BD68720EFV_技术文档

Datasheet

36VHigh-performance,

High-reliability Withstand Voltage

Stepping Motor Driver

BD68720EFV

●General Description

● Key Specifications

BD68720EFV is a bipolar low-consumption driver that

driven by PWM current. Rated power supply voltage of

the device is 36 V, and rated output current is 2.0 A.

PARA-IN driving mode is adopted for input interface,

and excitation mode is corresponding to FULL STEP

mode, HALF STEP mode (2 types) and QUARTER

STEP mode via a built-in DAC. In terms of current

decay, the FAST DECAY/SLOW DECAY ratio may be

set without any limitation, and all available modes may

be controlled in the most appropriate way. In addition,

the power supply may be driven by one single system,

which simplifies the design.

■

Range of power supply voltage

Rated output current (continuous)

Rated output current (peak value)

Range of operating temperature

Output ON resistance (total of

upper and lower resistors)

19～28 [V]

2.0 [A]

2.5 [A]

-25～+85 [℃]

0.65 [Ω] (Typ.)

●Package

W(Typ.) x D(Typ.)x H(Max.)

9.70mm x 6.40mm x 1.00mm

HTSSOP-B28

● Features

■

Rated output current（DC）2.0A

Low ON resistance DMOS output

PARA-IN drive mode

PWM constant current (other oscillation)

Built-in spike noise cancel function (external noise

filter is unnecessary)

■

Full-, half (two kinds)-, quarter-step functionality

Freely timing excitation mode switch

Current decay mode switch

● Typical Application circuit

（linearly variable FAST/SLOW DECAY ratio）

Normal rotation & reverse rotation switching

function

Power save function

Built-in logic input pull-down resistor

Power-on reset function

Thermal shutdown circuit (TSD)

Over-current protection circuit（OCP）

Under voltage lock out circuit (UVLO)

Over voltage lock out circuit (OVLO)

Ghost Supply Prevention (protects against

malfunction when power supply is disconnected)

Adjacent pins short protection

■

GND

9

15

■

PHASE1

PHASE2

14

PS

17

16

18

19

20

I01

I11

I02

I12

VCC1

7

VREF 13

OUT1A

5

2

OUT1B

RNF1

■

3

4

Microminiature, ultra-thin and high heat-radiation

(exposed metal type) package

RNF1S

VCC2

● Applications

22

■

PPC, multi-function printer, laser beam printer, and

ink-jet printer

Monitoring camera and WEB camera

Sewing machine

Photo printer, FAX, scanner and mini printer

Toy and robot

OUT2A

CR

10

24

27

OUT2B

RNF2

■

26

25

MTH 12

RNF2S

GND

1

Figure.1 Application circuit

○

Product structure：silicon monolithic integrated circuit ○It is not the radiation-proof design for this product.

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BD68720EFV

● Pin Configuration

[TOP VIEW]

● Block Diagram

15

TSD

OCP

PHASE1

1

28

27

26

NC

GND

17

16

PHASE2

I01

GND

PS

9

OVLO

UVLO

Translator

OUT2B

RNF2

2

3

OUT1B

RNF1

I11 18

RESET

14

19

20

I02

I12

RNF1S

OUT1A

4

5

25 RNF2S

24

＋

－

VREF 13

2bit DAC

OUT2A

VCC1

7

OUT1A

＋

－

5

2

NC

6

7

23 NC

RNF1S

RNF2S

OUT1B

RNF1

3

VCC1

＋

－

22 VCC2

4 RNF1S

Blank time

21

NC

8

NC

GND

CR

PWM control

VCC2

22

OUT2A

CR

10

24

27

9

20 I12

19 I02

OSC

OUT2B

RNF2

26

25

Mix decay

control

10

11

12

13

14

MTH 12

RNF2S

GND

NC

18

17

I11

Regulator

1

MTH

PHASE2

I01

VREF

PS

16

15

Figure.3 Block Diagram

PHASE1

Figure.2 Pin configuration

● Pin Description

Pin No.

Pin name

Function

Pin No.

15

Pin name

Function

Ground terminal

Phase selection terminal

1

GND

PHASE1

I01

H bridge output terminal

VREF division ratio setting terminal

Phase selection terminal

2

3

OUT1B

RNF1

RNF1S

OUT1A

NC

16

17

18

19

20

21

22

23

24

25

26

27

28

Connection terminal of resistor for

output current detection

PHASE2

I11

Input

comparator

terminal

of

current

limit

VREF division ratio setting terminal

Non connection

4

H bridge output terminal

Non connection

5

I02

6

I12

Power supply terminal

Non connection

7

VCC1

NC

Power supply terminal

8

VCC2

NC

Ground terminal

Non connection

9

GND

CR

Connection terminal of CR for setting

chopping frequency

H bridge output terminal

10

11

12

13

14

OUT2A

RNF2S

RNF2

OUT2B

NC

Non connection

Input terminal of current limit comparator

NC

Connection terminal of resistor for output

current detection

Current decay mode setting terminal

Output current value setting terminal

Power save terminal

MTH

VREF

PS

H bridge output terminal

Non connection

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● Absolute Maximum Ratings (Ta=25℃)

Item

Symbol

V_CC1,2

V_IN

Rated Value

-0.2～+36.0

-0.2～+5.5

0.7

Unit

Supply voltage

V

Input voltage for control pin

RNF maximum voltage

Maximum output current (DC)

V

V_RNF

I_OUT

I_OUTPEAK

T_opr

2.0

A/Phase

℃

Maximum

output

current

2.5

(PEAK)^{(Note 1)}

Operating temperature range

-25～+85

-55～+150

Storage temperature range

T_stg

℃

(Note 1)Pulse width tw≦1ms, duty 20%.

Caution: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit between

pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is operated over the absolute

maximum ratings.

●Recommended operating range (Ta= -25～+85℃)

Item

Supply voltage

Maximum Output current (DC)

Symbol

V_CC1,2

I_OUT

Rated Value

19～28

1.7

Unit

V

A/ Phase

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Thermal Resistance^{(Note 2)}

Thermal Resistance (Typ)

Parameter

Symbol

Unit

1s^{(Note 4)}

2s2p^{(Note 5)}

HTSSOP-B28

Junction to Ambient

Junction to Top Characterization Parameter^{(Note 3)}

θ_JA

107.0

6

25.1

3

°C/W

Ψ_JT

(Note 2)Based on JESD51-2A(Still-Air)

(Note 3)The thermal characterization parameter to report the difference between junction temperature and the temperature at the top center of the outside

surface of the component package.

(Note 4)Using a PCB board based on JESD51-3.

Layer Number of

Measurement Board

Material

FR-4

Board Size

Single

114.3mm x 76.2mm x 1.57mmt

Top

Copper Pattern

Thickness

Footprints and Traces

70μm

(Note 5)Using a PCB board based on JESD51-7.

Layer Number of

Material

Board Size

114.3mm x 76.2mm x 1.6mmt

2 Internal Layers

Measurement Board

4 Layers

FR-4

Top

Bottom

Copper Pattern

74.2mm x 74.2mm

Copper Pattern

Thickness

Copper Pattern

Thickness

Footprints and Traces

70μm

74.2mm x 74.2mm

35μm

70μm

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●Electrical Characteristics (Unless otherwise specified Ta=25℃, VCC1,2=24V)

Specification

Item

Symbol

Unit

Condition

Minimum Standard Maximum

[Whole]

Circuit current at standby

Circuit current

I_CCST

I_CC

-

0.8

2.0

5.0

mA

PS=L

PS=H, VREF=3V

[Control input] (PHASE1, PHASE2)

H-level input voltage

V_IN1H

V_IN1L

V_IN1HYS

I_IN1H

2.8

-

0.6

-

V

L-level input voltage

Input hysteresis voltage

H-level input current

L-level input current

-

0.85

50

0

V

35

-10

100

-

µA

V_IN1=5V

V_IN1=0V

I_IN1L

[Control input] (PS, I01, I11, I02, I12)

H-level input voltage

L-level input voltage

H-level input current

L-level input current

V_IN2H

2.0

-

0.8

100

-

V

V_IN2L

I_IN2H

I_IN2L

35

-10

50

0

µA

V_IN2=5V

V_IN2=0V

[Output (OUT1A, OUT1B, OUT2A, OUT2B)]

I

_OUT=±1.0A (total of upper and

Output ON resistance

R_ON

-

0.65

-

0.85

10

Ω

lower resistors)

Output leak current

[Current control]

I_LEAK

µA

RNFXS input current

RNFX input current

VREF input current

VREF input voltage range

MTH input current

I_RNFS

I_RNF

-2.0

-80

-2.0

0

-0.1

-40

-0.1

-

µA

V

RNFxS=0V

RNFx=0V

VREF=0V

I_VREF

V_VREF

I_MTH

-

3.0

-

-2.0

0

-0.1

-

µA

V

MTH=0V

MTH input voltage range

V_MTH

3.5

Minimum ON time

(Blank time)

t_ONMIN

V_CTH

0.3

0.7

1.5

µs

V

C=1000pF, R=39kΩ

Comparator threshold

0.57

0.60

0.63

VREF=3V

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●Function explanation

○PS/Power saving pin

PS can make circuit standby state and make motor output OPEN. When PS=L⇒H, please be careful because there is a

delay of 40μs (max.) before it is returned from standby state to normal state and the motor output becomes ACTIVE.

PS

State

Standby state(RESET)

ACTIVE

L

H

○PHASE1, PHASE2/Phase selection terminal

This is the pin to decide output logic.

PHASE1

PHASE2

OUT1A

OUT1B

OUT2A

OUT2B

L

H

L

H

L

H

L

H

L

H

L

H

L

○I01,I02,I11,I12 / VREF division ratio setting pin

These terminals determine internal 2bit-DAC output voltage for current limit.

I0x

L

I1x

L

Output current level (%)

100

67

33

0

H

L

H

(I0X, I1X)=(H, H): motor outputs are open.

○VCC1,VCC2／Power supply terminal

Motor’s drive current is flowing in it, so please wire in such a way that the wire is thick & short and has low impedance.

Voltage VCC may have great fluctuation, so please arrange the bypass capacitor of about 100μ～470μF as close to the

terminal as possible and adjust in such a way that the voltage VCC is stable. Please increase the capacity if needed

especially when a large current is used or those motors that have great back electromotive force are used. In addition, for

the purpose of reducing of power supply’s impedance in wide frequency bandwidth, parallel connection of multi-layered

ceramic capacitor of 0.01μ～0.1μF etc is recommended. Extreme care must be used to make sure that the voltage VCC

does not exceed the rating even for a moment. VCC1 & VCC2 are shorted inside IC, so please be sure to short externally

VCC1 & VCC2 when using. If used without shorting, malfunction or destruction may occur because of concentration of

current routes etc., so please make sure that they are shorted when in use. Still more, in the power supply terminal, there is

built-in clamp component for preventing of electrostatic destruction. If steep pulse or voltage of surge more that maximum

absolute rating is applied, this clamp component operates, as a result there is the danger of destruction, so please be sure

that the maximum absolute rating must not be exceeded. It is effective to mount a Zener diode of about the maximum

absolute rating. Moreover, the diode for preventing of electrostatic destruction is inserted between VCC terminal and GND

terminal, as a result there is the danger of IC destruction if reverse voltage is applied between VCC terminal and GND

terminal, so please be careful.

○GND／Ground terminal

In order to reduce the noise caused by switching current and to stabilize the internal reference voltage of IC, please wire in

such a way that the wiring impedance from this terminal is made as low as possible to achieve the lowest electrical potential

no matter what operating state it may be.

○OUT1A,OUT1B,OUT2A,OUT2B／H Bridge output terminal

Motor’s drive current is flowing in it, so please wire in such a way that the wire is thick & short and has low impedance. It is

also effective to add a Schottky diode if output has positive or negative great fluctuation when large current is used etc, for

example, if counter electromotive voltage etc. is great. Moreover, in the output terminal, there is built-in clamp component

for preventing of electrostatic destruction. If steep pulse or voltage of surge more than maximum absolute rating is applied,

this clamp component operates, as a result there is the danger of even destruction, so please be sure that the maximum

absolute rating must not be exceeded.

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○RNF1,RNF2／Connection terminal of resistor for detecting of output current

Please connect the resistor of 0.1Ω～0.3Ω for current detection between this terminal and GND. In view of the power

consumption of the current-detecting resistor, please determine the resistor in such a way that W=IOUT2･R[W] does not

exceed the power dissipation of the resistor. In addition, please wire in such a way that it has a low impedance and does

not have a impedance in common with other GND patterns because motor’s drive current flows in the pattern through RNF

terminal～current-detecting resistor～GND. Please do not exceed the rating because there is the possibility of circuits’

malfunction etc. if RNF voltage has exceeded the maximum rating (0.7V). Moreover, please be careful because if RNF

terminal is shorted to GND, large current flows without normal PWM constant current control, then there is the danger that

OCP or TSD will operate. If RNF terminal is open, then there is the possibility of such malfunction as output current does

not flow either, so please do not let it open.

○RNF1S,RNF2S／Input terminal of current limit comparator

In this series, RNFS terminal, which is the input terminal of current limit comparator, is independently arranged in order to

decrease the lowering of current-detecting accuracy caused by the wire impedance inside the IC of RNF terminal.

Therefore, please be sure to connect RNF terminal and RNFS terminal together when using in the case of PWM constant

current control. In addition, because the wires from RNFS terminal is connected near the current-detecting resistor in the

case of interconnection, the lowering of current-detecting accuracy, which is caused by the impedance of board pattern

between RNF terminal and the current-detecting resistor, can be decreased. Moreover, please design the pattern in such a

way that there is no noise plunging. In addition, please be careful because if terminals of RNF1S & RNF2S are shorted to

GND, large current flows without normal PWM constant current control and, then there is the danger that OCP or TSD will

operate.

○VREF／Output current value setting terminal

This is the terminal to set the output current value. The output current value can be set by VREF voltage and

current-detecting resistor (RNF resistor).

Output current IOUT [A] = {VREF [V] / 5(division ratio inside IC)} / RNF [Ω]

Please avoid using it with VREF terminal open because if VREF terminal is open, the input is unsettled, and the VREF

voltage increases, and then there is the possibility of such malfunctions as the setting current increases and a large current

flows etc. Please keep to the input voltage range because if the voltage of over 3V is applied on VREF terminal, then there

is also the danger that a large current flows in the output and so OCP or TSD will operate. Besides, please take into

consideration the outflow current (max.2μA) if inputted by resistance division when selecting the resistance value. The

minimum current, which can be controlled by VREF voltage, is determined by motor coil’s L & R values and minimum ON

time because there is a minimum ON time in PWM drive.

○CR／Connection terminal of CR for setting chopping frequency

This is the terminal to set the chopping frequency of output. Please connect the external C(470p～1500pF) and R(10k～

200kΩ) between this terminal and GND. Please refer to P9.

Please interconnect from external components to GND in such a way that the interconnection does not have impedance in

common with other GND patterns. In addition, please carry out the pattern design in such ways as keeps such steep pulses

as square wave etc. away and that there is no noise plunging. Please mount the two components of C and R if being used

by PWM constant current control because normal PWM constant current control becomes impossible if CR terminal is open

or it is biased externally.

○MTH／Current decay mode-setting terminal

This is the terminal to set the current decay mode. Current decay mode can be optionally set according to input voltage.

MTH terminal input voltage[V]

Current decay mode

0~0.3

0.4~1.0

1.5~3.5

SLOW DECAY

MIX DECAY

FAST DECAY

Please connect to GND if using at SLOW DECAY mode.

Please avoid using with MTH terminal open because if MTH terminal is open, the input is unsettled, and then there is the

danger that PWM operation becomes unstable. Besides, please take into consideration the outflow current (max.2μA) if

inputted by resistance division when selecting the resistance value.

○NC terminal

This terminal is unconnected electrically with IC internal circuit.

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○Thermal Shutdown (TSD)

This IC has a built-in thermal shutdown circuit for thermal protection. When the IC’s chip temperature rises above

175℃(Typ.), the motor output becomes OPEN. Also, when the temperature returns to under 150℃ (Typ.), it

automatically returns to normal operation. However, even when TSD is in operation, if heat is continued to be added

externally, heat overdrive can lead to destruction.

○Over Current Protection (OCP)

This IC has a built in over current protection circuit as a provision against destruction when the motor outputs are

shorted each other or VCC-motor output or motor output-GND is shorted. This circuit latches the motor output to OPEN

condition when the regulated threshold current flows for 4μs (Typ.). It returns with power reactivation or a reset of the

PS terminal. The over current protection circuit’s only aim is to prevent the destruction of the IC from irregular situations

such as motor output shorts, and is not meant to be used as protection or security for the set. Therefore, sets should

not be designed to take into account this circuit’s functions. After OCP operating, if irregular situations continues and

the return by power reactivation or a reset of the PS terminal is carried out repeatedly, then OCP operates repeatedly

and the IC may generate heat or otherwise deteriorate. When the L value of the wiring is great due to the wiring being

long, after the over current has flowed and the output terminal voltage jumps up and the absolute maximum values

may be exceeded and as a result, there is a possibility of destruction. Also, when current which is over the output

current rating and under the OCP detection current flows, the IC can heat up to over Tjmax=150℃ and can deteriorate,

so current which exceeds the output rating should not be applied.

○Under Voltage Lock Out (UVLO)

This IC has a built-in under voltage lock out function to prevent false operation such as IC output during power supply

under voltage. When the applied voltage to the VCC terminal goes under 15V (Typ.), the motor output is set to OPEN.

This switching voltage has a 1V (Typ.) hysteresis to prevent false operation by noise etc. Please be aware that this

circuit does not operate during power save mode. Also, the electrical angle is reset when the UVLO circuit operates

during PARA-IN drive mode.

○Over Voltage Lock Out (OVLO)

This IC has a built-in over voltage lock out function to protect the IC output and the motor during power supply over

voltage. When the applied voltage to the VCC terminal goes over 32V (Typ.), the motor output is set to OPEN. This

switching voltage has a 1V (Typ.) hysteresis and a 4μs (Typ.) mask time to prevent false operation by noise etc.

Although this over voltage locked out circuit is built-in, there is a possibility of destruction if the absolute maximum

value for power supply voltage is exceeded, therefore the absolute maximum value should not be exceeded. Please be

aware that this circuit does not operate during power save mode.

○Ghost Supply Prevention (protects against malfunction when power supply is disconnected)

If a signal (logic input, MTH, VREF) is input when there is no power supplied to this IC, there is a function which

prevents the false operation by voltage supplied via the electrostatic destruction prevention diode from these input

terminals to the VCC to this IC or to another IC’s power supply. Therefore, there is no malfunction of the circuit even

when voltage is supplied to these input terminals while there is no power supply.

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○PWM Constant current control

1) Current control operation

When the output transistor is turned on, the output current increases, raising the voltage over the current sense resistor.

When the voltage on the RNF pin reaches the voltage value set by the internal 2-bit DAC and the VREF input voltage, the

current limit comparator engages and enters current decay mode. The output is then held off for a period of time

determined by the RC time constant connected to the CR pin. The process repeats itself constantly for PWM operation.

2) Noise-masking function

In order to avoid misdetection of output current due to RNF spikes that may occur when the output turns ON, the IC

employs an automatic current detection-masking period (t^ONMIN), during which current detection is disabled immediately

after the output transistor is turned on. This allows for constant-current drive without the need for an external filter. This

noise-masking period defines the minimum ON-time for the motor output transistor.

3) CR Timer

The CR filter connected to the CR pin is repeatedly charged and discharged between the VCRH and VCRL levels. The

output of the internal comparator is masked while charging from VCRL to VCRH in order to cancel noise. (As mentioned

above, this period defines the minimum ON-time of the motor output transistor.) The CR terminal begins discharging once

the voltage reaches VCRH. When the output current reaches the current limit during this period (i.e. RNF voltage reaches

the decay trigger voltage), then the IC enters decay mode. The CR continues to discharge during this period until it reaches

VCRL, at which point the IC output is switched back ON. The current output and CR pin begin charging simultaneously.

The CR charge time (t^ONMIN) and discharge time (tdischarge) are set by external components, according to the following

formulas. The total of t^ONMINand tdischarge yield the chopping period, tchop.

t^ONMIN[s]≒C･R'･R / (R'+R)･ln[(VCR-0.4)/(VCR-1.0)]

VCR=V･R/(R'+R)

V: internal regulator voltage 5V(Typ.)

R': CR terminal internal impedance 5kΩ(Typ.)

0.30

0.25

0.20

0.15

0.10

0.05

0.00

t^discharge[s]≒C･R･ln[(1+α)/0.4]

α:See the right graph.

t^CHOP[s]≒tONMIN + tdischarge

0

500

1000

Cꢀ[pF]

1500

2000

Spike noise

Current limit Value

0mA

Output current

RNF Voltage

Current limit Value

GND

VCRH(1.0V typ.)

CR Voltage

VCRL(0.4V typ.)

GND

Discharge time

t_discharge

Chopping Period

t_CHOP

Minimum ON Time

t_ONMIN

Figure 4 Timing chart of CR voltage, RNF voltage and output current

Attach a resistor of at least 10 kΩ to the CR terminal (10 kΩ~200 kΩ recommended) as lower values may keep the RC from

reaching the VCRH voltage level. A capacitor in the range of 470 pF – 1500 pF is also recommended. As the capacitance

value is increased, however, the noise-masking period (t^onmin) also increases, and there is a risk that the output current may

exceed the current limit threshold due to the internal L and R components of the output motor coil. Also, ensure that the

chopping period (tchop) is not set longer than necessary, as doing so will increase the output ripple, thereby decreasing the

average output current and yielding lower output rotation efficiency. The optimal value should reduce the motor drive noise

while keeping distortion of the output current waveform to a minimum.

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○Current decay mode

The IC allows for a mixed decay mode in which the ratio of fast and slow decay can be optionally set.

The following diagrams show the operating state of each transistor and the regenerative current path during attenuation for

each decay mode:

SLOW DECAY

FAST DECAY

OFF→OFF

OFF

ON→OFF

M

OFF→ON

ON→ON

ON→OFF

Output ON Time

Current Decay Time

Figure 5 Route of Regenerated Current during Current Decay

The merits of each decay mode are as follows:

○SLOW DECAY

During current attenuation, the voltage between motor coils is small and the regeneration current decreases slowly,

decreasing the output current ripple. This is favorable for keeping motor torque high. However, due to fall-off of current

control characteristics in the low-current region, or due to reverse EMF of the output motors exhibited when using

high-pulse-rate half-step or quarter-step modes, the output current increases, distorting the output current waveform and

increasing motor vibration. Thus, this decay mode is most suited to full-step modes, or low-pulse-rate half-step or

quarter-step modes.

○FAST DECAY

Fast decay decreases the regeneration current much more quickly than slow decay, greatly reducing distortion of the

output current waveform. However, fast decay yields a much larger output current ripple, which decreases the overall

average current running through the motor. This causes two problems: first, the motor torque decreases (increasing the

current limit value can help eliminate this problem, but the rated output current must be taken into consideration); and

second, the power loss within the motor increases and thereby radiates more heat. If neither of these problems is of

concern, then fast decay can be used for high-pulse rate half- or quarter-step drive.

Additionally, this IC allows for a mixed decay mode that can help improve upon problems that arise from using fast or slow

decay alone. In this mode, the IC switches automatically between slow and fast decay, improving the current control

characteristics without increasing the output current ripple. The ratio of fast to slow decay is set externally via the voltage

input to the MTH pin; therefore, the optimal mix of slow and fast decay can be achieved for each application. Mixed decay

mode operates by splitting the decay period into two sections, the first X%(t1-t2) of which operates the IC in slow decay

mode, and the remainder(t2-t3) of which operates in fast decay mode. However, if the output current (i.e., the voltage on

the RNF pin) does not reach the set current limit during the first X% (t1-t2) decay period, the IC operates in fast decay

mode only.

MTH voltage [V]

Current decay mode

0~0.3

0.4~1.0

1.5~3.5

SLOW DECAY

MIX DECAY

FAST DECAY

t1

t2

t3

1.0V

CR Voltage

MTH Voltage

0.4V

GND

Chopping Period

t_chop

Current limit value

Output Current

FAST

SLOW

DECAY

0A

Figure 6 Relation between CR terminal voltage, MTH voltage, and output current during mixed decay

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BD68720EFV

●PARALLEL-IN drive mode

It is possible to drive stepping motor with FULL STEP, HALF STEP, and QUARTER STEP by inputting the following motor

control signals using PARALLEL-IN drive mode.

Examples of control sequence and torque vector

FULL STEP

Controlled by 2 logic signals of PHASE1 & PHASE2

①

②

③

④

OUT1A

100%

67%

PHASE1

PHASE2

I01

4

3

1

2

33%

I11

OUT2A

OUT2B

I02

I12

100%

67%

33%

IOUT(CH1)

IOUT(CH2)

OUT1B

-33%

-67%

-100%

100%

67%

33%

-33%

-67%

-100%

HALF STEP A

Controlled by 4 logic signals of PHASE1,PHASE2, I01(I11), and I02(I12)

①

②

③

④

⑤

⑥

⑦

⑧

OUT1A

1

100%

67%

PHASE1

PHASE2

I01

2

4

8

6

33%

I11

OUT2B

OUT2A

7

3

I02

I12

100%

67%

33%

5

IOUT(CH1)

IOUT(CH2)

OUT1B

-33%

-67%

-100%

100%

67%

33%

-33%

-67%

-100%

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BD68720EFV

HALF STEP B

Controlled by 6 logic signals of PHASE1,PHASE2, I01,I11,I02, and I12

①

②

③

④

⑤

⑥

⑦

⑧

OUT1A

1

100%

67%

PHASE1

PHASE2

I01

2

4

33%

8

6

I11

OUT2B

OUT2A

7

3

I02

I12

100%

67%

33%

5

IOUT(CH1)

IOUT(CH2)

OUT1B

-33%

-67%

-100%

100%

67%

33%

-33%

-67%

-100%

QUARTER STEP

Controlled by 6 logic signals of PHASE1,PHASE2, I01,I11,I02, and I12

① ② ③ ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩ ⑪ ⑫ ⑬ ⑭ ⑮ ⑯

OUT1A

100%

67%

33%

PHASE1

PHASE2

I01

1

2

16

2

15

3

7

14

4

I11

OUT2A

OUT2B

13

12

5

6

I02

I12

11

8

100%

10

9

67%

33%

IOUT(CH1)

-33%

OUT1B

-67%

-100%

100%

67%

33%

IOUT(CH2)

-33%

-67%

-100%

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BD68720EFV

●Power dissipation

Please confirm that the IC’s chip temperature Tj is not over 150℃, while considering the IC’s power consumption (W) and

ambient temperature (Ta). When Tj=150℃ is exceeded the functions as a semiconductor do not operate and problems such

as parasitism and leaks occur. Constant use under these circumstances leads to deterioration and eventually destruction of

the IC. Tjmax=150℃ must be strictly obeyed under all circumstances.

○Thermal Calculation

The IC’s consumed power can be estimated roughly with the power supply voltage (V^CC), circuit current (ICC), output ON

resistance (RONH､RONL) and motor output current value (IOUT).

The calculation method during FULL STEP drive, SLOW DECAY mode is shown here:

Consumed power of the Vcc [W] = V^CC[V]･ICC [A] ･･･････①

Consumed power of the output DMOS [W] = (RONH[Ω] + RONL[Ω])･IOUT [A]2･2[ch]･on_duty

During output ON

+ (2･RONL[Ω])･IOUT [A]2･2[ch]･(1 - on_duty) ･･･････②

During current decay

However, on duty: PWM on duty = t^on/ (tchop)

t^onvaries depending on the L and R values of the motor coil and the current set value. Please confirm by actual

measurement, or make an approximate calculation.

tchop is the chopping period, which depends on the external CR. See P.8 for details.

Upper PchDMOS ON Resistance

Lower NchDMOS ON Resistance

IC number

BD68720EFV

R^ONH[Ω] (Typ.)

RONL[Ω] (Typ.)

0.40

0.25

Consumed power of total IC W_total [W] = ① + ②

Junction temperature Tj = Ta[℃] + θja[℃/W]･W_total [W]

However, the thermal resistance valueθ^ja[℃/W] differs greatly depending on circuit board conditions. Refer to the

derating curve on P.17.Also, we are taking measurements of thermal resistance valueθja of boards actually in use.

Please feel free to contact our salesman. The calculated values above are only theoretical. For actual thermal design,

please perform sufficient thermal evaluation for the application board used, and create the thermal design with enough

margin to not exceed Tjmax=150℃.Although unnecessary with normal use, if the IC is to be used under especially

strict heat conditions, please consider externally attaching a Schottky diode between the motor output terminal and

GND to abate heat from the IC.

○Temperature Monitoring

In respect of BD68720EFV, there is a way to approximately measure the chip temperature by using the electrostatic discharge

protection diode of the logic terminal (I0x or I1x) can be used when at L state. Temperature monitoring using this method is

only for evaluation and experimenting purposes, and must not be used in actual usage conditions.

(1)Measure the terminal voltage when a current of I_DIODE=50µA passes from the I0x or I1x terminal to the GND

without supplying VCC to the IC. This measurement is the V_fvoltage of the internal diode.

(2)Measure the temperature characteristics of this terminal voltage. V_fhas a linear negative temperature factor

against temperature. With these results of temperature characteristics, chip temperature may be calibrated from the

I0x or I1x terminal voltage.

(3)Supply VCC, monitor the I0x or I1x terminal voltage while running the motor, and the chip temperature can be

approximated from the results of (2).

-Vf[mV]

I0x or I1x

Internal circuit

Idiode

Vf

25

150

Chip temperature T_j[℃]

Figure.7 Model diagram for measuring chip temperature

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BD68720EFV

●Example for applied circuit

Power save terminal

Refer to P.6 for detail.

Logic input terminal

See P6 for detail.

15

17

16

18

PHASE1

TSD

OCP

PHASE2

I01

GND

PS

9

OVLO

UVLO

Translator

I11

RESET

I02 19

20

14

I12

Bypass capacitor.

Setting range is

＋

－

VREF 13

100uF～470uF(electrolytic)

0.01uF～0.1uF(multilayer ceramic

etc.)

2bit DAC

Set the output current.

Input by resistor division.

Refer to P.6 for detail.

Be sure to short VCC1 & VCC2.

VCC1

7

OUT1A

＋

－

5

2

RNF1S

RNF2S

Set the chopping

frequency.

OUT1B

RNF1

3

4

Setting range is

＋

－

0.2Ω

C:470pF～1500pF

R:10kΩ～200kΩ

Refer to P.7, 9 for detail.

100µF

0.1µF

RNF1S

VCC2

Blank time

PWM control

22

OUT2A

CR

10

24

27

Resistor for current detection

Setting range is

0.1Ω～0.3Ω.

OSC

OUT2B

RNF2

39kΩ

1000pF

26

25

Mix decay

control

Refer to P.7 for detail.

0.2Ω

MTH 12

Set the current decay mode.

①SLOW DECAY

⇒Connect to GND.

RNF2S

GND

Regulator

1

②MIX DECAY

⇒Input by resistor division.

Refer to P.7, 10 for detail.

Resistor for current detection

Setting range is

0.1Ω～0.3Ω.

Refer to P.7 for detail.

Figure.8 Block diagram and applied circuit diagram

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BD68720EFV

●Input output equivalent circuit diagram

PS

I01

I11

I02

I12

PHASE1

PHASE2

VREF

MTH

10kΩ

5kΩ

215kΩ

100kΩ

10kΩ

100kΩ

VREG (internal regulator)

RNF1S

RNF2S

5kΩ

CR

5kΩ

VCC

OUT1A

OUT2A

OUT1B

OUT2B

RNF1, RNF2

circuitry

Figure.9 Input output equivalent circuit diagram

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BD68720EFV

Operational Notes

1. Reverse Connection of Power Supply

Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when

connecting the power supply, such as mounting an external diode between the power supply and the IC’s power

supply pins.

2. Power Supply Lines

Design the PCB layout pattern to provide low impedance supply lines. Separate the ground and supply lines of the

digital and analog blocks to prevent noise in the ground and supply lines of the digital block from affecting the analog

block. Furthermore, connect a capacitor to ground at all power supply pins. Consider the effect of temperature and

aging on the capacitance value when using electrolytic capacitors.

3. Ground Voltage

Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition.

4. Ground Wiring Pattern

When using both small-signal and large-current ground traces, the two ground traces should be routed separately but

connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal

ground caused by large currents. Also ensure that the ground traces of external components do not cause variations

on the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance.

5. Thermal Consideration

Should by any chance the maximum junction temperature rating be exceeded the rise in temperature of the chip may

result in deterioration of the properties of the chip. In case of exceeding this absolute maximum rating, increase the

board size and copper area to prevent exceeding the maximum junction temperature rating.

6. Recommended Operating Conditions

These conditions represent a range within which the expected characteristics of the IC can be approximately

obtained. The electrical characteristics are guaranteed under the conditions of each parameter.

7. Inrush Current

When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush

current may flow instantaneously due to the internal powering sequence and delays, especially if the IC

has more than one power supply. Therefore, give special consideration to power coupling capacitance,

power wiring, width of ground wiring, and routing of connections.

8. Operation Under Strong Electromagnetic Field

Operating the IC in the presence of a strong electromagnetic field may cause the IC to malfunction.

9. Testing on Application Boards

When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may

subject the IC to stress. Always discharge capacitors completely after each process or step. The IC’s power supply

should always be turned off completely before connecting or removing it from the test setup during the inspection

process. To prevent damage from static discharge, ground the IC during assembly and use similar precautions during

transport and storage.

10. Inter-pin Short and Mounting Errors

Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in

damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin.

Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment)

and unintentional solder bridge deposited in between pins during assembly to name a few.

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BD68720EFV

Operational Notes – continued

11. Unused Input Pins

Input pins of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance and

extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small

charge acquired in this way is enough to produce a significant effect on the conduction through the transistor and

cause unexpected operation of the IC. So unless otherwise specified, unused input pins should be connected to the

power supply or ground line.

12. Regarding the Input Pin of the IC

This monolithic IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them

isolated. P-N junctions are formed at the intersection of the P layers with the N layers of other elements, creating a

parasitic diode or transistor. For example (refer to figure below):

When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.

When GND > Pin B, the P-N junction operates as a parasitic transistor.

Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual

interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to

operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should

be avoided.

Figure 10. Example of monolithic IC structure

13. Thermal Shutdown Circuit(TSD)

This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always

be within the IC’s power dissipation rating. If however the rating is exceeded for a continued period, the junction

temperature (Tj) will rise which will activate the TSD circuit that will turn OFF all output pins. When the Tj falls below

the TSD threshold, the circuits are automatically restored to normal operation.

Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no

circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from

heat damage.

14. Over Current Protection Circuit (OCP)

This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This

protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should

not be used in applications characterized by continuous operation or transitioning of the protection circuit.

15. Operation Under Strong Electromagnetic Field (BD68720EFV)

The IC is not designed for using in the presence of strong electromagnetic field. Be sure to confirm that no

malfunction is found when using the IC in a strong electromagnetic field.

16. Metal on the backside (Define the side where product markings are printed as front) (BD68720EFV)

The metal on the backside is shorted with the backside of IC chip therefore it should be connected to GND. Be aware

that here is a possibility of malfunction or destruction if it is shorted with any potential other than GND.

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BD68720EFV

●

Selecting a model name when ordering

E F V

B D 6 8 7 2 0

-

E 2

Package type

EFV :HTSSOP-B28

Packing, Forming specification

E2: Reel-wound embossed taping

ROHM Model

● Marking Diagram

HTSSOP-B28 (TOP VIEW)

Part Number Marking

LOT Number

B D 6 8 7 2 0 E F V

1PIN MARK

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BD68720EFV

Physical Dimension, Tape and Reel Information

Package Name

HTSSOP-B28

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BD68720EFV

Revision History

Date

Revision

001

Changes

10.Jun.2016

New Release

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TSZ22111・15・001

Notice

Precaution on using ROHM Products

1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,

OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you

intend to use our Products in devices requiring extremely high reliability (such as medical equipment ^{(Note 1)}, transport

equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car

accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or

serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.

Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any

damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific

Applications.

(Note1) Medical Equipment Classification of the Specific Applications

JAPAN

USA

EU

CHINA

CLASSⅢ

CLASSⅣ

CLASSⅡb

CLASSⅢ

2. ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor

products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate

safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which

a failure or malfunction of our Products may cause. The following are examples of safety measures:

[a] Installation of protection circuits or other protective devices to improve system safety

[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure

3. Our Products are designed and manufactured for use under standard conditions and not under any special or

extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way

responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any

special or extraordinary environments or conditions. If you intend to use our Products under any special or

extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of

product performance, reliability, etc, prior to use, must be necessary:

[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents

[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust

[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,

H2S, NH3, SO2, and NO2

[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves

[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items

[f] Sealing or coating our Products with resin or other coating materials

[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of

flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning

residue after soldering

[h] Use of the Products in places subject to dew condensation

4. The Products are not subject to radiation-proof design.

5. Please verify and confirm characteristics of the final or mounted products in using the Products.

6. In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,

confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power

exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect

product performance and reliability.

7. De-rate Power Dissipation depending on ambient temperature. When used in sealed area, confirm that it is the use in

the range that does not exceed the maximum junction temperature.

8. Confirm that operation temperature is within the specified range described in the product specification.

9. ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in

this document.

Precaution for Mounting / Circuit board design

1. When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product

performance and reliability.

2. In principle, the reflow soldering method must be used on a surface-mount products, the flow soldering method must

be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products,

please consult with the ROHM representative in advance.

For details, please refer to ROHM Mounting specification

Notice-PGA-E

Rev.003

Precautions Regarding Application Examples and External Circuits

1. If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the

characteristics of the Products and external components, including transient characteristics, as well as static

characteristics.

2. You agree that application notes, reference designs, and associated data and information contained in this document

are presented only as guidance for Products use. Therefore, in case you use such information, you are solely

responsible for it and you must exercise your own independent verification and judgment in the use of such information

contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses

incurred by you or third parties arising from the use of such information.

Precaution for Electrostatic

This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper

caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be

applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,

isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).

Precaution for Storage / Transportation

1. Product performance and soldered connections may deteriorate if the Products are stored in the places where:

[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2

[b] the temperature or humidity exceeds those recommended by ROHM

[c] the Products are exposed to direct sunshine or condensation

[d] the Products are exposed to high Electrostatic

2. Even under ROHM recommended storage condition, solderability of products out of recommended storage time period

may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is

exceeding the recommended storage time period.

3. Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads

may occur due to excessive stress applied when dropping of a carton.

4. Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of

which storage time is exceeding the recommended storage time period.

Precaution for Product Label

A two-dimensional barcode printed on ROHM Products label is for ROHM’s internal use only.

Precaution for Disposition

When disposing Products please dispose them properly using an authorized industry waste company.

Precaution for Foreign Exchange and Foreign Trade act

Since concerned goods might be fallen under listed items of export control prescribed by Foreign exchange and Foreign

trade act, please consult with ROHM in case of export.

Precaution Regarding Intellectual Property Rights

1. All information and data including but not limited to application example contained in this document is for reference

only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any

other rights of any third party regarding such information or data.

2. ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the

Products with other articles such as components, circuits, systems or external equipment (including software).

3. No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any

third parties with respect to the Products or the information contained in this document. Provided, however, that ROHM

will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to

manufacture or sell products containing the Products, subject to the terms and conditions herein.

Other Precaution

1. This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.

2. The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written

consent of ROHM.

3. In no event shall you use in any way whatsoever the Products and the related technical information contained in the

Products or this document for any military purposes, including but not limited to, the development of mass-destruction

weapons.

4. The proper names of companies or products described in this document are trademarks or registered trademarks of

ROHM, its affiliated companies or third parties.

Notice-PGA-E

Rev.003


型号：	BD68720EFV
厂家：	ROHM
描述：	BD68720EFV是额定电源36V､额定输出电流2.0A的低功耗双极PWM恒流驱动器。输入接口采用PARA-IN驱动方式，对于电流衰减方式，可自由设定FAST DECAY/SLOW DECAY的比率，可对所有电机实现很好的控制状态。另外，也可使用一个系统电源进行驱动，因此有助于提高整机设计的便利性。电机驱动驱动器
文件：	总23页 (文件大小：2021K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

BD68720EFV [ROHM]

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