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?2000 fairchild semiconductor international www.fairchildsemi.com rev. .9.0 february. 2000. 1 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 3.3v dsp description the fAN8420D is a monolithic ic, suitable for a 3-phase spindle motor driver of a cd-media system. 28-ssoph-375
fAN8420D (ka3020d); preliminary 2 pin assignments 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 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 fAN8420D nc a3 nc a2 nc a1 nc gnd h1+ h1 - h2+ h2 - h3+ h3 - cs1 vm nc vcc s/s ec fg1x ecr dir fg3x sb pc1 nc vh fin(gnd) fin(gnd)
fAN8420D (ka3020d); preliminary 3 pin definitions (continued) internal block diagram 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 1 2 3 4 5 6 7 8 9 10 11121314 15 16 17 18 19 20 21 22 23 24 25 26 27 28 fg1x generator start stop short brake reverse rotation commutation selector detector detection upper distributor lower distributor hall amp tsd hall absolute values current sense amp output current limit + - nc a3 nc a2 nc nc a1 gnd h1+ h1 - h2+ h2 - h3+ h3 - vh nc sb pc1 fg3x dir ecr ec s/s fg1x vcc nc vm cs1 logic generator fg3x gnd gnd
fAN8420D (ka3020d); preliminary 4 equivalent circuits hall input driver output torque control input hall bias input start / stop input short brake input fg output dir output 1k w 11 9 13 12 14 10 1k w 50 w 50 w 28 2 27 4 7 + - 21 22 50 w 50 w 15 100k w 5 w 23 40k w 30k w 50 w 18 1k w 20k w 50 w 10k w v cc 24 50 w 19 30k w v cc 20 50 w
fAN8420D (ka3020d); preliminary 5 absolute maximum ratings (ta = 25 c) 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 p d and soa (safe operating area). power dissipation curve recommended operating conditions (ta = 25 c) parameter symbol value unit maximum supply volta g e (si g nal) v ccmax 7v maximum supply volta g e (motor) v mmax 15 v power dissipation p d 1.7 note w operatin g temperature ran g et opr - 25 ~ +75 c stora g e temperature ran g et stg - 55 ~ +150 c parameter symbol min. typ. max. unit supply volta g ev cc 4.555.5 v motor supply volta g ev m 3.0 12 14 v 3,000 2,000 1,000 0 0 25 50 75 100 125 150 175 pd (mw) ambient temperature, ta [ c] soa
fAN8420D (ka3020d); preliminary 6 electrical characteristics (unless otherwise specified, ta=25 c, v cc =5v, v m =12v) parameter symbol conditions min. typ. max. unit quiescent circuit current 1 i cc1 at stop mode - - 0.2 ma quiescent circuit current 2 i cc2 at start mode - 5 10 ma start / stop on volta g e ran g ev sson output driver on 2.5 - v cc v off volta g e ran g ev ssoff output driver off 0.0 - 1.0 v hall bias hall bias volta g ev hb i hb =20ma 0.4 1.0 1.8 v hall amp hall bias current i ha --0.52 m a common-mode input ran g ev har - 1.5 - 4.0 v minimum input level v inh -60--mvpp h1 h y steresis level v hys - 5 20 40 mvpp torque control ecr input volta g e ran g ee cr - 0.2 - 3.3 v ec input volta g e ran g ee c - 0.2 - 3.3 v offset volta g e ( - )e coff - e c =1.9v - 80 - 50 - 20 mv offset volta g e (+) e coff+ e c =1.9v 205080mv ec input current e cin e c =1.9v - 0.3 3 m a ecr input current e crin e cr =1.9v - 0.3 3 m a input / output g ain g ec e c =1.9v, r cs =0.5 w - 0.71 - a/v fg fg output volta g e (h) v fgh if g =-10 m a 4.5 4.9 - v fg output volta g e (l) v fgl if g =10 m a - - 0.5 v dut y (reference value) - - - 50 - % output block saturation volta g e (upper tr) v oh i o = - 300ma - 0.9 1.4 v saturation volta g e (lower tr) v ol i o =300ma - 0.4 0.7 v torque limit current i tl r cs =0.5 w 560 700 840 ma direction detector dir output volta g e (h) v dirh if g =-10 m a 4.5 4.7 - v dir output volta g e (l) v dirl if g =10 m a - - 0.5 v short brake on volta g e ran g ev sbon -2.5-v cc v off volta g e ran g ev sboff - 0 - 1.0 v
fAN8420D (ka3020d); preliminary 7 electrical characteristics (continued) calculation of gain & torque limit current 0.355 is gm times r1 and is a fixed value within ic. vmax (see above block diagram) is set at 350mv. ec ecr + - gm - + + absolute values current / voltage convertor r1 vin + - driver vm vmax max. output current limiting + - vm vm negative feedback loop i o r s v s - + cs1 (pin 28) output current sense power transistors commutation distributor u v w h1 h2 h3 i o gain 0.355 r s -------------- - av [] = itl vmax r s --------------- - 350 mv [] r s ------------------------ ==
fAN8420D (ka3020d); preliminary 8 application information 1. torque control & output current control ? by amplifying the voltage difference between e c and ecr from servo ic, the torque sense amp produces the input (v amp ) for the current sense amp. ? the output current (i o ) is converted into the voltage (v cs ) through the sense resistor (r cs ) and compared with the v amp . by the negative feedback loop, the sensed output voltage, v cs is equal to the input v amp . therefore, the output current (i o ) is linearly controlled by the input v amp . ? as a result, the signals, e c and e cr can control the velocity of the motor by controlling the output current (i o ) of the driver. ? the range of the torque voltage is as shown below. + - + - tor q ue a m p e c e cr v m ecr-ec current sense amp tsd gain controller driver m r cs v cs + - i o v m forward ecoff+ ecoff- reverse current [ ma ] 6 0 e cr -e c rotation e cr > ec forward rotation e cr < ec stop after detecting re- verse rotation the input ran g e of e cr and e c is 0.2 v ~ 3.3 v ( r nf = 0.5 [ w ] ) 500 700 50mv -50m v 0.71[a/v]
fAN8420D (ka3020d); preliminary 9 2. short brake 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 when power save function is active, all power trs turn off. pin # 18 short brake high on low off pin # 23 start/stop high operate low stop 2 4 7 18 v cc on off 20k w 1k w motor off on start stop 2 4 7 23 v cc 30k w 40k w motor off off
fAN8420D (ka3020d); preliminary 10 4. tsd (thermal shutdown) 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 ? 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. on the other hand, if the spindle rotates in forward rotation, the phase relationship is h3 ? h2 ? h1 as shown in fig.(b) gain controller bias q2 20 + - + - v cc dir d-f/f d q ck h2+ h3+ h3 - h2 - rotation dir forward low reverse hi g h 20 ( a ) reverse rotation h1 h2 h3
fAN8420D (ka3020d); preliminary 11 therefore, the output of the rotational direction detector is low, when the spindle rotates forward, and high in the reverse ro ta- tion. 6. reverse rotation prevention ? 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) reverse rotation preventer e c e cr forward h h ? lh forward - reverse l h ? l l - brake and stop (b) forward rotation h1 h2 h3 + - + - + - current sense amp gain controller driver d-f/f m d q ck h3+ h3 - h2+ h2 - e c e cr a low active
fAN8420D (ka3020d); preliminary 12 7. fg out 8. hall sensor connection forward rotation at e c < e cr rotating speed is decreased due to reverse torque at e c >e cr . (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 h1 - h1+ h2 - h2+ h3 - h3+ fg1x fg3x 24 19 v cc hall 1 hall 2 hall 3 15 vh v cc hall 1 hall 2 hall 3 15 vh
fAN8420D (ka3020d); preliminary 13 9. connect a by-pass capacitor, 0.1 m f between the supply voltage source 10. the heat radiation fin is connected to the internal gnd of the package. connect that fin to the external gnd. 25 vcc 0.1 m f
fAN8420D (ka3020d); preliminary 14 11. input-output timing chart h1 + h2 + h3 + a1 output current (h1 - )+(h2 +) a3 output current (h3 - )+(h1 +) a3 output voltage a2 output voltage a2 output current (h2 - )+(h3 +) a1 output voltage
fAN8420D (ka3020d); preliminary 15 test circuits 1234567 891011121314 15 16 17 18 19 20 21 22 23 24 25 26 27 28 fAN8420D v v v v v a a a a a a a a a a v v 12v im3 vm7 r cs 0.5 w im2 5v vr1 10 m a 15 vm6 vr2 im1 vr3 im2 vr5 0.1 m f vm4 10 m a 14 vm5 20ma 13 vm3 im4 vr9 im5 im6 im7 im8 im9 vr10 vr11 vr12 vr13 sw3 a b c sw2 a b c sw1 a b c vm8 vr8 rl=5 w rl=5 w rl=5 w sw13 a b vm1 12v 300ma vm2 300ma v 10 m a 15 vm6 nc a3 nc a2 nc nc a1 gnd h1+ h1 - h2+ h2 - h3+ h3 - vh nc pc1 sb fg3x dir ecr ec ss fg1x vcc nc vm cs1 v
fAN8420D (ka3020d); preliminary 16 typical application circuits 1 2 3 4 5 6 7 8 9 10 11 12 13 14 19 18 17 16 15 22 21 20 23 24 25 26 27 28 hall 1 hall 3 servo signal st hall 2 1.675v sp v cc (5v) v m (12v) fAN8420D 0.5 w r2 r1 0.1 m f nc a3 nc a2 nc nc a1 gnd h1+ h1 - h2+ h2 - h3+ h3 - cs1 vm nc vcc fg1x ss ec ecr dir fg3x sb pc1 nc vh
28-ssoph-375 #1 #14 #15 #28 0.80 0.20 0.031 0.008 18.40 0.20 0.724 0.008 0.40 0.10 0.016 0.004 0.80 0.031 9.53 0.375 2.20 0.20 0.087 0.008 0.05 0.002 10.00 0.30 0.394 0.012 7.50 0.20 0.295 0.008 18.80 0.740 0~8 1.20 0.047 () 2.50 0.098 max0.10 max0.004 max max min + 0.10 -0.05 0.25 + 0.004 -0.002 0.010
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. life support policy fairchilds products are not authorized for use as critical components in life support devices or systems without the express written approval of fairchild semiconductor corporation. 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, or (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 significant injury to the user. 2. a critical component is 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. product status definitions definition of terms datasheet identification p roduct status definition advance information preliminary no identification needed obsolete this datasheet contains the design specifications for product development. specifications may change in any manner without notice. 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. this datasheet contains final specifications. fairchild semiconductor reserves the right to make changes at any time without notice in order to improve design. this datasheet contains specifications on a product that has been discontinued by fairchild semiconductor. the datasheet is printed for reference information only. formative or in design first production full production not in production 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. qfet? qs? qt optoelectronics? quiet series? supersot?-3 supersot?-6 supersot?-8 syncfet? tinylogic? uhc? fastr? globaloptoisolator? gto? hisec? isoplanar? microwire? optologic? optoplanar? pop? powertrench ? rev. f1 acex? bottomless? coolfet? crossvolt? dome? e 2 cmos tm ensigna tm fact? fact quiet series? fast ? vcx?

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