BD68888AEKV_技术文档

Datasheet

36V

2ch Stepping Motor Driver

BD68888AEKV

General Description

Key Specifications

BD68888AEKV is a bipolar low-consumption driver that

driven by PWM constant current. Rated power supply

voltage of the device is 36 V, and rated output current is

1.5 A. PARA-IN drive mode is adopted for input interface.

This motor driver can drive 2ch bipolar stepping motors.

In addition, the power supply can be driven by one single

system, which simplifies the design.

■

Range of Power Supply Voltage

Rated Output Current

Range of Operating Temperature -25 °C to +85 °C

8 V to 28 V

1.5 A

Output ON Resistance

1.0 Ω (Typ)

(total of upper and lower resistors)

Package

HTQFP48V

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

9.00 mm x 9.00 mm x 1.00 mm

Features

■

Two bipolar stepping motors can be driven

Rated Output Current 1.5 A

Low ON Resistance DMOS Output

PARA-IN Drive Mode correspondence

PWM Constant Current control (the other excitation

method)

■

Built-in Spike Noise Blanking Function (external noise

filter is unnecessary)

■

Full-, Half (two kinds)-, Quarter-step correspondence

Power Save Function

Built-in Logic Input Pull-down Resistor

Thermal Shutdown Circuit (TSD)

Over-current Protection Circuit (OCP)

Under Voltage Lockout Circuit (UVLO)

Over Voltage Lockout Circuit (OVLO)

Ghost Supply Prevention (protects against

malfunction when power supply is disconnected)

Typical Application Circuit

OUT1A

PHASE1

PHASE2

I01

OUT1B

I11

I02

I12

SENSE1

Application

Monitoring

■

Camera,

WEB

Camera,

PPC,

VBB1

Multi-function Printer, Laser Beam Printer, Ink-jet

Printer, Sewing Machine, Photo Printer, FAX,

Scanner, Mini Printer, Toy and Robot

OUT2A

OUT2B

VREF1

VREF2

VREF3

VREF4

SENSE2

OUT3A

OUT3B

SENSE3

PHASE3

PHASE4

I03

VBB2

OUT4A

I13

I04

I14

OUT4B

SENSE4

PS

GND

Figure 1. BD68888AEKV Application Circuit Diagram

○Product structure : Silicon monolithic integrated circuit ○This product has no designed protection against radioactive rays

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Pin Configuration

Block Diagram

[TOP VIEW]

Regulator

PHASE1

PHASE2

I01

I11

I02

I12

RESET

UVLO

OVLO

TSD

Interface

OCP

VREF1

VREF2

36 35 34 33 32 31 30 29 28 27 26 25

2bit DAC

VBB1

SENSE1

I13 37

I12 38

I11 39

24 I14

OUT1A

OUT1B

SENSE2

23 NC

Blank time

PWM control

SENSE1

Control

logic

Pre-

driver

22 PHASE1

VBB1

PHASE2

21

40

GND

OSC

OUT2A

OUT2B

NC 41

NC 42

20 GND

Mix decay

control

19 VREF4

18 VREF3

SENSE2

43

44

TEST1

TEST2

VREF3

VREF4

2bit DAC

VREF2

17

VBB2

SENSE3

I01 45

I02 46

16 VREF1

EXP-PAD

OUT3A

OUT3B

SENSE4

PS

15

14

13

Blank time

PWM control

SENSE3

I03

I04

PHASE3

PHASE4

47

48

Control

logic

Pre-

driver

VBB2

OSC

OUT4A

OUT4B

1

2

3

4

5

6

7

8

9 10 11 12

Mix decay

control

SENSE4

PHASE3

PHASE4

I03

Interface

I13

GND

I04

I14

PS

Figure 2. Pins Configuration Diagram

Figure 3. BD68888AEKV Block Diagram

Pin Descriptions

No.

Pin Name

No.

Function

Non connection

Pin name

Function

Non connection

NC

1

2

3

25

26

27

Non connection

OUT1A

H bridge output pin

OUT4A

H bridge output pin

Connection pin of resistor for output

current detection

Connection pin of resistor for output

current detection

SENSE1

SENSE4

4

28

5

6

7

8

OUT1B

VBB1

NC

H bridge output pin

Power supply pin

Non connection

29

30

31

32

OUT4B

NC

H bridge output pin

Non connection

VBB2

Power supply pin

OUT2B

H bridge output pin

OUT3B

H bridge output pin

Connection pin of resistor for output

current detection

Connection pin of resistor for output

current detection

SENSE2

SENSE3

9

33

10

11

12

13

14

15

16

OUT2A

NC

H bridge output pin

34

35

36

37

38

39

40

OUT3A

NC

H bridge output pin

Non connection

NC

Non connection

PHASE4

PHASE3

PS

Phase selection pin

Power save pin

I13

I12

VREF division ratio setting pin

Ground pin

I11

VREF1

Output current value setting pin

GND

NC

17

VREF2

Output current value setting pin

41

Non connection

NC

TEST1

TEST2

I01

18

19

20

21

22

23

24

VREF3

VREF4

GND

Output current value setting pin

Ground pin

42

43

44

45

46

47

48

Non connection

Pin for testing

PHASE2

PHASE1

NC

Phase selection pin

VREF division ratio setting pin

Phase selection pin

I02

Non connection

I03

I14

VREF division ratio setting pin

I04

The EXP-PAD of the center of

product connect to GND.

-

EXP-PAD

-

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Absolute Maximum Ratings (Ta=25 °C)

Item

Symbol

Rated Value

-0.2 to +36.0

-0.2 to +5.5

0.7

Unit

Supply Voltage

VBB1,VBB2

V_IN

V

Input Voltage for Control Pin

SENSE Maximum Input Voltage

Output Current^{(Note 2)}

V

V_SENSE

I_OUT

1.5^{(Note 1)}

-55 to +150

+150

A/Phase

°C

Storage Temperature Range

Maximum Junction Temperature

Tstg

Tjmax

°C

Caution 1: 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.

Caution 2: 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, design a PCB boards with thermal resistance taken into consideration by

increasing board size and copper area so as not to exceed the maximum junction temperature rating.

(Note 1) Do not exceed Tjmax=150 °C.

Recommended Operating Conditions

Item

Symbol

Min

-25

+8

-

Typ

+25

+24

-

Max

+85

Unit

°C

Operating Temperature

Supply Voltage

Topr

VBB1,VBB2

I_OUT

+28

V

Maximum Output

Current (DC)

+1.2^{(Note 2)}

A/ Phase

(Note 2) Do not exceed Tjmax=150 °C.

Thermal Resistance^{(Note 3)}

Thermal Resistance (Typ)

Parameter

Symbol

Unit

1s^{(Note 5)}

2s2p^{(Note 6)}

HTQFP48V

Junction to Ambient

Junction to Top Characterization Parameter^{(Note 4)}

θ_JA

82.6

3

21.4

2

°C/W

Ψ_JT

(Note 3) Based on JESD51-2A (Still-Air).

(Note 4) 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 5) Using a PCB board based on JESD51-3.

(Note 6) Using a PCB board based on JESD51-5, 7.

Layer Number of

Measurement Board

Material

FR-4

Board Size

Single

114.3 mm x 76.2 mm x 1.57 mmt

Top

Copper Pattern

Thickness

Footprints and Traces

70 μm

Thermal Via^{(Note 7)}

Layer Number of

Measurement Board

Material

FR-4

Board Size

114.3 mm x 76.2 mm x 1.6 mmt

2 Internal Layers

Pitch

Diameter

4 Layers

1.20 mm

Φ0.30 mm

Top

Copper Pattern

Bottom

Thickness

Copper Pattern

Thickness

Copper Pattern

Thickness

Footprints and Traces

70 μm

74.2 mm x 74.2 mm

35 μm

74.2 mm x 74.2 mm

70 μm

(Note 7) This thermal via connects with the copper pattern of all layers.

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Electrical Characteristics (Unless otherwise specified Ta=25 °C, VBB1, VBB2=24 V)

Limit

Item

Symbol

Unit

Condition

Min

Typ

Max

[Whole]

Circuit Current at Standby

I_CCST

I_CC

-

0

10

µA

PS=L

Circuit Current

[Control Input]

5.0

8.0

mA

PS=H, VREFx^{(Note 8)}=1.5 V

H-level Input Voltage

L-level Input Voltage

H-level Input Current

L-level Input Current

[Output]

V_INH

V_INL

I_INH

I_INL

2.0

-

V

0.8

100

-

35

-10

50

0

µA

V_IN=5 V

V_IN=0 V

I_OUT=±1.0 A

Output ON Resistance

R_ON

-

1.0

-

1.4

10

Ω

(total of upper and lower)

Output Leak Current

[Current Control]

I_LEAK

µA

SENSEx^{(Note 9)}Input Current

VREFx Input Current

I_SENSE

I_VREF

-80

-2.0

0

-40

-0.1

-

µA

V

SENSEx=0 V

VREFx=0 V

VREFx Input Voltage Range

V_VREF

1.5

Minimum ON Time

(Blank Time)

t_ONMIN

V_CTH

0.3

1.0

1.5

µs

V

Comparator Threshold

0.48

0.50

0.52

VREFx=1.5 V

(Note 8) x=1,2,3 or 4

(Note 9) x=1,2,3 or 4

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Function Explanation

PS/Power Save Pin

The PS pin can make the circuit standby state and make the motor output OPEN. When PS=L→H, be careful because there

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

PS

Status

Standby state

ACTIVE

L

H

PHASEx ^{(Note 10)}/Phase Selection Pin

These pins determine output state.

PHASEx

OUTxA^{(Note 11)}

OUTxB^{(Note 12)}

L

H

L

H

(Note 10) x=1, 2, 3 or 4

(Note 11) x=1, 2, 3 or 4

(Note 12) x=1, 2, 3 or 4

I0x ^{(Note 13)},I1x^{(Note 14)}/VREF Division Ratio Setting Pin

Although VREF pins voltage is input to 2bit-DAC, these pins set the split ratio of 2bit-DAC output voltage.

I0x

L

I1x

L

Output Current Level (%)

100

67

33

0

H

L

H

(I0x, I1x)=(H, H): motor outputs are open.

(Note 13) x=1, 2, 3 or 4

(Note 14) x=1, 2, 3 or 4

VBB1, VBB2/Power Supply Pin

The wire should be thick, short and has low impedance, because Motor’s drive current is flowing in it. The VBB1 pin and the

VBB2 pin voltage may have great fluctuation, so arrange the bypass capacitor of about 100 µF to 470 µF as close to the pin

as possible and adjust the VBB1 pin and the VBB2 pin voltage is stable. Increase the capacity as 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 wideband, it is recommended to set parallel

connection of multi-layered ceramic capacitor of 0.01 µF to 0.1 µF etc. Extreme care must be used to make sure that the

VBB1 pin and the VBB2 pin voltage do not exceed the rating even for a moment. The VBB1 pin and the VBB2 pin are

shorted inside the IC, but be sure to short externally the VBB1 pin and the VBB2 pin when using. If used without shorting,

malfunction or destruction may occur because of concentration of current routes etc. Still more, in the power supply pin,

there is built-in clamp component for preventing of electrostatic destruction. When a steep pulse signal or voltage such as a

surge exceeding the absolute maximum rating is applied, this clamp component operates, and the IC might be destroyed as

a result. 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 electrostatic destruction is inserted between the VBB1 pin, the

VBB2 pin and the GND pin. Be careful about the reverse voltage because the IC might be destroyed as a result if reverse

voltage is applied to the VBB1 pin, the VBB2 pin and the GND pin.

GND/Ground Pin

In order to reduce the electric noise by switching current and to stabilize the internal reference voltage of the IC, make the

wiring impedance from this pin as low as possible to achieve the lowest electrical potential no matter what operating state it

can be. Moreover, design the patterns not to have any common impedance with other GND patterns.

OUTxA, OUTxB/H Bridge Output Pin

Motor’s drive current is flowing in it, so the wire should be 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. For example, counter

electromotive voltage etc. Moreover, in the output pin, there is built-in clamp component for preventing of electrostatic

destruction. When a steep pulse signal or voltage such as a surge exceeding the absolute maximum rating is applied, this

clamp component operates, and the IC might be destroyed in the end. Be sure that the maximum absolute rating must not

exceeded.

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Function Explanation – continued

SENSEx^{(Note 15)}/Connection Pin of Resistor for Detecting of Output Current

Connect the resistor of 0.1 Ω to 0.3 Ω for current detection between this pin and GND. Determine the resistor so that power

consumption W=I_OUT²•R [W] of the current-detecting resistor does not exceed the maximum absolute rating of the resistor. In

addition, it has a low impedance and does not have a common impedance with other GND patterns because motor’s drive

current flows in the pattern through the SENSE_Xpin to current-detecting resistor to GND. Do not exceed the rating because

there is the possibility of circuits’ malfunction etc., if the SENSE pin voltage exceeds the maximum rating (0.7V). Moreover,

be careful because if the SENSEx pin is shorted to GND, large current flows without normal PWM constant current control,

and OCP or TSD might operate. If there is a possibility of malfunction, such as output does not flow even when the SENSEx

pin is open, please do not put to such a state.

(Note 15) x=1, 2, 3 or 4

VREFx^{(Note 16)}/Output Current Value Setting Pin

This is the pin to set the output current value. It can be set by the VREF pin voltage and current-detecting resistor (SENSE

resistor).

퐼_푂푈푇

Where

=

^푉푅퐸퐹/ 푆ꢀ푁푆ꢀ

[A]

3

I_OUTis the output current.

VREF is the voltage of output current value-setting pin.

SENSE is the current-detecting resistor.

Avoid using the IC with the VREFx pin is open because if it is open, it may have malfunctions such as flowing a large current

by unstable input, the increased the VREFx pin voltage and increased setting current. The input voltage range must be kept

because a large current might flow to output and OCP or TSD might operate if the voltage of over 1.5 V is applied on the

VREFx pin. Besides, select the resistance value in consideration of the outflow current (Max 2 µA) if it is inputted by

resistance division. The minimum current, which can be controlled by the VREFx pin voltage, is determined by motor coil’s L,

R values and minimum ON time because there is a minimum ON time in PWM drive.

(Note 16) x=1, 2, 3 or 4

TESTx^{(Note 17)}/Pin for Inspection

This pin is used for delivery inspection of the IC, and shall be grounded before use.

In addition, malfunctions can be caused by application without grounding.

(Note 17) x=1 or 2

NC Pin

This pin is unconnected electrically with the IC internal circuit.

EXP-PAD

For HTQFP48V package, the heat-radiating metal is mounted on the IC’s backside. It is the precondition that making the

heat-radiating treatment when in use. Therefore, it must be connected by solder with the GND plane on the board and

ensure the sufficient heat-radiation area by taking the GND pattern as wide as possible. Moreover, the back side metal is

shorted with IC chip’s back side and becomes the GND potential, so there is the danger of malfunction and destruction if

shorted with potentials other than GND. Never design any wiring patterns other than GND through the IC’s backside.

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Protection Circuits

Thermal Shutdown (TSD)

This IC has a built-in thermal shutdown circuit for thermal protection. When the IC’s chip temperature rises to 175 °C (Typ)

or more, the motor output becomes OPEN. Also, when the temperature returns to 150 °C (Typ) or less, it automatically

returns to normal operation. However, if heat is continued to be added externally even while TSD is in operation, 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 VBB1, VBB2-motor output or motor output-GND is shorted. This circuit latches the motor output to OPEN

condition when the regulated current flows for 4 µs (Typ). It returns with power reactivation or a reset of the PS pin. 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 continue and the return by power

reactivation or a reset of the PS pin 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 of faults, ground faults and

shorting, there is a possibility of destruction after the over current has flowed and the output pin voltage jumps up and the

absolute maximum values can be exceeded. Also, when current which is the output current rating or more and the OCP

detection current or less flows, the IC can heat up to over Tjmax=150 °C 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 VBB1 pin and the VBB2 pin goes 5 V (Typ) or less, the motor output is set

to OPEN. This switching voltage has a 1 V (Typ) hysteresis to prevent malfunction due to noise etc. Be aware that this

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

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 VBB1 pin and the VBB2 pin goes 32 V (Typ) or more, the motor output is set to OPEN.

This switching voltage has a 1 V (Typ) hysteresis and a 4 µs (Typ) mask time to prevent malfunction due to 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. 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 control signal (logic input, VREFx) is input when there is no power supplied to this IC, there is a function which

prevents a malfunction where voltage is supplied to power supply of this IC or other IC in the set via the electrostatic

destruction prevention diode from these input pins to the VBB1 pin and the VBB2 pin. Therefore, there is no malfunction of

the circuit even when voltage is supplied to these input pins while there is no power supply.

Operation Under Strong Electromagnetic Field

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.

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PWM Constant Current Control

1) Current control operation

The output current increases due to the output transistor turned on. When the voltage on the SENSEx^{(Note 19)}pin, the output

current is converted voltage due to connect the external resistance to the SENSEx pin, reaches the voltage value set by the

internal 2-bit DAC and the VREFx^{(Note 20)}input voltage, the current limit comparator engages and enters current decay mode.

Thereafter the output turned on again after a period of time determined the internal timer. The process repeats itself

constantly.

(Note 19) x=1, 2, 3 or 4

(Note 20) x=1, 2, 3 or 4

2) Noise-masking function

In order to avoid misdetection of current detection comparator due to SENSEx spike noise that may occur when the output

turns on, the IC employs the minimum ON-time (tONMIN). It invalids the current detection for the minimum ON-time of 1 µs

(Typ) from the output transistor turned on. This allows constant-current drive without the need for an external filter.

3) Internal Timer

IC internal voltage repeat charging and discharging between VL to VH.

The detection of the internal comparator is masked while charging from VL to VH. This period defines the minimum ON-time

(t_ONMIN). The internal voltage begins discharging once the voltage reaches VH. When the output current reaches the current

limit during this period, then the IC enters decay mode. It reaches VL, at which point the IC internal voltage is switched back

ON. The current output and internal terminal begin charging simultaneously.

Spike Noise

Current Limit Value

Output Current

0 mA

Current Limit Value

SENSE Voltage

GND

VH

IC Internal Voltage

VL

GND

Chopping Period

t_CHOP

Minimum ON Time

t_ONMIN

Figure 4. Timing Chart of IC Internal Voltage, the SENSEx pin voltage and Output Current

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PWM Constant Current Control – continued

Current Decay Mode

PWM Constant Current Control can be optionally set the current decay mode in which the ratio of MIX DECAY and SLOW

DECAY.

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

decay mode:

SLOW DECAY

FAST DECAY

OFF

ON

OFF

ON

OFF

ON

M

OFF

ON

When Output ON

When Current Decay

Figure 5. Route of Regenerated Current during Current Decay

The merits of each decay mode are as follows:

SLOW DECAY

The voltage of motor coils is small and the regenerative current decreases slowly. So the output current ripple is small and

this is favorable for motor torque. However, it cannot follow the change of current limit value, the current waveform distorts

and the motor vibration increases in output current due to deterioration of current controllability in the low-current region

and it is easily influenced by EMF when high-pulse-rate in HALF STEP or QUARTER STEP modes. Thus, this decay

mode is most suited to FULL STEP modes or low-pulse-rate as 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 STEP or QUARTER STEP drive

Additionally, this IC has MIX DECAY as a method to remedy the problems caused by the above SLOW DECAY and FAST

DECAY. In this IC, SLOW DECAY / MIX DECAY (60 % Typ SLOW DECAY) can be selected.

Switching between SLOW DECAY and FAST DECAY during current decay can improve current control without increasing

current ripple.

t₁

t₂

t₃

1.0 V

IC Internal Voltage

Output Current

0.4 V

GND

Chopping Period

t_CHOP

Current Limit Value

SLOW

DECAY

FAST

DECAY

0 A

Figure 6. Internal Voltage and Output Current during MIX DECAY

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PARALLEL-IN Drive Mode -

Description for CH1 (CH2: same as CH1)-

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 and PHASE2

1

2

3

4

OUT1A

100%

67%

PHASE1

PHASE2

I01

4

3

1

2

33%

I11

OUT2A

OUT2B

I02

I12

100%

67%

33%

I_OUT(CH1)

OUT1B

-33%

-67%

-100%

100%

67%

33%

I_OUT(CH2)

-33%

-67%

-100%

HALF STEP A

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

OUT1A

1

2

3

4

5

6

7

8

100%

67%

PHASE1

PHASE2

I01

8

6

2

4

33%

OUT2B

OUT2A

I11

7

3

I02

I12

100%

67%

33%

5

I_OUT(CH1)

OUT1B

-33%

-67%

-100%

100%

67%

33%

I_OUT(CH2)

-33%

-67%

-100%

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PARALLEL-IN Drive Mode – continued

HALF STEP B

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

OUT1A

1

2

3

4

5

6

7

8

100%

67%

PHASE1

PHASE2

I01

2

4

33%

8

6

I11

OUT2B

OUT2A

7

3

I02

I12

100%

67%

33%

5

I_OUT(CH1)

OUT1B

-33%

-67%

-100%

100%

67%

33%

I_OUT(CH2)

-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%

67%

33%

10

9

I_OUT(CH1)

I_OUT(CH2)

-33%

-67%

OUT1B

-100%

100%

67%

33%

-33%

-67%

-100%

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BD68888AEKV

Power Dissipation

Confirm that the IC’s chip temperature Tj is not over 150 °C in consideration of the IC’s power consumption (W), thermal

resistance (°C/W) and ambient temperature (Ta). When Tj=150 °C 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 °C must be strictly obeyed under all circumstances.

Thermal Calculation

The IC’s consumed power can be estimated roughly with the power supply voltage (VBB1 and VBB2₎, circuit current (I_CC),

output ON resistance (RONH, RONL) and motor output current value (I_OUT).

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

푊_푉퐵퐵= ꢁꢂꢂ × 퐼_퐶퐶

[W]

where:

W_VBBis the consumed power of the VBB.

VBB is the power supply voltage.

I_CCis the circuit current.

푊_퐷푀푂ꢃ= 푊_푂ꢄ+ 푊_{퐷퐸퐶퐴푌}[W]

푊_푂ꢄ= ꢅ_푂ꢄ퐻+ ꢅ_푂ꢄ퐿× 퐼_푂푈푇²× ꢆ × 표푛_푑푢푡푦 [W]

(

)

2

(

)

(

)

푊_{퐷퐸퐶퐴푌}= ꢆ × ꢅ_푂ꢄ퐿× 퐼_푂푈푇× ꢆ × 1 − 표푛_푑푢푡푦 [W]

where:

W_DMOSis the consumed power of the output DMOS.

W_ONis the consumed power during output ON.

W_DECAYis the consumed power during current decay.

R_ONHis the upper P-channel DMOS ON-resistance.

R_ONLis the lower N-channel DMOS ON-resistance.

I_OUTis the motor output current value.

on_duty PWM on duty=푡_ꢇ푁 ⁄ 푡_ꢈꢉꢇ푃

“ ꢆ ” is the H bridge A and B.

t_ONvaries depending on the L and R values of the motor coil and the current set value. Confirm by actual measurement, or

make an approximate calculation.

t_CHOPis the chopping period, which is determined by the internal timer. Refer to P.8, 9 for details.

Upper Pch DMOS ON Resistance

Lower Nch DMOS ON Resistance

IC number

R_ONH[Ω] (Typ)

R_ONL[Ω] (Typ)

BD68888AEKV

0.70

0.30

푊_푡표푡푎푙 = 푊_푉퐵퐵+ 푊_퐷푀푂ꢃ[W]

ꢊ푗 = ꢊ푎 + 휃푗푎 × 푊_푡표푡푎푙 [°C]

where:

W_total is the consumed total power of IC.

Tj is the junction temperature.

Ta is the air temperature.

θja is the thermal resistance value.

However, the thermal resistance value θja [°C/W] differs greatly depending on circuit board conditions. The calculated values

above are only theoretical. For actual thermal design, perform sufficient thermal evaluation for the application board used,

and create the thermal design with enough margin not to exceed Tjmax=150 °C. Although unnecessary with normal use, if

the IC is to be used under especially strict heat conditions, consider externally attaching a Schottky diode between the motor

output pin and GND to abate heat from the IC.

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Power Dissipation – continued

○Temperature Monitoring

In respect of BD68888AEKV, there is a way to directly measure the approximate chip temperature by using the LOGIC pin

(I0x^{(Note 21}or I1x^{(Note 22)}) with a protection diode for prevention from electrostatic discharge. However, temperature monitor

using this LOGIC pin is only for evaluation and experimenting, and must not be used in actual usage conditions.

(Note 21) x=1, 2, 3 or 4

(Note 22) x=1, 2, 3 or 4

(1) Measure the pin voltage when a current of I_DIODE=50 μA flows from the LOGIC pin to the GND, without supplying VBB1

and VBB2 to the IC. This measurement is of the V_Fvoltage inside the diode.

(2) Measure the temperature characteristics of this pin voltage. (V_Fhas a linear negative temperature factor against the

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

pin voltage.

(3) Supply VBB1 and VBB2, confirm the LOGIC pin voltage while running the motor, and calculate approximately the chip

temperature from the results of (2).

-V_F[mV]

LOGIC pin

Internal Circuit

I_DIODE

V_F

25

150

Chip Temperature Tj[°C]

Figure 7. Model Diagram for Measuring Chip Temperature

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BD68888AEKV

Application Example

Logic input pin

See P.5 for detail.

Bypass capacitor.

Setting range is

Regulator

PHASE1

PHASE2

I01

RESET

100μF to 470μF (electrolytic)

0.01μF to 0.1μF (multilayer

ceramic etc.)

Refer to P.5 for detail.

Be sure to short VBB1 & VBB2.

UVLO

OVLO

TSD

Interface

I11

I02

I12

OCP

VREF1

VREF2

2bit DAC

VBB1

SENSE1

OUT1A

0.1 µF

100 µF

SENSE2

OUT1B

SENSE1

Set the output current.

Input by resistor divider.

Refer to P.6 for detail.

Blank time

PWM control

Control

logic

Pre-

driver

VBB1

OSC

OUT2A

OUT2B

SENSE2

Mix decay

control

VREF3

VREF4

2bit DAC

VBB2

SENSE3

OUT3A

SENSE4

OUT3B

SENSE3

Blank time

PWM control

Control

logic

Pre-

driver

VBB2

OSC

OUT4A

Logic input pin

See P.5 for detail.

OUT4B

SENSE4

Mix decay

control

Resistor for current

detection

Setting range is

0.1Ω to 0.3Ω.

Refer to P.6 for

detail.

PHASE3

PHASE4

I03

Interface

I13

I04

I14

PS

GND

Figure 8. BD68888AEKV Block Diagram and Applied Circuit Diagram

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BD68888AEKV

I/O Equivalence Circuit

PHASEx^{(Note 23)}

PS

Internal

Circuit

I0x^{(Note 24)}

I1x^{(Note 25)}

10kΩ

VREFx^{(Note 26)}

SENSEx^{(Note 27)}

215kΩ

5kΩ

100kΩ

VBB1, VBB2

OUTxA^{(Note 28)}

OUTxB^{(Note 29)}

SENSEx

Internal

Circuit

5kΩ

(Note 23) x=1, 2, 3 or 4

(Note 24) x=1, 2, 3 or 4

(Note 25) x=1, 2, 3 or 4

(Note 26) x=1, 2, 3 or 4

(Note 27) x=1, 2, 3 or 4

(Note 28) x=1, 2, 3 or 4

(Note 29) x=1, 2, 3 or 4

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BD68888AEKV

Operational Notes

1.

2.

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.

Power Supply Lines

Design the PCB layout pattern to provide low impedance supply lines. 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.

4.

Ground Voltage

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

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.

6.

Recommended Operating Conditions

The function and operation of the IC are guaranteed within the range specified by the recommended operating

conditions. The characteristic values are guaranteed only under the conditions of each item specified by the electrical

characteristics.

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.

7.

8.

Operation Under Strong Electromagnetic Field

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

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.

9.

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.

10. 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.

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BD68888AEKV

Operational Notes – continued

11. 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.

Resistor

Transistor (NPN)

Pin A

Pin B

B

E

C

Pin A

B

C

E

P

P⁺

N

P⁺

P

P⁺

N

Parasitic

Elements

Parasitic

Elements

P Substrate

GND GND

P Substrate

GND

Parasitic

Elements

Parasitic

Elements

N Region

close-by

Figure 9. Example of monolithic IC structure

12. Ceramic Capacitor

When using a ceramic capacitor, determine a capacitance value considering the change of capacitance with

temperature and the decrease in nominal capacitance due to DC bias and others.

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 maximum junction temperature 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 power 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.

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BD68888AEKV

Ordering Information

E K V

B D 6 8 8 8 8 A

-

E 2

Package

Packing and Forming specification

E2: Embossed tape and reel

Part Number

EKV

: HTQFP48V

Marking Diagram

HTQFP48 V (TOP VIEW)

Part Number Marking

BD68888A

LOT Number

Pin 1 Mark

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BD68888AEKV

Physical Dimension and Packing Information

Package Name

HTQFP48V

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BD68888AEKV

Revision History

Date

Revision

001

Changes

17.May.2018

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 equipment (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：	BD68888AEKV
厂家：	ROHM
描述：	BD63888AEKV是额定电源36V、额定输出电流1.2A的低功耗双极PWM恒流驱动器。输入接口采用CLK-IN驱动方式，通过内置DAC，励磁模式可适用FULL STEP、HALFSTEP(2种)、QUATER STEP模式，是可驱动2个双极型步进电机的电机驱动器。另外，也可使用一个系统电源进行驱动，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：1824K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

BD68888AEKV [ROHM]

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