www.fairchildsemi.com FAN8420D (KA3020D); Preliminary 3-Phase BLDC Motor Driver Features Description • • • • • • • • • • The FAN8420D is a monolithic IC, suitable for a 3-phase spindle motor driver of a CD-media system. 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 3.3V DSP 28-SSOPH-375 Typical Applications • • • • • • • Ordering Information 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 Device Package Operating Temp. FAN8420D 28-SSOPH-375 −25°C ~ +75°C FAN8420DTF 28-SSOPH-375 −25°C ~ +75°C Rev. .9.0 February. 2000. ©2000 Fairchild Semiconductor International 1 FAN8420D (KA3020D); PRELIMINARY SB PC1 NC VH 21 20 19 18 17 16 15 8 9 10 11 12 13 14 H2− H3+ H3− 22 H2+ EC 23 FG3X S/S 24 H1− FG1X 25 DIR VCC 26 H1+ NC 27 ECR VM 28 FIN(GND) GND CS1 Pin Assignments 1 2 3 4 5 6 7 NC A3 NC A2 NC NC A1 FAN8420D FIN(GND) Pin Definitions Pin 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 2 FAN8420D (KA3020D); PRELIMINARY Pin Definitions (Continued) Pin Number Pin Name I/O Pin Function Description 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 − PC1 NC VH 21 20 19 18 17 16 15 Current sense Amp Output Current limit Logic Absolute Values Reverse rotation Start Stop + Hall 22 SB EC 23 Short Brake S/S 24 FG3X FG1X 25 FG3X Generator VCC 26 DIR NC 27 GND ECR VM 28 FG1X Generator CS1 Internal Block Diagram A3 NC A2 NC NC A1 GND 3 Detection 8 9 10 11 12 13 14 H3− 7 H3+ 6 H2− 5 H2+ 4 H1− 3 H1+ 2 Hall amp GND 1 NC Lower Distributor Commutation Selector Upper Distributor Detector TSD FAN8420D (KA3020D); PRELIMINARY Equivalent Circuits Hall input Driver output 27 9 28 10 1kΩ 1kΩ 50Ω 50Ω 11 12 13 14 2 Torque control input 7 Hall bias input 50Ω 5Ω + 21 4 15 50Ω − 22 100kΩ Start / Stop input 50Ω Short brake input 50Ω 40kΩ 23 1kΩ 18 30kΩ 20kΩ FG output Dir output VCC VCC 10kΩ 30kΩ 50Ω 50Ω 19 24 20 4 FAN8420D (KA3020D); PRELIMINARY Absolute Maximum Ratings (Ta = 25°C) Parameter Symbol Value Unit Maximum supply voltage (Signal) VCCmax 7 V Maximum supply voltage (Motor) VMmax 15 V PD 1.7note W Operating temperature range TOPR −25 ~ +75 °C Storage temperature range TSTG −55 ~ +150 °C Power dissipation NOTE: 1. When mounted on a 50mm × 50mm × 1mm PCB (Phenolic resin material). 2. Power dissipation reduces 13.6mW / °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 SOA 0 25 50 75 100 125 150 175 Ambient temperature, Ta [°C] Recommended Operating Conditions (Ta = 25°C) Parameter Symbol Min. Supply voltage VCC Motor supply voltage VM 5 Typ. Max. Unit 4.5 5 5.5 V 3.0 12 14 V FAN8420D (KA3020D); PRELIMINARY Electrical Characteristics (Unless otherwise specified, Ta=25°C, VCC=5V, VM=12V) Parameter Symbol Conditions Min. Typ. Max. Unit Quiescent circuit current 1 ICC1 At stop mode - - 0.2 mA Quiescent circuit current 2 ICC2 At start mode - 5 10 mA START / STOP On voltage range VSSon Output driver on 2.5 - VCC V Off voltage range VSSoff Output driver off 0.0 - 1.0 V VHB IHB=20mA 0.4 1.0 1.8 V IHA - - 0.5 2 µA Common-mode input range VHAR - 1.5 - 4.0 V Minimum input level VINH - 60 - - mVpp H1 hysteresis level VHYS - 5 20 40 mVpp Ecr Input voltage range ECR - 0.2 - 3.3 V Ec Input voltage range EC - 0.2 - 3.3 V HALL BIAS Hall bias voltage HALL AMP Hall bias current TORQUE CONTROL Offset voltage (−) ECoff− EC=1.9V −80 −50 −20 mV Offset voltage (+) ECoff+ EC=1.9V 20 50 80 mV Ec Input current ECin EC=1.9V - 0.3 3 µA Ecr Input current ECRin ECR=1.9V - 0.3 3 µA Input / output gain GEC EC=1.9V, RCS=0.5Ω - 0.71 - A/V FG output voltage (H) VFGh Ifg=-10µA 4.5 4.9 - V FG output voltage (L) VFGl Ifg=10µA - - 0.5 V Duty (reference value) - - 50 - % FG - OUTPUT BLOCK Saturation voltage (upper TR) VOH IO=−300mA - 0.9 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=-10µA 4.5 4.7 - V Dir output voltage (L) VDIRl Ifg=10µA - - 0.5 V DIRECTION DETECTOR SHORT BRAKE On voltage range VSBon - 2.5 - VCC V Off voltage range VSBoff - 0 - 1.0 V 6 FAN8420D (KA3020D); PRELIMINARY Electrical Characteristics (Continued) CALCULATION OF GAIN & TORQUE LIMIT CURRENT VM VM IO Current / Voltage Convertor − Negative Feedback loop Vin EC ECR + − − Output V S RS Current sense + CS1 (Pin 28) R1 U V − + + Gm Driver Power Transistors W + Absolute Values Commutation Distributor + Vmax − H1 VM Max. output current limiting 0.355 is GM times R1 and is a fixed value within IC. 0.355 Gain = --------------- [ A ⁄ V ] RS Vmax (see above block diagram) is set at 350mV. 350 [ mV ] Vmax Itl = ---------------- = -----------------------RS RS 7 H2 H3 IO FAN8420D (KA3020D); PRELIMINARY Application Information 1. TORQUE CONTROL & OUTPUT CURRENT CONTROL VM + Current Sense AMP Torque AMP ECR + + − RCS VCS − VM − IO Gain Controller ECR-EC Driver M TSD EC • By amplifying the voltage difference between EC and Ecr from servo IC, the torque sense amp produces the input (VAMP) for the current sense amp. • 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. Therefore, the output current (IO) is linearly controlled by the input VAMP. • As a result, the signals, EC and ECR can control the velocity of the Motor by controlling the output current (IO) of the driver. • The range of the torque voltage is as shown below. Current [mA] Forward Reverse Rotation 700 500 Ecoff- Ecoff+ ECR > Ec Forward rotation ECR < Ec Stop after detecting reverse rotation 0.71[A/V] 6 -50m V 0 50m V ECR -EC The input range of ECR and EC is 0.2 V ~ 3.3 V ( RNF = 0.5[Ω] ) 8 FAN8420D (KA3020D); PRELIMINARY 2. SHORT BRAKE MOTOR OFF VCC 18 ON 2 4 1kΩ 7 OFF ON 20kΩ 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, the brake function of the reverse voltage 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 FAN8420D. When the short brake function is active, all upper power TRs turn off and all lower power TRs turn on, and the motor slows down. But FG and DIR functions continue to operate normally. 3. POWER SAVE MOTOR OFF VCC Start 23 2 4 40kΩ 7 OFF Stop 30kΩ Pin # 23 Start/Stop High Operate Low Stop When power save function is active, all power TRs turn off. 9 FAN8420D (KA3020D); PRELIMINARY 4. TSD (THERMAL SHUTDOWN) Gain Controller BIAS Q2 When the chip temperature rises above 175°C, the Q2 turns on and the output driver shuts down. When the chip temperature falls off to about 150°C, then the Q2 turns off and the driver operates normally. TSD has the temperature hysteresis of about 25°C. 5. ROTATIONAL DIRECTION DETECTION VCC H2+ + H2− − DIR 20 D Q Rotation 20 DIR Forward Low Reverse High CK H3+ + H3− − D-F/F • The forward and the reverse rotations of the CD are detected by the D-F/F and the truth table is shown in the above. • The rotational direction of the CD can be explained by the output waveforms of the Hall sensors. The three outputs of Hall sensors be H1, H2 and H3 respectively. When the spindle rotates in reverse direction, the Hall sensor output waveforms are shown in Fig.(a). The phases order are in H1→H2→H3 with a 120°C 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 shown in fig.(b) 10 FAN8420D (KA3020D); PRELIMINARY H1 H2 H3 (b) Forward rotation Therefore, the output of the rotational direction detector is low, when the spindle rotates forward, and high in the reverse rotation. 6. REVERSE ROTATION PREVENTION EC + ECR − H2+ + H2− − H3+ + H3− − Current Sense Amp Low Active A Q D CK Gain Controller D-F/F Driver M • 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. • 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. Rotation H2 H3 D-F/F(Q) Forward H H→L Reverse L H→L 11 Reverse rotation preventer EC<ECR EC>ECR H Forward - L - Brake and stop FAN8420D (KA3020D); PRELIMINARY 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 OUT H1− H1+ 24 FG1X H2− 19 FG3X H2+ H3− H3+ 8. HALL SENSOR CONNECTION VCC VCC HALL 1 HALL 1 HALL 2 HALL 3 HALL 2 HALL 3 15 VH 15 VH 12 FAN8420D (KA3020D); PRELIMINARY 9. Connect a by-pass capacitor, 0.1µF between the supply voltage source Vcc 25 0.1µF 10. The heat radiation fin is connected to the internal GND of the package. Connect that fin to the external GND. 13 FAN8420D (KA3020D); PRELIMINARY 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 14 FAN8420D (KA3020D); PRELIMINARY Test Circuits 10µA 20mA V VM5 14 V VM3 13 5V 12V VR1 IM3 A IM2 A 10µA VR5 VR3 VR2 10µA 15 15 IM1 A IM2 A RCS 0.5Ω VM7 V V VM4 VM6 VM6 0.1µF 28 27 26 25 24 23 CS1 VM NC VCC FG1X 22 SS EC 21 20 ECR DIR 19 18 17 16 15 FG3X SB PC1 NC VH FAN8420D NC A3 NC A2 NC NC A1 GND H1+ H1− H2+ H2− H3+ H3− 1 2 3 4 5 6 7 8 9 10 11 12 13 14 IM4 VM8 V c a b SW3 SW2 SW1 c a V c A V b b RL=5Ω a RL=5Ω RL=5Ω SW13 a V b VM1 V VM2 12V 300mA 300mA 15 VR8 VR9 IM5 A IM6 A IM7 A IM8 A VR10 VR11 VR12 VR13 IM9 A FAN8420D (KA3020D); PRELIMINARY Typical Application Circuits 0.5Ω 1 NC CS1 28 2 A3 VM 27 3 NC NC 26 4 A2 VCC 25 5 NC FG1X 24 6 NC SS 23 7 A1 EC 22 VM (12V) VCC (5V) ST SP 1.675V FAN8420D 8 GND ECR 21 9 H1+ DIR 20 10 H1− FG3X 19 11 H2+ SB 18 12 H2− PC1 17 13 H3+ NC 16 14 H3− VH 15 Servo Signal HALL 1 HALL 2 R2 0.1µF HALL 3 R1 16 28-SSOPH-375 MIN 0.05 0.002 2.20 ±0.20 0.087 ±0.008 #28 #14 #15 2.50 MAX 0.098 8° MAX0.10 MAX0.004 7.50 ±0.20 0.295 ±0.008 0~ +0.10 0.25 -0.05 +0.004 0.010 -0.002 0.80 ±0.20 0.031 ±0.008 0.40 ±0.10 0.016 ±0.004 0.80 0.031 10.00 ±0.30 0.394 ±0.012 9.53 0.375 18.40 ±0.20 0.724 ±0.008 18.80 MAX 0.740 ( 1.20 ) 0.047 #1 TRADEMARKS The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. 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A critical component is any component of a life support device or system whose failure to perform can systems which, (a) are intended for surgical implant into be reasonably expected to cause the failure of the life the body, or (b) support or sustain life, or (c) whose support device or system, or to affect its safety or failure to perform when properly used in accordance with instructions for use provided in the labeling, can be effectiveness. reasonably expected to result in significant injury to the user. PRODUCT STATUS DEFINITIONS Definition of Terms Datasheet Identification Product Status Definition Advance Information Formative or In Design This datasheet contains the design specifications for product development. Specifications may change in any manner without notice. Preliminary First Production This datasheet contains preliminary data, and supplementary data will be published at a later date. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. No Identification Needed Full Production This datasheet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice in order to improve design. Obsolete Not In Production This datasheet contains specifications on a product that has been discontinued by Fairchild semiconductor. The datasheet is printed for reference information only. Rev. F1