltage for Constant-current setting. Therefore REG1 can connect to
VREF directly or after devided with resistors. But if output current needs high precision, VREF had better
be connected to another source.
 VREG5 and REG1 can not be recommended to use for peripheral circuits because their output voltage
are not so high precision.
 The input pin is connected to 100k Ω pull-down in the chip. If the pin is open, the IC receives signals as
L. But it may be misunderstood when the pin is affected by noise. When the pin is input L, it is
recommended to switch to ground.
27/28
LV8711T Application Note
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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 customer application by customer’s technical experts.
SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as
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