FAIRCHILD FAN8725

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FAN8725 (KA3025)
Spindle Motor and 5-Channel Motor Driver
Features
Description
Common
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.
•
•
•
•
Built-in thermal shutdown circuit (TSD)
Built-in power save circuit
3 Independent voltage source
Corresponds to 3.3V or 5V DSP
Spindle
•
•
•
•
•
48-QFPH-1414
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
Typical Applications
•
•
•
•
•
•
Ordering Information
Compact disk ROM (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
Device
Package
Operating Temp.
FAN8725
48-QFPH-1414
−35°C ~ +85°C
Rev. 1.0.1
March. 2000.
©2000 Fairchild Semiconductor International
1
FAN8725 (KA3025)
VH
PC1
EC
ECR
PS
SB
VREF
SVCC2
VM3
OUT5
IN5
PGND3
Pin Assignments
48
47
46
45
44
43
42
41
40
39
38
37
H1+
1
36
DO5 -
H1-
2
35
DO5+
H2+
3
34
DO4 -
H2-
4
32
DO4+
H3+
5
32
DO3 -
H3-
6
31
DO3+
FAN8725
VM1
10
27
DO1 -
CS1
11
26
DO1+
PGND1
12
25
OUT1
13
14
15
16
17
18
2
19
20
21
22
23
24
IN1
DO2+
VM2
28
OUT2
9
IN2
SVCC1
OUT3
DO2 -
IN3
29
OUT4
8
IN4
DIR
SGND2
PGND2
A3
30
A2
7
A1
FG
FAN8725 (KA3025)
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 (+)
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
FAN8725 (KA3025)
2
H2+
3
H2 -
4
H3+
5
H3 -
6
OUT5
IN5
PGND3
SB
VM3
PS
43
SVCC2
ECR
44
VREF
EC
45
FIN(GND)
PC1
46
42
41
40
39
38
37
Hall
Bias
CH5
X8
Absolute Values
CH4
X8
Current
Sense Amp
CS1
H1 -
47
Output
Current Limit
CH3
X8
DO5 -
35
DO5+
34
DO4 -
33
DO4+
32
DO3 -
31
DO3+
R
VM3
VM3
R
Detection
FG
Generator
FIN(GND)
36
VM
1
48
Hall Amp
H1+
VH
Internal Block Diagram
VM3
FIN(GND)
Logic
R
VM2
FG
7
Reverse
Rotation
DIR
8
Short
Brake
SVCC1
9
VM1
10
CS1
PGND1
VM2
VM2
R
30 PGND2
CH2
X5
29
DO2 -
28
DO2+
27
DO1 -
11
26
DO1+
12
25
OUT1
Distributor
CH1
X5
5
A3
SGND2
IN4
OUT4
20
21
22
23
24
IN1
A2
19
VM2
18
OUT2
17
IN2
16
OUT3
15
IN3
14
FIN(GND)
13
A1
Driver
FAN8725 (KA3025)
Equivalent Circuits (Spindle Part)
HALL INPUT
DRIVER OUTPUT
Pin 10
1KΩ
22.5Ω
1KΩ
Pin 11
22.5Ω
15KΩ
Pin
2,4,6
Pin
1,3,5
Pin 13,14,15
TORQUE CONTROL INPUT
22.5Ω
HALL BIAS INPUT
1KΩ
5Ω
+
Pin 45
Pin 48
1KΩ
22.5Ω
-
Pin 46
100KΩ
POWER SAVE INPUT
22.5Ω
SHORT BRAKE INPUT
22.5Ω
40KΩ
1KΩ
Pin 43
Pin 44
30KΩ
20KΩ
FG OUTPUT
DIR OUTPUT
Vcc
Vcc
10KΩ
30KΩ
22.5Ω
22.5Ω
Pin 8
Pin 7
6
FAN8725 (KA3025)
Equivalent Circuits (BTL Part)
OP-AMP INPUT
20KΩ
OP-AMP OUTPUT
20KΩ
Pin
25,22,20,18,39
Pin
24,21,
19,17,38
22.5Ω
1KΩ
DRIVE OUTPUT
40kΩ
20kΩ
VREF
CH-O
(Pin 26,28,31,33,35 )
20KΩ
Pin 42
CH-O
(Pin 27,29,32,34,36)
22.5Ω
20kΩ
7
1KΩ
20KΩ
FAN8725 (KA3025)
Absolute Maximum Ratings (Ta = 25°°C)
Parameter
Symbol
Value
Unit
Supply Voltage (Spindle Signal)
SVCC1max
7
V
Supply Voltage (BTL Signal)
SVCC2max
15
V
Supply Voltage (Spindle Motor)
VM1max
15
V
Supply Voltage (BTL CH1/2)
VM2max
15
V
Supply Voltage (BTL CH3/4/5)
VM3max
15
V
Power dissipation
3.0
PD
note
W
Operating Temperature Range
TOPR
-35 ~ +85
°C
Storage temperature Range
TSTG
-55 ~ +150
°C
Maximum Output Current (Spindle)
IOmaxa
1.3
A
Maximum Output Current (BTL)
IOmaxb
0.6
A
NOTE:
1. When mounted on 70mm × 70mm × 1.6mm PCB (Phenolic resin material)
2. Power dissipation is reduced 24mW/°C for using above Ta=25°C
3. Do not exceed PD and SOA (Safe Operating Area)
Power Dissipation Curve
Pd [mW]
3,000
2,000
1,000
0
0
25
50
85
100
125
150
175
Ambient Temperature, Ta [°C]
Recommended Operating Conditions (Ta = 25°°C)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Operating Supply Voltage (Spindle Signal)
SVCC1
4.5
–
5.5
V
Operating Supply Voltage (BTL Signal)
SVCC2
10.8
–
13.2
V
Operating Supply Voltage (Spindle Motor)
VM1
10.8
–
13.2
V
Operating Supply Voltage (BTL CH1/2)
VM2
4.5
–
SVCC2
V
Operating Supply Voltage (BTL CH3/4/5)
VM3
4.5
–
SVCC2
V
8
FAN8725 (KA3025)
Electrical Characteristics (Ta = 25°°C)
Parameter
Symbol
Condition
Min.
Typ.
Max.
Units
FULL CHIP
Quiescent Circuit Current 1
ICC1
FULL CHIP (PS=0V)
–
0
0.2
mA
Quiescent Circuit Current 2
ICC2
SPINDLE
(PS=5V)
–
5
10
mA
Quiescent Circuit Current 3
ICC3
BTL
( PS=5V)
–
20
30
mA
POWER SAVE
On Voltage Range
VPSon
L-H Circuit On
2.5
–
Vcc
V
Off Voltage Range
VPSoff
H-L Circuit Off
–
–
1.0
V
0.4
1.0
1.8
V
HALL BIAS
Hall Bias Voltage
VHB
IHB=20mA
HALL AMP
IHA
-
–
0.5
2
uA
Common Mode Input Range
Hall Bias Current
VHAR
-
1.5
–
4.0
V
Minimum in Level
VINH
-
100
–
–
mVpp
H1 Hysteresis
VHYS
-
5
20
40
mVpp
Ecr In Voltage Range
ECR
-
0.2
–
4.0
V
Ec In Voltage Range
EC
-
0.2
–
4.0
V
TORQUE CONTROL
Offset Voltage (-)
ECoff-
EC =1.9V
-80
-50
-20
mV
Offset Voltage (+)
ECoff+
ECR =1.9V
20
50
80
mV
-3
-0.5
–
uA
EC In Current
ECin
EC=1.9V
ECR In Current
ECRin
ECR=1.9V
-3
-0.5
–
uA
In/output Gain
GEC
ECR=2.5V, RCS=0.5Ω
0.56
0.70
0.84
A/V
FG Output Voltage (H)
VFGh
IFG= -10uA
4.5
4.9
VCC
V
FG Output Voltage (L)
VFHl
IFG=10uA
–
–
0.5
V
FG
RCS=0.5Ω
Duty(Reference Value)
50
%
OUTPUT BLOCK
Saturation Voltage (upper TR)
VOh
IO= -300mA
–
1.0
1.4
V
Saturation Voltage (lower TR)
VOl
IO=300mA
–
0.4
0.7
V
Torque Limit Current
ITL
RCS=0.5Ω
560
700
840
mA
DIR Output Voltage (H)
VDIRh
IFG=-10uA
4.5
4.7
Dir Output Voltage (L)
VDIRl
IFG=10uA
–
–
0.5
V
DIRECTION DETECTOR
V
SHORT BRAKE
On Voltage Range
VSBon
-
2.5
–
VCC
V
Off Voltage Range
VSBoff
-
0
–
1.0
V
9
FAN8725 (KA3025)
ELECTRICAL CHARACTERISTICS (continued)
BTL Drive Part (Ta=25°°C, SVCC2=12V, VM2=5V, VM3=12V, RL=8, 24Ω
Ω)
Parameter
Symbol
Condition
Min.
Typ.
Max.
Units
Output Offset Voltage1,2
VOF1/2
-
-95
–
95
mV
Maximum Output Voltage1,2
VOM1/2
VM2=5V,RL=8Ω
3.6
4.0
–
V
Voltage Gain
GVC1/2
VIN=0.1Vrms, 1kHz
12.0
14.0
16.0
dB
-95
–
95
mV
CH1/CH2
CH3/CH4/CH5
Output Offset Voltage3,4,5
VOF3/4/5
Maximum Output
Voltage3,4,5
VOM3/4/5
VM3=12V,RL=24Ω
8.4
10.5
–
V
Voltage Gain
GVC3/4/5
VIN=0.1Vrms, 1kHz
16.0
18.0
20.0
dB
11.0
V
-
OP-AMP CIRCUIT
Common Mode Input Range
VICM
-
0
–
ΙB
-
-300
-30
Low Level Output Voltage
VCL
-
-
0.2
0.5
V
High Level Output Voltage
VOH
-
10.0
11
–
V
ISOURCE
-
1
4.0
–
mA
ISINK
-
5
10
–
mA
Input Bias Current
Output Driving Source Current
Output Driving Sink Current
10
nA
FAN8725 (KA3025)
Application Information
1. TORQUE CONTROL & OUTPUT CURRENT CONTROL
VM
+
Rcs
Vcs
VM
+
Ecr
+
Current Sense AMP
VAMP
Torque AMP
Io
+
-
-
Gain
Controller
Driver
M
ECR-EC
TSD
Ec
1) By amplifying the voltage difference between Ec and Ecr from Servo IC, the Torque Sense AMP produces the input voltage(VAMP) for the Current Sense AMP.
2) The output current (IO) is converted into the voltage (VCS) through the sense resistor (RCS) and compared with the VAMP.
By the negative feedback loop, the sensed output voltage, VCS is equal to the input VAMP. The output current (IO) is linearly controlled by the input VAMP.
3) The signals, EC and ECR can control the velocity of the Motor by controlling the output current (IO) of the Driver.
4) The range of the torque voltage is as shown below.
Current
[mA]
Forward
Reverse
Rotation
700
Ecoff- Ecoff+
6
-1.0 V
-50mV
0
50mV
1.0 V
ECR -EC
The input range of ECR, EC is 0.2 V ~ 4.0 V ( RCS = 0.5[Ω] )
11
ECR > Ec
Forward rotation
ECR < Ec
Stop after detecting reverse rotation
FAN8725 (KA3025)
2. SHORT BRAKE
MOTOR
OFF
Vcc
ON
43
13
1KΩ
14
15
OFF
ON
20KΩ
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
IC bias
Start
44
40KΩ
Stop
30KΩ
Pin # 44
Power Save
HIGH
Motor Drive Ouput Activated
LOW
Sleep mode
When PowerSave(PS) function is activated, the chip is deactivated.
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-
-
DIR
Rotation
8
DIR
Forward
Low
Reverse
High
8
D
Q
CK
H3+
+
H3-
-
D-F/F
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 rotational direction of the CD can be explained by the 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 shown 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-
-
Current
Sense
Amp
Low Active
A
D
Q
CK
Gain
Controller
D-F/F
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, becomes 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
Reverse Rotation Preventer
Rotation
H2
H3
D-F/F
(Q)
ECR>EC
EC>ECR
Forward
H
H→L
H
Forward
-
Reverse
L
H→L
L
-
Brake and Stop
7. FG OUTPUT
Vcc
7
H3+
+
H3-
-
FG
8. HALL SENSOR CONNECTION
Vcc
Vcc
HALL 1
HALL 1
HALL 2
HALL 3
HALL 2
HALL 3
48 VH
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, VM3
0.1uF
10. THE HEAT RADIATION FIN IS CONNECTED TO THE INTERNAL GND OF THE PACKAGE.
Connect the FIN to the external GND.
16
FAN8725 (KA3025)
11. 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
17
FAN8725 (KA3025)
12. BTL DRIVE PART
DO+ 26 28 31 33 35
Power amp
10K
10K
10K
−
10K
25K 25K
(40K) (40K)
25K
(40K)
−
+
+
25K
(40K)
+
23 40
VM2
(VM3)
M
−
27 29 32 34 36 DO
R
18 20 22 24 39
−
R
Error
Amp
VM2
(VM3)
+
42
Vref
−
+
R2
−
R1
17 19 21 24 38
•
•
•
•
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
FAN8725 (KA3025)
Typical Application Circuits
SLED2
SIGNAL
SERVO
SIGNAL
SHORT
BRAKE
SVCC2 VM3
47
46
45
44
43
42
41
40
39
38
1
H1+
EC
ECR
PS
SB
VREF
SVCC2
VM3
OUT5
IN5
PGND3
48
PC1
VH
POWER
SAVE
2
H1 -
DO5+ 35
3
H2+
DO4 - 34
4
H2 -
DO4+ 33
5
H3+
DO3 - 32
H3 -
DO3+ 31
HALL1
37
DO5 - 36
M
SLED
(stepping)
MOTOR
M
LOADING
MOTOR
HALL2
HALL3
6
FAN8725
8
DIR
9
PGND2 30
DO2 - 29
SVCC1
10 VM1
DO1 - 27
11 CS1
DO1+ 26
FOCUS
ACTUATOR
A3
SGND2
IN4
OUT4
IN3
OUT3
IN2
OUT2
VM2
IN1
OUT1
13
14
15
16
17
18
19
20
21
22
23
24
12 PGND1
TRACKING
ACTUATOR
DO2+ 28
A2
VM1
FG
A1
SVCC
1
7
25
VM2
SLED1
SIGNAL
LOADING
SIGNAL
19
TRACKING
SIGNAL
FOCUS
SIGNAL
FAN8725 (KA3025)
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD 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 ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
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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
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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