FAN8725 Fairchild Semiconductor, FAN8725 Datasheet
FAN8725
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FAN8725 Summary of contents
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... Other compact disk media ©2000 Fairchild Semiconductor International www.fairchildsemi.com 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. ...
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... FAN8725 (KA3025) Pin Assignments H1 H1- H2 H3+ H3 DIR 8 SVCC1 9 VM1 10 11 CS1 PGND1 FAN8725 DO5 - 35 DO5+ DO4 - 34 DO4 DO3 - 31 DO3+ 30 PGND2 29 DO2 - DO2+ 28 DO1 - 27 26 DO1+ OUT1 ...
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... OP-Amp CH 4 output I OP-Amp CH 3 input(-) O OP-Amp CH 3 output I OP-Amp CH 2 input(-) O OP-Amp CH 2 output - CH1/CH2 power supply I OP-Amp CH 1 input(-) O OP-Amp CH 1 output O Channel 1 output ( O Channel 1 output ( O Channel 2 output ( O Channel 2 output ( - CH1/CH2 power ground O Channel 3 output ( O Channel 3 output ( O Channel 4 output ( 3 FAN8725 (KA3025) ...
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... FAN8725 (KA3025) Pin Definitions (Continued) Pin Number Pin Name 34 DO4 - 35 DO5+ 36 DO5- 37 PGND3 38 IN5 39 OUT5 40 VM3 41 SVCC2 42 VREF ECR PC1 48 VH 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) ...
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... Distributor 10 VM1 11 CS1 PGND1 12 Driver Absolute Values Current Sense Amp Output Current Limit R VM3 Detection R Logic R VM2 R Reverse Rotation Short Brake FAN8725 (KA3025 CH5 CH4 CH3 X8 31 VM3 VM3 FIN(GND) VM2 VM2 PGND2 30 CH2 29 DO2 - X5 28 DO2+ CH1 27 DO1 - X5 26 DO1+ ...
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... FAN8725 (KA3025) Equivalent Circuits (Spindle Part) HALL INPUT 1K 1K 22.5 Pin 1,3,5 TORQUE CONTROL INPUT 22.5 1K Pin 45 1K 22.5 Pin 46 POWER SAVE INPUT 22.5 40K Pin 44 30K FG OUTPUT Vcc 10K 22.5 Pin 22.5 15K Pin 2,4 Pin 48 - Pin 43 Pin 7 6 DRIVER OUTPUT ...
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... Equivalent Circuits (BTL Part) OP-AMP INPUT 20K Pin 24,21, 22.5 1K 19,17,38 DRIVE OUTPUT 20k 40k 20k 20K CH-O (Pin 26,28,31,33,35 ) Pin 42 CH-O (Pin 27,29,32,34,36) 7 FAN8725 (KA3025) OP-AMP OUTPUT Pin 25,22,20,18,39 VREF 20K 20K 22.5 1K ...
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... FAN8725 (KA3025) Absolute Maximum Ratings ( 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) NOTE: 1 ...
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... FGh V I =10uA FG FHl R =0 -300mA =300mA =0 =-10uA FG DIRh V I =10uA FG DIRl V - SBon V - SBoff 9 FAN8725 (KA3025) Min. Typ. Max. Units – 0 0.2 mA – – 2.5 – Vcc V – – 1.0 V 0.4 1.0 1.8 V – 0 1.5 – 4.0 V 100 – – mVpp ...
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... FAN8725 (KA3025) ELECTRICAL CHARACTERISTICS (continued) BTL Drive Part (Ta= =12V, V CC2 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 ...
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... CR Current Sense AMP V AMP - - + ECR-EC ) through the sense resistor ( Forward 50mV FAN8725 (KA3025 Rcs Vcs - Io Gain Driver M Controller TSD ) and compared with the The output current (I AMP ) of the Driver. O Rotation E > Ec Forward rotation CR E < Ec Stop after detecting re- ...
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... 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 make the rotating velocity of the motor slow down. But FG and DIR functions continue to operate normally ...
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... 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 with a 120 phase difference Vcc Rotation DIR Forward 8 Q Reverse 13 FAN8725 (KA3025) 8 DIR Low High (a) Reverse rotation ...
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... FAN8725 (KA3025) On the other hand, if the spindle rotates in forward rotation, the phase relationship is H3->H2->H1 as shown in Fig.( The direction output ,detector is Low, when the spindle rotates forward, and HIGH in the reverse direction. 6. REVERSE ROTATION PREVENTION EC + ECR - H2 H3- D-F/F 1) When the output of the OR Gate LOW, it steers all the output current of the current sense Amp to the Gain Controller zero ...
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... HALL SENSOR CONNECTION HALL 1 Forward rotation at EC < ECR Rotating reverse at short time due to motor inertia Stop within 1/6 turn reverse rotating D-F Vcc 7 FG Vcc HALL 2 HALL FAN8725 (KA3025) Reverse Rotation Preventer E >E E > Forward - - Brake and Stop Vcc HALL 1 HALL 2 HALL ...
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... FAN8725 (KA3025) 9. CONNECT A BYPASS CAPACITOR, FROM ALL THE SUPPLY VOLTAGE SOURCES TO GROUND. (Typically 0.1uF, or even higher) 10. THE HEAT RADIATION FIN IS CONNECTED TO THE INTERNAL GND OF THE PACKAGE. Connect the FIN to the external GND. SVcc1, SVcc2 0.1uF 16 ...
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... INPUT-OUTPUT TIMING CHART output current (H1 -)+( output voltage A2 output current (H2 -)+( output voltage A3 output current (H3 -)+( output voltage 17 FAN8725 (KA3025) ...
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... FAN8725 (KA3025) 12. BTL DRIVE PART VM2 (VM3) VM2 R (VM3) • The reference voltage REF is given externally through pin 42. • The error amp output signal is amplified 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. ...
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... VM1 11 CS1 PGND1 VM1 SERVO SHORT SIGNAL BRAKE SVCC2 VM3 POWER SAVE FAN8725 SLED1 LOADING SIGNAL SIGNAL 19 FAN8725 (KA3025) SLED2 SIGNAL DO5 - 36 DO5+ 35 SLED M (stepping) MOTOR DO4 - 34 DO4+ 33 DO3 - 32 LOADING M MOTOR DO3 PGND2 DO2 - 29 TRACKING ACTUATOR DO2 DO1 - FOCUS ACTUATOR ...
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... 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. ...