Datasheet FAN8423D3 Datasheet (Fairchild Semiconductor)

FAN8423D3

3-Phase BLDC Motor Driver

www.fairchildsemi.com

Features

• 3-phase, full-wave, linear BLDC motor driver

• Power save at stop mode

• Built-in current limiter

• Built-in TSD (thermal shutdown) circuit

• Built-in 3X and 1X hall FG output

• Built-in hall bias circuit

• Built-in rotational direction detector

• Built-in reverse rotation preventer

• Built-in short braker

• Corresponds to 5 V DSP

Description

The FAN8423D3 is a monolithic IC, suitable for a 3-phase
spindle motor driver of a CD-media system.

28-SSOPH-375SG2

Typical Applications

• Compact disk ROM (CD-ROM) spindle motor

• Compact disk RW (CD-RW) spindle motor

• Digital video disk ROM (DVD-ROM) spindle motor

• Digital video disk RAM (DVD-RAM) spindle motor

• Digital video disk Player (DVDP) spindle motor

• Other compact disk media spindle motor

• Other 3-phase BLDC motor

©2000 Fairchild Semiconductor International

Ordering Information

Device Package Operating Temp.

FAN8423D3

FAN8423D3TF 28-SSOPH-375SG2

28-SSOPH-375SG2

−25°C ~ +75°C

−25°C ~ +75°C

Rev. 1.0.1

Oct. 2000.

FAN8423D3

Pin Assignments

CS1

VM

NC

VCC

S/S

FG1X

EC

FIN(GND)

ECR

DIR

FG3X

SB

PC1

FAN8423D3

1 2 3 4 5 6 7 8 9 10 11 12 13 14

NC

A3

NC

A2

NC

NC

A1

FIN(GND)

GND

H1+

H1-

H2+

H2-

Pin Definitions

Pine Number Pin Name I/O Pin Function Description

1 NC - No connection
2 A3 O Output (A3)
3 NC - No connection
4 A2 O Output (A2)
5 NC - No connection
6 NC - No connection
7 A1 O Output (A1)
8 GND - Ground

9 H1+ I Hall signal (H1+)
10 H1- I Hall signal (H1-)
11 H2+ I Hall signal (H2+)
12 H2- I Hall signal (H2-)
13 H3+ I Hall signal (H3+)
14 H3- I Hall signal (H3-)
15 VH I Hall bias
16 NC - No connection
17 PC1 - Phase compensation capacitor
18 SB I Short brake
19 FG3X O FG waveform (3X)
20 DIR O Rotational direction output
21 ECR I Output current control reference
22 EC I Output current control voltage
23 S/S I Power save (Start/Stop switch)
24 FG1X O FG waveform (1X)
25 VCC - Supply voltage (Signal)
26 NC - No connection
27 VM - Supply voltage (Motor)
28 CS1 - Output current detection

NC

H3+

VH

1516171819202122232425262728

H3-

2

Rev. 1.0.1
Oct. 2000.

Internal Block Diagram

CS1

VM

NC

28 27 26 25 24 23 22 21 20 19 18 17 16 15

VCC

FG1X

FG1X

Generator

S/S

Stop

Start

EC

Current Sense
Amp

GND

-

+

Output
Current Limit

Absolute
Values

Upper

Lower

Distribu-

Distribu-

FAN8423D3

ECR

DIR

FG3X

SB

PC1

NC

VH

Short

FG3X

tion

Logic

Brake

Generator

Reverse Rota-

tor

tion

Direc-

Detec-

Selector

Commutation

Hall Amp

Hall

TSD

1234567

NC

A3

NC

A2

NC

NC

A1

GND

8

91011121314

GND

H1-

H1+

H2-

H2+

H3-

H3+

Rev. 1.0.1
Oct. 2000.

3

FAN8423D3

Equivalent Circuits

Hall Input Driver Output

28

9

50Ω

11
13

1KΩ

1KΩ

50Ω

10
12
14

2274 7

Torque Control Input Hall Bias Input

50Ω

21

50Ω

22

+

-

15

100KΩ

Start/stop Input Short Brake Input

50Ω

23

40KΩ

30KΩ

50Ω

18

1KΩ

20KΩ

Fg Output Dir Output

Vcc

10KΩ

50Ω

4

19

24

Rev. 1.0.1
Oct. 2000.

30KΩ

Vcc

50Ω

20

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

Parameter Symbol Value Unit

Maximum supply voltage (Signal) V
Maximum supply voltage (Motor) V
Power dissipation P
Maximum output current I
Operating temperature range T
Storage temperature range T

NOTE:

1. When mounted on a 76 .2mm × 114mm × 1.57mm PCB (Phenolic resin material).

2. Power dissipation reduces 16.6mW/°C for using above Ta = 25°C

3. Do not exceed P

and SOA (Safe operating area).

D

CCmax

Mmax

D

Omax

OPR
STG

7V

15 V

note

2.5

1.3 A

-25 ~ +75 °C

-55 ~ +150 °C

Power Dissipation Curve

Pd (mW)

3,000

2,000

FAN8423D3

W

1,000

SOA

0

0 25 50 75 100 125 150 175

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

Parameter Symbol Min. Typ. Max. Unit

Supply Voltage V
Motor Supply Voltage V

cc
M

4.5 5 5.5 V

3.5 12 14 V

Ambient temperature, Ta [°C]

Rev. 1.0.1
Oct. 2000.

5

FAN8423D3

Electrical Characteristics

(Unless otherwise specified, Ta = 25 °C, Vcc=5 V, VM=12 V)

Parameter Symbol Condition Min. Typ. Max. Unit

Quiescent circuit current 1 I
Quiescent circuit current 2 I

cc1
cc2

START/STOP

On voltage range V
Off voltage range V

SSon
SSoff

HALL BIAS
Hall bias voltage V

HB

HALL AMP

Hall bias current I
Common-mode input range V
Minimum input level V
H1 hysteresis level V

HA
HAR

INH

HYS

TORQUE CONTROL

Ecr Input voltage range E
Ec Input voltage range E
Offset voltage (-) E
Offset voltage (+) E
Ec Input current E
Ecr Input current E
Input/output gain G

CR

C

Coff-

Coff+

Cin

CRin

EC

FG

FG output voltage (H) V
FG output voltage (L) V

FGh

FGl

Duty (reference value) - - - 50 - %

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

At stop mode - - 0.2 mA
At start mode - 5 10 mA

Output driver ON 2.5 - Vcc V
Output driver OFF 0.0 - 1.0 V

IHB=20 mA 0.4 1.0 1.8 V

--0.52µA

- 1.0 - 4.0 V

-60--mVpp

- 5 20 40 mVpp

- 1.0 - 4.0 V

- 1.0 - 4.0 V
Ec=2.5 V -80 -50 -20 mV
Ec=2.5 V 20 50 80 mV
Ec=2.5 V - 0.3 3 µA
Ecr=2.5 V - 0.3 3 µA
Ec=2.5 V, Rcs=0.5 Ω 0.41 0.51 0.61 A / V

Ifg=-10 µA4.54.9-V
Ifg=10 µA--0.5V

Io=-300 mA - 0.9 1.4 V
Io=300 mA - 0.4 0.7 V

RCS=0.5 Ω 560 700 840 mA

IFG=-10 µA4.54.7-V
IFG=10 µA--0.5V

-2.5-VccV

-0-1.0V

6

Rev. 1.0.1
Oct. 2000.

Electrical Characteristics (Continued)

Calculation of Gain & Torque Limit Current

FAN8423D3

Current / Voltage
Convertor

EC

ECR

+

Gm

−

Absolute
Values

0.255 is GM times R1, is a fixed value within IC.

Vmax (see above block diagram) is set at350mV.

Itl mA[]

VM VM

Negative

−

+
+

Vmax

−

AV⁄[]=

S

Feedback loop

Driver

350 mV[]

----------------------- -==

R

S

−

Vin

R1

+

VM

Max. output current limiting

0.255

Gain

-------------- -

Vmax

--------------- -

R

+

R

S

I

O

R

CS1 (Pin 28)

Power
Transistors

Commutation
Distributor

H1

S

H2

−

Output

V

S

Current sense

+

H3

I

O

U
V
W

Rev. 1.0.1
Oct. 2000.

7

FAN8423D3

Application Information

1. To rque Control & Output Current Control

V

M

+

Rcs

V

M

Current Sense AMP

-

+

TSD

Gain

Controller

Ecr

Torque AMP

+

-

Ec

ECR-EC

1) By amplifying the voltage difference between Ec and Ecr from Servo IC, the Torque Sense AMP produces the input
(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
(I

) is linearly controlled by the input V

O

3) As a result, the signals, E

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

C

AMP

.

Driver.

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

Current

[mA]

Reverse

Forward

E

700
500

6

The input range of E

-50mV

Ecoff-

Ecoff+

0.51[A/V]

0

CR

50mV

and EC is 1.0 V ~ 4 V ( RNF = 0.5[Ω] )

E

CR

. Therefore, the output current

AMP

Rotation

> Ec Forward rotation

CR

< Ec

Stop after detecting re­verse rotation

AMP

.

8

Rev. 1.0.1
Oct. 2000.

2. Short Brake

FAN8423D3

MOTOR

ON

OFF

Vcc

OFF

18

1KΩ

ON

20KΩ

2

4

7

Pin # 18 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, th e Brake function of the reverse v oltag e may produce more heat at the Drive
IC.

To remove this shortcoming and to enhance the braking efficiency, the Short Brake function is added to FAN8423D3. When
the Short Brake function is active, all upper Power TRs turn off and all lower Power TRs turn on. This slows down the motor.

3. Start/stop (Power Save)

Vcc

Start

Stop

Pin # 23 Start/Stop

High Operate

Low Stop

When Start/Stop function is active, all Power TRs turn off.

23

40KΩ

30KΩ

OFF

MOTOR

2

4

7

OFF

Rev. 1.0.1
Oct. 2000.

9

FAN8423D3

4. Ts d (Thermal Shutdown)

Gain

Controller

BIAS

Q2

When the chip temperature rises up to about 175°C, the Q2 turns on so that the output driver shuts down. When the chip tem­perature falls off to about 150°C, then the Q2 turns off so that the driver is to operate normally. TSD has the temperature hys­teresis of about 25°C.

5. Rotational Direction Detection

Vcc

H2+

H2-

H3+

H3-

+

­D

+

-

Q

CK

D-F/F

DIR

20

Rotation DIR
Forward Low
Reverse High

20

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

2) The rotational direction of the CD can be explained by the ou tput waveform of the Ha ll sensors. Let the three o utputs of
Hall sensors be H1, H2 and H3 respectively.
When the spindle rotates in reverse direction, the Hall sensor output waveform are shown in Fig.(a). Thus the phases are in
order H1→H2→H3 with a 120° phase difference.

H1

H2

H3

(a) Reverse rotation

On the other hand, if the spindle rotates in forward rotation, the phase relationship is H3→H2→H1 as show n in Fig.(b)

10

Rev. 1.0.1
Oct. 2000.

H1

H2

FAN8423D3

H3

(b) Forward rotation

Therefore, the output of the rotational direction detector is Low, when the spindle rotates forward, while HIGH as in the case
of the reverse rotation.

6. Reverse Rotation Pr evention

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.

Rotation H2 H3

D-F/F

(Q)

Reverse Rotation Preventer

E

C<ECR

EC>E

CR

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

Rev. 1.0.1
Oct. 2000.

11

FAN8423D3

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

7. Fg Output

H1-

H1+

24

FG1X

H2-

19

H2+

FG3X

H3-

H3+

8. Hall Sensor Connection

HALL 1 HALL 2

Vcc

Vcc

HALL 1

HALL 3

15

VH

HALL 2

HALL 3

15

VH

12

Rev. 1.0.1
Oct. 2000.

9. Connect A By-pass Capacitor, 0.1µµµµf Between The Supply Voltage Source

25

Vcc

0.1uF

(1) The heat radiation fin is connected to the internal Gnd of the package.

Connect that fin to the external Gnd.

FAN8423D3

Rev. 1.0.1
Oct. 2000.

13

FAN8423D3

10. Input-output Timing Chart

H1 +

H2 +

H3 +

A1 output current

(H1 -)+(H2 +)

A1 output voltage

A2 output current

(H2 -)+(H3 +)

A2 output voltage

A3 output current

(H3 -)+(H1 +)

A3 output voltage

14

Rev. 1.0.1
Oct. 2000.

Test Circuits

FAN8423D3

VM

10uA

14 VM5

5V

12V

A A

IM3

Rcs

V

0.5Ω

CS1 VM NC VCC SS ECFG1X ECR DIR FG3X SB PS1 NC VH

IM2

10uA

15

VM6

VR1

VR2

IM1

A A

VR3

IM2

V

VR5

10uA

15

VM6

0.1uF

FAN8423D3

A3 A2 A1 GND H1+ H1- H2+ H2- H3+ H3-

1234567 891011121314

IM4

IM5 IM6 IM7 IM8 IM9

SW3

c

VVV

a

A A A A A A

VR9

VR8

VR10 VR11 VR12 VR13

VM8

SW1

c

a

SW2

c

a

13

V

20mA

VM4

V

VM3

1516171819202122232425262728

b

SW13

a

V

VM1

12V

b

300mA

b

300mA

b

RL=5ΩRL=5ΩRL=5Ω

V

VM2

Rev. 1.0.1
Oct. 2000.

15

FAN8423D3

Typical Application circuits

HALL 1

HALL 2

1

NC

2

A3

NC

3

4

A2

5

NC

6

NC

7

A1

FAN8423D3

8

GND

9

H1+

10

H1−

11

H2+

12

H2−

CS1

VM

NC

VCC

FG1X

SS

EC

ECR

DIR

FG3X

SB

PC1

28

27

26

25

24

23

22

21

20

19

18

17

0.5Ω

Servo
Signal

2.1V

ST

SP

R2

(12V)

V

M

V

(5V)

CC

HALL 3

13

H3+

14

H3−

NC

VH

16

15

R1

0.1µF

16

Rev. 1.0.1
Oct. 2000.

FAN8423D3

Rev. 1.0.1
Oct. 2000.

17

FAN8423D3

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

 2000 Fairchild Semiconductor International

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