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FAN8725 (KA3025)
Spindle Motor and 5-Channel Motor Driver
Features
Common
* * * * Built-in thermal shutdown circuit (TSD) Built-in power save circuit 3 Independent voltage source Corresponds to 3.3V or 5V DSP
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.
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
48-QFPH-1414
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
* * * * * * 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
Ordering Information
Device FAN8725 Package 48-QFPH-1414 Operating Temp. -35C ~ +85C
Rev. 1.0.1 March. 2000.
(c)2000 Fairchild Semiconductor International
1
FAN8725 (KA3025)
Pin Assignments
PGND3 37 SVCC2 OUT5 VREF ECR VM3 PC1
48
47
46
45
44
43
42
41
40
39
38
H1+
IN5
VH
EC
PS
SB
1
36
DO5 -
H1H2+
2
35
DO5+ DO4 -
3
34
H2-
4
32
DO4+
H3+ H3-
5
32
DO3 DO3+
6
31
FAN8725
FG 7 30 PGND2
DIR SVCC1
8
29
DO2 DO2+
9
28
VM1
10 11
27
DO1 -
CS1 PGND1
26
DO1+ OUT1
12
25
13 A1
14 A2
15 A3
16 SGND2
17 IN4
18 OUT4
19 IN3
20 OUT3
21 IN2
22 OUT2
23 VM2
24 IN1
2
FAN8725 (KA3025)
Pin Definitions
Pin Number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 Pin Name H1H1+ H2+ H2H3+ H3FG DIR SVCC1 VM1 CS1 PGND1 A1 A2 A3 SGND2 IN4 OUT4 IN3 OUT3 IN2 OUT2 VM2 IN1 OUT1 DO1+ DO1 DO2+ DO2 PGND2 DO3+ DO3 DO4+ I/O I I I I I I O O I O O O I O I O I O I O O O O O O O O Hall 1(-) input Hall 1(+) input Hall 2(-) input Hall 2(+) input Hall 3(-) input Hall 3(+) input Frequency Generator output Rotation direction output Spindle Signal supply voltage Spindle power supply Spindle current sense Spindle power ground 3-phase output1 3-phase output2 3-phase output3 CH signal ground OP-Amp CH 4 input(-) OP-Amp CH 4 output OP-Amp CH 3 input(-) OP-Amp CH 3 output OP-Amp CH 2 input(-) OP-Amp CH 2 output CH1/CH2 power supply OP-Amp CH 1 input(-) OP-Amp CH 1 output Channel 1 output (+) Channel 1 output (-) Channel 2 output (+) Channel 2 output (-) CH1/CH2 power ground Channel 3 output (+) Channel 3 output (-) Channel 4 output (+) Pin Function Description
3
FAN8725 (KA3025)
Pin Definitions (Continued)
Pin Number 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Pin Name DO4 DO5+ DO5PGND3 IN5 OUT5 VM3 SVCC2 VREF SB PS ECR EC PC1 VH I/O O O O I O I I I I I I Pin Function Description Channel 4 output (-) Channel 5 output (+) Channel 5 output (-) CH3/CH4/CH5 power ground OP-Amp CH 5 input(-) OP-Amp CH 5 output CH3/CH4/CH5 power supply CH Signal supply voltage BTL reference voltage Short brake Power save Torque control reference Torque control Phase compensation capacitor 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)
Internal Block Diagram
FIN(GND)
48 Hall Bias
47
46
45
44
43
42
41
40
39
38
IN5
37
PGND3
SVCC2
VREF
ECR
PC1
PS
OUT5
VM3
VH
EC
SB
H1+ H1 H2+ H2 H3+ H3 -
1 2 3 4 5 6
CH5 X8 Hall Amp
Absolute Values
Current Sense Amp Output Current Limit CS1
36 35 34 33 32 31
VM3
DO5 DO5+ DO4 DO4+ DO3 DO3+
CH4 X8
VM
CH3 X8
VM3
R R
FG Generator
Detection Logic
VM2
VM3
FIN(GND)
FIN(GND)
R
VM2
R
FG DIR
7 8 9 Distributor 10 11 12 Driver 13 A1 14 A2 15 A3
Reverse Rotation Short Brake
VM2
30 PGND2
CH2 X5
29 28
DO2 DO2+ DO1 DO1+ OUT1
SVCC1 VM1 CS1 PGND1
CH1 X5
27 26 25
16 SGND2
17 IN4
18 OUT4 FIN(GND)
19 IN3
20 OUT3
21 IN2
22 OUT2
23 VM2
24 IN1
5
FAN8725 (KA3025)
Equivalent Circuits (Spindle Part)
HALL INPUT DRIVER OUTPUT
Pin 10
Pin 11
22.5 Pin 1,3,5
1K
1K
22.5 15K Pin 2,4,6 Pin 13,14,15
TORQUE CONTROL INPUT
HALL BIAS INPUT
22.5
1K
5
Pin 45
22.5 Pin 46 1K
+ -
Pin 48
100K
POWER SAVE INPUT
SHORT BRAKE INPUT
22.5 Pin 44
40K Pin 43 30K
22.5
1K
20K
FG OUTPUT
DIR OUTPUT
Vcc
Vcc
10K 22.5 Pin 7
30K 22.5 Pin 8
6
FAN8725 (KA3025)
Equivalent Circuits (BTL Part)
OP-AMP INPUT OP-AMP OUTPUT
20K Pin 24,21, 19,17,38
20K Pin 25,22,20,18,39
22.5
1K
DRIVE OUTPUT
VREF
40k
20k
CH-O (Pin 26,28,31,33,35 ) 20K Pin 42 CH-O (Pin 27,29,32,34,36) 22.5 1K 20K
20k
7
FAN8725 (KA3025)
Absolute Maximum Ratings (Ta = 25C)
Parameter Supply Voltage (Spindle Signal) Supply Voltage (BTL Signal) Supply Voltage (Spindle Motor) Supply Voltage (BTL CH1/2) Supply Voltage (BTL CH3/4/5) Power dissipation Operating Temperature Range Storage temperature Range Maximum Output Current (Spindle) Maximum Output Current (BTL) Symbol SVCC1max SVCC2max VM1max VM2max VM3max PD TOPR TSTG IOmaxa IOmaxb Value 7 15 15 15 15 3.0
note
Unit V V V V V W C C A A
-35 ~ +85 -55 ~ +150 1.3 0.6
NOTE: 1. When mounted on 70mm x 70mm x 1.6mm PCB (Phenolic resin material) 2. Power dissipation is reduced 24mW/C for using above Ta=25C 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 = 25C)
Parameter Operating Supply Voltage (Spindle Signal) Operating Supply Voltage (BTL Signal) Operating Supply Voltage (Spindle Motor) Operating Supply Voltage (BTL CH1/2) Operating Supply Voltage (BTL CH3/4/5) Symbol SVCC1 SVCC2 VM1 VM2 VM3 Min. 4.5 10.8 10.8 4.5 4.5 Typ. - - - - - Max. 5.5 13.2 13.2 SVCC2 SVCC2 Unit V V V V V
8
FAN8725 (KA3025)
Electrical Characteristics (Ta = 25C)
Parameter FULL CHIP Quiescent Circuit Current 1 Quiescent Circuit Current 2 Quiescent Circuit Current 3 POWER SAVE On Voltage Range Off Voltage Range HALL BIAS Hall Bias Voltage HALL AMP Hall Bias Current Common Mode Input Range Minimum in Level H1 Hysteresis TORQUE CONTROL Ecr In Voltage Range Ec In Voltage Range Offset Voltage (-) Offset Voltage (+) EC In Current ECR In Current In/output Gain FG FG Output Voltage (H) FG Output Voltage (L) Duty(Reference Value) OUTPUT BLOCK Saturation Voltage (upper TR) Saturation Voltage (lower TR) Torque Limit Current DIRECTION DETECTOR DIR Output Voltage (H) Dir Output Voltage (L) SHORT BRAKE On Voltage Range Off Voltage Range VSBon VSBoff 2.5 0 - - VCC 1.0 V V VDIRh VDIRl IFG=-10uA IFG=10uA 4.5 - 4.7 - 0.5 V V VOh VOl ITL IO= -300mA IO=300mA RCS=0.5 - - 560 1.0 0.4 700 1.4 0.7 840 V V mA VFGh VFHl IFG= -10uA IFG=10uA RCS=0.5 4.5 - 4.9 - 50 VCC 0.5 V V % ECR EC ECoffECoff+ ECin ECRin GEC EC =1.9V ECR =1.9V EC=1.9V ECR=1.9V ECR=2.5V, RCS=0.5 0.2 0.2 -80 20 -3 -3 0.56 - - -50 50 -0.5 -0.5 0.70 4.0 4.0 -20 80 - - 0.84 V V mV mV uA uA A/V IHA VHAR VINH VHYS - 1.5 100 5 0.5 - - 20 2 4.0 - 40 uA V mVpp mVpp VHB IHB=20mA 0.4 1.0 1.8 V VPSon VPSoff L-H Circuit On H-L Circuit Off 2.5 - - - Vcc 1.0 V V ICC1 ICC2 ICC3 FULL CHIP (PS=0V) SPINDLE BTL (PS=5V) ( PS=5V) - - - 0 5 20 0.2 10 30 mA mA mA Symbol Condition Min. Typ. Max. Units
9
FAN8725 (KA3025)
ELECTRICAL CHARACTERISTICS (continued)
BTL Drive Part (Ta=25C, SVCC2=12V, VM2=5V, VM3=12V, RL=8, 24) Parameter CH1/CH2 Output Offset Voltage1,2 Maximum Output Voltage1,2 Voltage Gain CH3/CH4/CH5 Output Offset Voltage3,4,5 Maximum Output Voltage3,4,5 Voltage Gain OP-AMP CIRCUIT Common Mode Input Range Input Bias Current Low Level Output Voltage High Level Output Voltage Output Driving Source Current Output Driving Sink Current VICM B VCL VOH ISOURCE ISINK 0 -300 10.0 1 5 - -30 0.2 11 4.0 10 0.5 - - - 11.0 V nA V V mA mA VOF3/4/5 VOM3/4/5 GVC3/4/5 VM3=12V,RL=24 VIN=0.1Vrms, 1kHz -95 8.4 16.0 - 10.5 18.0 95 - 20.0 mV V dB VOF1/2 VOM1/2 GVC1/2 VM2=5V,RL=8 VIN=0.1Vrms, 1kHz -95 3.6 12.0 - 4.0 14.0 95 - 16.0 mV V dB Symbol Condition Min. Typ. Max. Units
10
FAN8725 (KA3025)
Application Information
1. TORQUE CONTROL & OUTPUT CURRENT CONTROL
VM + VM + Torque AMP Ecr + VAMP +
ECR-EC
Vcs Current Sense AMP Gain Controller TSD
Rcs
Io Driver
-
M
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] 700 Ecoff- Ecoff+ Reverse Forward ECR > Ec ECR < Ec Rotation Forward rotation Stop after detecting reverse rotation
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[] )
11
FAN8725 (KA3025)
2. SHORT BRAKE
MOTOR Vcc OFF
ON OFF
43
13 1K ON 20K 14 15
Pin # 43 HIGH LOW
Short Brake ON 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 Stop 30K 44 40K
Pin # 44 HIGH LOW
Power Save Motor Drive Ouput Activated 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-
+ D
DIR 8 Q
Rotation Forward Reverse
8
DIR
Low High
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 H1H2H3 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
+ -
Current Sense Amp
H2+ H2-
+ A D CK D-F/F Q
Low Active
H3+ H3-
+ -
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, 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
Rotation Forward Reverse 7. FG OUTPUT
H2 H L
H3 HL HL
D-F/F (Q) H L
Reverse Rotation Preventer ECR>EC Forward EC>ECR Brake and Stop
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
25K 25K (40K) (40K)
10K
23 40 VM2 (VM3)
R R
10K
10K
10K
- VM2 (VM3) Error Amp
* * * *
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 x (25K / 10K) , the output signal of the error amp is amplified by (R2 / R1) x 5. * Since the differential gain of the output amplifiers of CH3/CH4/CH5 is equal to 2 x (40K / 10K) , the output signal of the error amp is amplified by (R2 / R1) x 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.
+
42 Vref
-
17 19 21 24 38
18
-
+
-
-
25K (40K)
- +
27 29 32 34 36 DO
M
DO+ 26 28 31 33 35
Power amp +
25K (40K)
+
18 20 22 24 39
R2
R1
FAN8725 (KA3025)
Typical Application Circuits
SLED2 SIGNAL SERVO SIGNAL SHORT BRAKE
SVCC2 VM3
POWER SAVE PGND3 48 47 PC1 46 EC 45 ECR 44 PS 43 SB 42 VREF 41 SVCC2 40 VM3 39 OUT5 38 IN5 37 DO5 - 36 DO5+ 35 DO4 - 34 DO4+ 33 DO3 - 32 SLED (stepping) MOTOR
1 HALL1 2 3 HALL2 4 5 HALL3 6
VH
H1+ H1 H2+ H2 H3+ H3 -
M
M
DO3+ 31
LOADING MOTOR
FAN8725
7 8 9 FG DIR SVCC1 PGND2 30 DO2 - 29 DO2+ 28 DO1 - 27 DO1+ 26 SGND2 OUT4 OUT3 OUT2 OUT1 VM2 25 24 IN1 TRACKING ACTUATOR SVCC 1 10 VM1 11 CS1 IN4 IN3 IN2 VM1 12 PGND1 A1 13
FOCUS ACTUATOR
A2 14
15
A3
16
17
18
19
20
21
22
23 VM2
SLED1 SIGNAL
LOADING SIGNAL
TRACKING SIGNAL
FOCUS SIGNAL
19
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. LIFE SUPPORT POLICY FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES 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 instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user.
www.fairchildsemi.com 12/1/00 0.0m 001 Stock#DSxxxxxxxx 2000 Fairchild Semiconductor International
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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