ROHM BD7755RFV Technical data

System Motor Driver ICs for CD / DVD / Blu-ray Drive and Recorder

System Motor Driver IC for Half Height Drive (Sensor less)

BD7755RFV

●Description

BD7755RFV are ICs, developed for the spindle motor, actuator coil, tilt coil, stepping motor, SA stepping motor and the loading motor drive of the desktop Blu-ray drive and Blu-ray recorder. Spindle driver adopted sensorless drive system, and the hall sensor (3 pieces) of the motor position detection is not needed, it is suitable for making of flexible cable conserve wiring and the reductions of external parts. The low rotation mode is built in, and stability and low-speed a rotation is achieved. The spindle, stepping and SA stepping use power MOSFET to reduce power consumption and the actuator, tilt, and loading driver use a linear BTL drive system to reduce noise.

●Features

1) The low-speed stability rotation is achieved with built-in the low rotation mode.

2) The hall sensor is unnecessary according to 3 aspect sensorless drive system.

3) The spindle motor driver achieves stability high speed start by ROHM's own energizing method.

4) Highly effective spindle, stepping and SA stepping is achieved by PWM control driver. And the output current detection resistance of stepping and SA stepping is unnecessary by built-in internal detection circuit.

5) The actuator, tilt and loading driver achieve low noise by using linear BTL drive system.

6) ON/OFF of loading and other channels, brake mode of spindle driver and standby mode are selectable by the two control terminals.

7) Built-in thermal-shut down circuit.

8) Improved heat radiation efficiency utilizing HTSSOP package.

●Applications

For desktop Blu-ray drive

●Absolute maximum ratings

No.10012EAT01

Parameter Symbol Ratings Unit

POWER MOS power supply voltage 1 SPVM, SLVM 15

POWER MOS power supply voltage 2 SAVM 7

Preblock/BTL power block power supply voltage Vcc, AVM, LDVM 15

PWM control block power supply voltage DVcc 7

Power dissipation Pd 1.5

Operating temperature range Topr -20 ~ 70

Storage temperature Tstg -55 ~ 150

Junction temperature Tjmax 150

#1 POWER MOS output terminals (40~43pin, 46～48pin) are contained. #2 POWER MOS output terminals (35~38pin) are contained. #3 PCB mounting (70mmX70mmX1.6mm, occupied copper foil is less than 3%, glass epoxy standard board). Reduce by 12mW/℃ over 25℃

#1

#2

#3

V

W

℃

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BD7755RFV

Technical Note

●Recommended operating conditions

(Set the power supply voltage with consideration to power dissipation)

Parameter Symbol

Spindle / Sled motor driver power block power supply voltage

Min. Typ. Max.

SPVM,SLVM － Vcc

Ratings

#4

－ V

Pre block power supply voltage Vcc 10.8 12 13.2 V

Loading driver power block supply voltage LDVM 4.3 5.0 Vcc V

Unit

SA, Actuator driver power block power supply voltage

SAVM,AVM 4.3 5.0 5.5 V

PWM control block power supply voltage DVcc 4.3 5.0 5.5 V

Spindle driver output current Iosp － 1.0 2.5 #5A

Actuator, SA, sled, loading motor driver output current

#4 Set the same supply voltage to SPVM, SLVM and Vcc. #5 The current is guaranteed 3.5A in case of the Short-circuit braking mode and the current which is turned on/off in a duty-ratio of less than 1/10 with a maximum on-time of 5msec

Ioo － 0.5 0.8 A

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BD7755RFV

●Electrical characteristics (Unless otherwise noted, Ta=25℃, Vcc=SPVM=SLVM=12V, DVcc=AVM=SAVM= LDVM=5V, Vc=1.65V,RL=8Ω,RLSP=2Ω)

Parameter Symbol

Circuit current

Quiescent current 1 IQ1 － 14 30 mA Vcc(Loading OFF) Quiescent current 2 IQ2 － 7.5 16 mA Vcc(Loading ON) Quiescent current 3 IQ3 － 7 14 mA DVcc Standby-on current 1 IST1 － 1.1 2.4 mA Vcc Standby-on current 2 IST2 － 0.16 0.4 mA DVcc

Sled driver block

Input dead zone (one side) VDZSL 0 30 80 mV

Input output gain gmSL 0.75 1.0 1.25 A/V Output On resistor

(top and bottom) Output limit current ILIMSL 0.8 1.1 1.4 A

PWM frequency fosc － 100 － kHz

Spindle driver block<Torque instruction input / output>

Input dead zone (one side)1 VDZSP1 20 55 90 mV VLRPM=L

Input dead zone (one side)2 VDZSP2 20 240 450 mV VLRPM=H

Input output gain 'H' gmSPH 2.68 3.5 4.32 A/V VLRPM=L

Input output gain 'L' gmSPL 0.53 0.7 0.87 A/V VLRPM=H Output On resistor (top and bottom) RONSP － 1.0 1.7 Ω IL=500mA Output limit current ILIMSP 1.35 1.6 1.85 A RSPLIM=1.5kΩ PWM frequency fosc － 167 － kHz

FG output, PRTFLG output

High voltage VOH － 4.9 － V 100kΩ pull up to DVcc Low voltage VOL － 0.1 － V

Focus / Tracking / Tilt driver block

Output offset voltage VOFA -50 0 50 mV Output saturation voltage (top and bottom) VOHA － 0.9 1.8 V IL=500mA

Voltage gain H GVAH 19.6 21.6 23.6 dB VLRPM=L

Voltage gain L GVAL 13.6 15.6 17.6 dB VLRPM=H

SA stepping driver block

Input dead zone (one side) VDZSA 40 80 160 mV

Input output gain gmSA 0.15 0.2 0.25 A/V Output On resistor (top and bottom) RONSA － 1.3 2.5 Ω IL=200mA

Output limit current ILIMSA 0.28 0.4 0.52 A PWM frequency fosc － 100 － kHz

Loading driver block

Output offset voltage VOFLD -50 0 50 mV Output saturation voltage (top and bottom) 1 VOLD1 － 0.7 1.6 V IL=500mA LDVM=5V Output saturation voltage (top and bottom) 2 VOLD2 － 2.1 3.6 V IL=500mA LDVM=12V

Voltage gain GVLD 15.5 17.5 19.5 dB

CTL1,CTL2, LRPM

Input high voltage VIH 2.5 － 3.7 V Input low voltage VIL GND － 0.5 V

Others

VC drop-muting VMVC 0.4 0.7 1.0 V

Vcc drop-muting VMVcc 3.45 3.85 4.25 V

*This product is not designed to be radiation-resistant.

RONSL － 2.2 3.8 Ω IL=500mA

MIN. TYP. MAX.

Limits

Unit Conditions

Technical Note

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BD7755RFV

●Block diagram

Technical Note

C_OUT

C_COM

FG

CTL1

CTL2

LRPM

PRTLIM

SPIN

LDIN

LDVM

LDO+

LDO-

AGND

FCO+

FCO-

TLO+

TLO-

TKO+

TKO-

TKIN

TLIN

1

2

3

4

STBY

BRAKE

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

LRPM

PRTLIM

80kΩ

40kΩ

LDVM/2

80kΩ

160kΩ

AVM/2

160kΩ

160kΩ 160kΩ

160kΩ

AVM/2

160kΩ 160kΩ

160kΩ

AVM/2

160kΩ

CONTROL

SHIFT

40kΩ

80kΩ

26.5kΩ

LEVEL

×2

T.S.D

CURR.

LIMIT

CURR.

LIMIT

CURR.

FEED

CURR.FEED

OSC

CURR.FEED

OSC

CURR.FEED

BEMF

DETECTER

FFFF

CURR.

Logic

OSC

PRE

Logic

PRE

Logic

PRE

Logic

PRE

Logic

54

LIMIT

SPLIM

53

GND

52

SPVM

51

COM

50

W

49

N.C.

48

V

47

U

46

N.C.

45

SPGND

44

SLVM

43

SLO2-

42

SLO2+

41

SLO1-

40

SLO1+

39

SL/SAGND

38

SAO2-

37

SAO2+

36

SAO1-

35

SAO1+

34

SLDETOUT

FCIN

AVM

VC

VCC

PRTFLG

DVCC

22

23

24

25

26

27

PROTECT

LEVEL SHIFT

62.6kΩ

DETECTER

33

SLDET

32

SAVM

31

SLIN1

30

SLIN2

29

SAIN1

28

SAIN2

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BD7755RFV

●Pin description

No. Symbol Description No. Symbol Description

Technical Note

1 C_OUT

2 C_COM

3 FG Frequency generator output 30 SLIN2 Sled driver 2 input

4 CTL1 Driver logic control 1 input 31 SLIN1 Sled driver 1 input

5 CTL2 Driver logic control 2 input 32 SAVM SA driver power block power supply

6 LRPM Low rotation mode change terminal 33 SLDET Sled motor detection signal control input

7 PRTLIM

8 SPIN Spindle driver input 35 SAO1+ SA driver 1 positive output

9 LDIN Loading driver input 36 SAO1- SA driver 1 negative output

10 LDVM Loading driver block power supply 37 SAO2+ SA driver 2 positive output

11 LDO+ Loading driver positive output 38 SAO2- SA driver 2 negative output

12 LDO- Loading driver negative output 39 SL/SAGND

13 AGND BTL driver block GND 40 SLO1+ Sled driver 1 positive output

Smooth capacitor connection terminal (output side)

Smooth capacitor connection terminal (com side)

Adjustable resistor connection for actuator protection

28 SAIN2 SA driver 2 input

29 SAIN1 SA driver 1 input

34 SLDETOUT Sled motor detection signal output

Sled/SA driver block pre and power ground

14 FCO+ Focus driver positive output 41 SLO1- Sled driver 1 negative output

15 FCO- Focus driver negative output 42 SLO2+ Sled driver 2 positive output

16 TLO+ Tilt driver positive output 43 SLO2- Sled driver 2 negative output

17 TLO- Tilt driver negative output 44 SLVM Sled motor driver power supply

18 TKO+ Tracking driver positive output 45 SPGND Spindle driver power ground

19 TKO- Tracking driver negative output 46 N.C. N.C.

20 TKIN Tracking driver input 47 U Spindle driver output U

21 TLIN Tilt driver input 48 V Spindle driver output V

22 FCIN Focus driver input 49 N.C. N.C.

23 AVM Actuator driver block power supply 50 W Spindle driver output W

24 VC Reference voltage input 51 COM Motor coil center point input

25 Vcc Pre block power supply 52 SPVM Spindle driver power supply

26 PRTFLG Protection flag output 53 GND Pre block GND

27 DVcc PWM block control power supply 54 SPLIM

*Positive/negative of the output terminals is determined in reference to those of the input terminals.

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Adjustable resistor connection for spindle driver current limit

2010.06 - Rev.A

BD7755RFV

●Equivalent-circuit diagram of the terminals

Three-phase motor driver output BEMF voltage detection input

Technical Note

51

52pin

10k

5k

1

2

5k 5k 10k

53pin

47

52

48 50

45

PWM driver output SLED1,2 PWM driver output SA1,2 BTL driver output FC,TK,TL

40

42

44

39

41

43

35

37

32

39

36

38

14

16

18

13

23

15

17

19

BTL driver output LD BTL driver input FC,TK,TL,LD PWM driver input SLED1,2

11

13

10

12

20

22

21

25pin

9

200Ω

53pin

30

31

27pin

200Ω

53pin

PWM driver input SA1,2 PWM driver input Spindle Spindle current limit input

52pin

54

53pin

28

29

27pin

53pin

62.6kΩ

27pin

8

200Ω

53pin

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