Datasheet FAN8725 Datasheet (Fairchild Semiconductor)

FAN8725 (KA3025)

Spindle Motor and 5-Channel Motor Driver

www.fairchildsemi.com

Features

Common

• Built-in thermal shutdown circuit (TSD)

• Built-in power save circuit

• 3 Independent voltage source

• Corresponds to 3.3V or 5V DSP

Spindle

• Built-in hall bias

• Built-in FG signal output circuit

• Built-in rotational direction detecting circuit

• Built-in protection circuit for reverse rotation

• Built-in short brake circuit

BTL (5-channel)

• Built-in 5-CH balanced transformerless (BTL) driver

• Built-in Level shift circuit

• Independent voltage sources

• VM2 = CH1,CH2 / VM3 = CH3, CH4 ,CH5

Description

The FAN8725 is a monolithic IC suitable for a 3-phase
BLDC spindle motor driver and 5-ch motor drivers which
drives the focus actuator, tracking actuator, loading motor,
stepping motor driver of the CD-media systems.

48-QFPH-1414

Typical Applications

• Compact disk R OM (CD-ROM)

• Compact disk RW (CD-RW)

• Digital video disk ROM (DVD-ROM)

• Digital video disk RAM (DVD-RAM)

• Digital video disk Player (DVDP)

• Other compact disk media

©2000 Fairchild Semiconductor International

Ordering Information

Device Package Operating Temp.

FAN8725 48-QFPH-1414 −35°C ~ +85°C

Rev. 1.0.1

March. 2000.

1

FAN8725 (KA3025)

Pin Assignments

VH

48 47 46 45 44 43 42 41 40 39 38 37

PC1

EC

ECR

PS

SB

VREF

SVCC2

VM3

OUT5

IN5

PGND3

H1+

H1-

H2+

H2-

H3+

H3-

FG

DIR

SVCC1

VM1

CS1

PGND1

1

2

3

4

5

6

DO5 -

36

35

DO5+

DO4 -

34

DO4+

32

DO3 -

32

DO3+

31

FAN8725

7

8

9

10

11

12

30

PGND2

DO2 -

29

DO2+

28

DO1 -

27

26

DO1+

OUT1

25

13 14 15 16 17 18 19 20 21 22 23 24

A2

A3

A1

SGND2

OUT4

IN4

OUT3

IN3

IN2

OUT2

VM2

2

IN1

Pin Definitions

Pin Number Pin Name I/O Pin Function Description

1 H1- I Hall 1(-) input
2 H1+ I Hall 1(+) input
3 H2+ I Hall 2(-) input
4 H2- I Hall 2(+) input
5 H3+ I Hall 3(-) input
6 H3- I Hall 3(+) input
7 FG O Frequency Generator output
8 DIR O Rotation direction output

9 SVCC1 - Spindle Signal supply voltage
10 VM1 - Spindle power supply
11 CS1 I Spindle current sense
12 PGND1 - Spindle power ground
13 A1 O 3-phase output1
14 A2 O 3-phase output2
15 A3 O 3-phase output3
16 SGND2 - CH signal ground
17 IN4 I OP-Amp CH 4 input(-)
18 OUT4 O OP-Amp CH 4 output
19 IN3 I OP-Amp CH 3 input(-)
20 OUT3 O OP-Amp CH 3 output
21 IN2 I OP-Amp CH 2 input(-)
22 OUT2 O OP-Amp CH 2 output
23 VM2 - CH1/CH2 power supply
24 IN1 I OP-Amp CH 1 input(-)
25 OUT1 O OP-Amp CH 1 output
26 DO1+ O Channel 1 output (+)
27 DO1 - O Channel 1 output (−)
28 DO2+ O Channel 2 output (+)
29 DO2 - O Channel 2 output (−)
30 PGND2 - CH1/CH2 power ground
31 DO3+ O Channel 3 output (+)
32 DO3 - O Channel 3 output (−)
33 DO4+ O Channel 4 output (+)

FAN8725 (KA3025)

3

FAN8725 (KA3025)

Pin Definitions (Continued)

Pin Number Pin Name I/O Pin Function Description

34 DO4 - O Channel 4 output (−)
35 DO5+ O Channel 5 output (+)
36 DO5- O Channel 5 output (−)
37 PGND3 - CH3/CH4/CH5 power ground
38 IN5 I OP-Amp CH 5 input(-)
39 OUT5 O OP-Amp CH 5 output
40 VM3 - CH3/CH4/CH5 power supply
41 SVCC2 - CH Signal supply voltage
42 VREF I BTL reference voltage
43 SB I Short brake
44 PS I Power save
45 ECR I Torque control reference
46 EC I Torque control
47 PC1 - Phase compensation capacitor
48 VH I Hall bias

Notes:

BTL drive part symbol(+,- outputs of drives) is determined according to the polarity of input pin.
(For example, if the voltage of pin 24 is high, the output of pin 26 is high)

4

Internal Block Diagram

FAN8725 (KA3025)

H1+

H1 -

H2+

H2 -

H3+

H3 -

FIN(GND)

FG

DIR

PC1

EC

CS1VM

ECR

454647

Absolute Values

Output
Current Limit

VH

48

Hall

1

2

3

4

5

Bias

Hall Amp

SB

PS

4344 42 41 40 39 38 37

Current
Sense Amp

FIN(GND)

VREF

SVCC2

VM3

OUT5

CH5

X8

CH4

X8

IN5

PGND3

36

35

34

33

32

DO5 -

DO5+

DO4 -

DO4+

DO3 -

CH3

6

Detection

FG

Generator

7

8

Logic

Reverse
Rotation

Short
Brake

VM3

VM2

R

R

VM3

R

R

VM2

X8

CH2

X5

VM3

VM2

31

30

29

DO3+

FIN(GND)

PGND2

DO2 -

SVCC1

VM1

CS1

PGND1

10

11

12

9

Distributor

Driver

13 16

14 18

A1

A2

15

A3

17

IN4

SGND2

OUT4

FIN(GND)

5

19 20

IN3

21

OUT3

IN2

CH1

X5

22 23

OUT2

VM2

24

IN1

28

27

26

25

DO2+

DO1 -

DO1+

OUT1

FAN8725 (KA3025)

Equivalent Circuits (Spindle Part)

HALL INPUT DRIVER OUTPUT

Pin

10

Pin

11

Pin

1,3,5

22.5Ω

1KΩ 1KΩ

22.5Ω

Pin
2,4,6

15KΩ

TORQUE CONTROL INPUT HALL BIAS INPUT

Pin 45

22.5Ω

22.5Ω

Pin 46

1KΩ

1KΩ

+

Pin 48

5Ω

-

POWER SAVE INPUT SHORT BRAKE INPUT

Pin 44

22.5Ω

40KΩ

30KΩ

Pin 43

22.5Ω

1KΩ

Pin 13,14,15

100KΩ

20KΩ

FG OUTPUT DIR OUTPUT

10KΩ

Vcc

22.5Ω
Pin

7

Vcc

30KΩ

6

22.5Ω
Pin 8

Equivalent Circuits (BTL Part)

OP-AMP INPUT OP-AMP OUTPUT

FAN8725 (KA3025)

Pin
24,21,
19,17,38

40kΩ

20kΩ

22.5Ω

20KΩ

1KΩ

20KΩ

DRIVE OUTPUT VREF

CH-O

20kΩ

(Pin 26,28,31,33,35 )

CH-O
(Pin 27,29,32,34,36)

Pin 42

22.5Ω

20KΩ

1KΩ

Pin
25,22,20,18,39

20KΩ

7

FAN8725 (KA3025)

Absolute Maximum Ratings (Ta = 25°°°°C)

Parameter Symbol Value Unit

Supply Voltage (Spindle Signal) SV
Supply Voltage (BTL Signal) SV
Supply Voltage (Spindle Motor) V
Supply Voltage (BTL CH1/2) V
Supply Voltage (BTL CH3/4/5) V
Power dissipation P
Operating Temperature Range T
Storage temperature Range T
Maximum Output Current (Spindle) I
Maximum Output Current (BTL) I

NOTE:

1. When mounted on 70mm × 70mm × 1.6mm PCB (Phenolic resin materi al)

2. Power dissipation is reduced 24mW/°C for using above Ta=25°C

3. Do not exceed P

and SOA (Safe Operating Area)

D

CC1max

CC2max
M1max
M2max
M3max

D
OPR
STG

Omaxa
Omaxb

Power Dissipation Curve

7V
15 V
15 V
15 V
15 V

note

3.0

W

-35 ~ +85 °C

-55 ~ +150 °C

1.3 A

0.6 A

Pd [mW]

3,000

2,000

1,000

0

0 85

Recommended Operating Conditions (Ta = 25°°°°C)

Parameter Symbol Min. Typ. Max. Unit

Operating Supply Voltage (Spindle Signal) SV
Operating Supply Voltage (BTL Signal) SV
Operating Supply Voltage (Spindle Motor) V
Operating Supply Voltage (BTL CH1/2) V
Operating Supply Voltage (BTL CH3/4/5) V

CC1

CC2
M1
M2
M3

1751501251005025

Ambient Temperature, Ta [°C]

4.5 – 5.5 V

10.8 – 13.2 V

10.8 – 13.2 V

4.5 – SV

4.5 – SV

CC2
CC2

V
V

8

Electrical Characteristics (Ta = 25°°°°C)

Parameter Symbol Condition Min. Typ. Max. Units

FULL CHIP

Quiescent Circuit Current 1 I
Quiescent Circuit Current 2 I
Quiescent Circuit Current 3 I

CC1
CC2
CC3

POWER SAVE
On Voltage Range V
Off Voltage Range V

PSon
PSoff

HALL BIAS

Hall Bias Voltage V

HB

HALL AMP

Hall Bias Current I
Common Mode Input Range V
Minimum in Level V
H1 Hysteresis V

HA
HAR

INH

HYS

TORQUE CONTROL

Ecr In Voltage Range E
Ec In Voltage Range E
Offset Voltage (-) E
Offset Voltage (+) E

In Current E

E

C

E

In Current E

CR

In/output Gain G

CR

C

Coff-

Coff+

Cin

CRin

EC

FG

FG Output Voltage (H) V
FG Output Voltage (L) V

FGh

FHl

Duty(Reference Value) R

OUTPUT BLOCK

Saturation Voltage (upper TR) V
Saturation Voltage (lower TR) V
Torque Limit Current I

Oh

Ol

TL

DIRECTION DETECTOR

DIR Output Voltage (H) V
Dir Output Voltage (L) V

DIRh

DIRl

SHORT BRAKE

On Voltage Range V
Off Voltage Range V

SBon
SBoff

FULL CHIP (PS=0V) – 0 0.2 mA
SPINDLE (PS=5V) – 5 10 mA
BTL ( PS=5V) – 20 30 mA

L-H Circuit On 2.5 – Vcc V
H-L Circuit Off – – 1.0 V

IHB=20mA 0.4 1.0 1.8 V

E

C

E

CR

EC=1.9V -3 -0.5 – uA
ECR=1.9V -3 -0.5 – uA
ECR=2.5V, RCS=0.5Ω 0.56 0.70 0.84 A / V

IFG= -10uA 4.5 4.9 V
IFG=10uA – – 0.5 V

CS

IO= -300mA – 1.0 1.4 V
IO=300mA – 0.4 0.7 V
RCS=0.5Ω 560 700 840 mA

IFG=-10uA 4.5 4.7 V
IFG=10uA – – 0.5 V

FAN8725 (KA3025)

- –0.52uA

- 1.5–4.0V

- 100 – – mVpp

- 52040mVpp

- 0.2–4.0V

- 0.2–4.0V

=1.9V -80 -50 -20 mV

=1.9V 205080mV

CC

V

=0.5Ω 50 %

- 2.5 – V

CC

V

- 0–1.0V

9

FAN8725 (KA3025)

ELECTRICAL CHARACTERISTICS (continued)

BTL Drive Part (Ta=25°°°°C, SV

Parameter Symbol Condition Min. Typ. Max. Units

CH1/CH2

Output Offset Voltage1,2 V
Maximum Output Voltage1,2 V
Voltage Gain G

CH3/CH4/CH5

Output Offset Voltage3,4,5 V
Maximum Output

Voltage3,4,5
Voltage Gain G

OP-AMP CIRCUIT

Common Mode Input Range V
Input Bias Current Ι
Low Level Output Voltage V
High Level Output Voltage V
Output Driving Source Current I
Output Driving Sink Current I

=12V, VM2=5V, VM3=12V, RL=8, 24ΩΩΩΩ)

CC2

OF1/2

OM1/2

VC1/2

OF3/4/5

V

OM3/4/5

VC3/4/5

ICM

B
CL
OH

SOURCE

SINK

VM2=5V,RL=8Ω 3.6 4.0 – V
VIN=0.1Vrms, 1kHz 12.0 14.0 16.0 dB

VM3=12V,RL=24Ω 8.4 10.5 – V

VIN=0.1Vrms, 1kHz 16.0 18.0 20.0 dB

- -95 – 95 mV

- -95 – 95 mV

- 0–11.0V

- -300 -30 nA

- -0.20.5V

- 10.0 11 – V

- 14.0–mA

- 510–mA

10

FAN8725 (KA3025)

Application Information

1. TORQUE CONTROL & OUTPUT CURRENT CONTROL

V

M

+

Rcs

V

M

Ecr

Torque AMP

+

-

Ec

ECR-EC

+

V

AMP

-

Current Sense AMP

-

+

TSD

Gain

Controller

1) B y ampl ifyi ng th e volta ge diffe rence betwe en Ec and Ecr from Servo IC, the Torque Sense AMP prod uce s the in put vo lt­age(V

) for the Current Sense AMP.

AMP

Vcs

-

Driver

Io

M

2) The output current (I

) is converted into the voltage (VCS) through the sense resistor (RCS) and compared with the V

O

By the negative feedback loop, the sensed output voltage, VCS is equal to the input V
early controlled by the input V

3) The signals, E

and ECR can control the velocity of the Motor by controlling the output current (IO) of the Driver.

C

AMP

.

4) The range of the torque voltage is as shown below.

Current

[mA]

700

Reverse

Ecoff-

Ecoff+

Forward

E

CR

E

CR

6

-1.0 V 0

-50mV

The input range of E

CR, EC

50mV

1.0 V

is 0.2 V ~ 4.0 V ( R

E

= 0.5[Ω] )

CS

CR -EC

. The output current (IO) is lin-

AMP

Rotation
> Ec Forward rotation
< Ec Stop after detecting re-

verse rotation

AMP

.

11

FAN8725 (KA3025)

2. SHORT BRAKE

MOTOR

ON

OFF

Vcc

OFF

43

1KΩ

ON

20KΩ

13

14

15

Pin # 43 Short Brake

HIGH ON
LOW OFF

When the pick-up mechanism moves from the inner to the outer spindle of the CD, the Brake function of the reverse voltage is
commonly employed to decrease the rotating velocity of the Spindle Motor.

However, if the Spindle Motor rotates rapidly, the Brake function of the reverse voltage may produce much heat at the Drive
IC.

To enhance the braking efficiency, the Short Brake function is added to FAN8725. When the Short Brake function is activated,
all upper Power TRs turn off and all lower Power TRs turn on, so as to make the rotating velocity of the motor slow down. But
FG and DIR functions continue to operate normally.

3. POWER SAVE

Vcc

Start

Stop

44

40KΩ

30KΩ

Pin # 44 Power Save

HIGH Motor Drive Ouput Activated
LOW Sleep mode

When PowerSave(PS) function is activated, the chip is deactivated.

IC bias

12

FAN8725 (KA3025)

4. TSD (THERMAL SHUTDOWN)

Gain

Controller

BIAS

Q2

When the chip temperature rises up to about 175C(degree), the Q2 turns on and the output driver shuts down. When the chip
temperature falls off to about 150C(degree), then the Q2 turns off and the driver operates normally. TSD has the temperature
hysteresis of about 25C(degree).

-- The TSD circuit shuts down all the power drives(spindle and BTL power drives) excluding both CH1 and CH2 power
drives(actuator part).

5. ROTATIONAL DIRECTION DETECTION

Vcc

H2+

H2-

H3+

H3-

+

­D

+

-

Q

CK

D-F/F

DIR

8

Rotation DIR
Forward Low
Reverse High

8

1) The forward and the reverse rotations of the CD are detected by using the D-F/F and the truth table is shown in the above.

2) The rotatio nal direction of the CD can be explained by th e output waveform of the Hall sensors. Let the three outputs of
Hall sensors be H1, H2 and H3 respectively.
When the spindle rotates in reverse direction, the Hall sensor output waveform are sh own in Fig.(a). Thus the phases
ordered in H1→H2→H3 with a 120° phase difference.

H1

H2

H3

(a) Reverse rotation

13

FAN8725 (KA3025)

On the other hand, if the spindle rotates in forward rotation, the phase relationship is H3->H2->H1 as shown in Fig.(b)

H1

H2

H3

(b) Forward rotation

The direction output ,detector is Low, when the spindle rotates forward, and HIGH in the reverse direction.

6. REVERSE ROTATION PREVENTION

EC

ECR

H2+

H2-

H3+

H3-

+

-

+

-

+

-

DQ

CK

D-F/F

Low Active

A

Current
Sense
Amp

Gain

Controller

Driver

M

1) When the output of the OR Gate, A is LOW, it steers all the output current of the current sense Amp to the Gain Controller
zero. The output current of the Driver becomes zero and the motor stops.

2) As in the state of the forward rotation, the D-F/F output, Q is HIGH and the motor rotates normally. At this state, if the
control input is changed such that EC>ECR, then the motor rotates slowly by the reverse commutation in the Driver. When
the motor rotates in reverse direction, the D-F/F output becomes Low and the OR Gate output, b ecomes LOW. This pre­vents the motor from rotating in reverse direction. The operation principle is shown in the table and the flow chart.

14

FAN8725 (KA3025)

Forward rotation at EC < ECR

Rotating speed is decreased due to reverse torque at EC >ECR. (Motor still rotates forward)

At the moment that the motor rotates in reverse, the reverse rotation preventer makes the output power transistor open.

Rotating reverse at short time due to motor inertia

Stop within 1/6 turn reverse rotating

Rotation H2 H3

D-F/F

(Q)

Reverse Rotation Preventer

E

CR>EC

EC>E

Forward H H→LH Forward ­Reverse L H→L L - Brake and Stop

7. FG OUTPUT

Vcc

7

FG

H3+
H3-

+

-

8. HALL SENSOR CONNECTION

Vcc

Vcc

CR

HALL 1 HALL 2

HALL 1

HALL 3

48

VH

HALL 2

HALL 3

48

VH

15

FAN8725 (KA3025)

9. CONNECT A BYPASS CAPACITOR, FROM ALL THE SUPPLY VOLTAGE SOURCES TO GROUND.

(Typically 0.1uF, or even higher)

SVcc1, SVcc2, VM1, VM2, V

M3

0.1uF

10. THE HEAT RADIATION FIN IS CONNECTED TO THE INTERNAL GND OF THE PACKAGE.

Connect the FIN to the external GND.

16

11. INPUT-OUTPUT TIMING CHART

H1 +

H2 +

H3 +

A1 output current

(H1 -)+(H2 +)

FAN8725 (KA3025)

A1 output voltage

A2 output current

(H2 -)+(H3 +)

A2 output voltage

A3 output current

(H3 -)+(H1 +)

A3 output voltage

17

FAN8725 (KA3025)

12. BTL DRIVE PART

23 40

VM2

(VM3)

27 29 32 34 36

R

−

R

(VM3)

+

VM2

25K

(40K)

DO

−

+

−

10K

10K

42

Vref

M

Power amp

25K

(40K)

(40K)

+

−

25K

DO+

+

−

10K

10K

Error
Amp

+

171921 24 38

26 28 31 33 35

25K

(40K)

18 20 22

−

R1

24 39

R2

• The reference voltage REF is given externally through pin 42.

• The error amp output signal is amplified by R2 / R1 times and then fed to the power amp circuit.

• The power amp circuit produces the differential output voltages and drives the two output power amplifier circuit.

• Since the differential gain of the output amplifiers of CH1/CH2 is equal to 2 × (25K / 10K) , the output signal of the error

amp is amplified by (R2 / R1) × 5.

• Since the differential gain of the output amplifiers of CH3/CH4/CH5 is equal to 2 × (40K / 10K) , the output signal of the

error amp is amplified by (R2 / R1) × 8.

• If the total gain is insufficient, the input error amp can be used to increase the gain.

• The CH1/CH2 are generally used as actuator drive circuit so this channels are not affected by TSD circuit.

18

Typical Application Circuits

SLED2
SIGNAL

FAN8725 (KA3025)

VM1

SVCC
1

HALL1

HALL2

HALL3

SERVO
SIGNAL

VH

48 47 46 45 44 43 42 40 39 3841 37

1

H1+

2

H1 -

3

H2+

4

H2 -

5

H3+

6

H3 -

PC1

EC

POWER
SAVE

PS

ECR

SHORT
BRAKE

SB

SVCC2 VM3

VREF

SVCC2

VM3

FAN8725

7

FG

8

DIR

9

SVCC1

10

VM1

11

CS1

PGND1

12

A2

A1

13 14 15 16 17 18 19 21 22 2320 24

A3

SGND2

IN4

OUT4

IN3

OUT3

IN2

OUT5

OUT2

DO5 -

IN5

DO5+

DO4 -

DO4+

DO3 -

DO3+

PGND2

DO2 -

DO2+

DO1 -

DO1+

VM2

VM2

IN1

PGND3

36

35

34

33

32

31

30

29

28

27

26

OUT1

25

M

M

FOCUS
ACTUATOR

SLED
(stepping)
MOTOR

LOADING
MOTOR

TRACKING
ACTUATOR

SLED1
SIGNAL

19

LOADING
SIGNAL

TRACKING
SIGNAL

FOCUS
SIGNAL

FAN8725 (KA3025)

DISCLAIMER

FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURT HER NOTICE TO ANY
PRODUCTS HEREI N TO IMPROVE RELIABILITY, FUNCTIO N OR DESIGN. FAIRCH IL D DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER IT S PATENT RIGHTS, NOR THE RIGHTS OF OTHE RS.

LIFE SUPPORT POL I CY

FAIRCHILD’S PR ODUCTS ARE NOT AUTH ORIZED FOR USE AS C RITICAL COMPONENT S IN LIFE SUPPORT DE VICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
INTERNATIONAL. As used herein:

1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with

2. A critical component in any component of a life support
device or sy stem whose fai lure to perform can be
reasonably expec ted to cause the failur e of the life support
device or system, or to affect its safety or effec t iv ene ss .

instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.

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12/1/00 0.0m 001

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