3Phase spindle motor driver for CD-RW

Transcription

1 otor driver ICs BD6670F 3Phase spindle motor driver for CD-RW BD6670F BD6670F is a 3-phase spindle motor driver adopting 180 PW direct driving system. Noise occurred from the motor driver when the disc is driver can be reduced. ow power consumption and low heat operation are achieved by using DOS FET in output and driving directly.!applications CD-RW!Features 1) 180 degree Direct-PW driving system. 2) Built in power save circuit. 3) Built in current limit circuit. 4) Built in -output. 5) Built in 3phase synthesized -output. 6) Built in hall bias circuit. 7) Built in reverse protection circuit. 8) Built in short brake circuit. 9) ow consumption by OS-FET. 10) Built in capacitor for oscillator. 11) Built in gain switch and current limit switch.!absolute maximum ratings (Ta=25 C) Parameter Symbol imits Unit Power supply voltage Supply voltage for motor G pin voltage G Output current IOAX ma Power dissipation Pd mw Junction temperature Operating temperature range Storage temperature range TJAX Topr Tstg 1 owever, do not exceed Pd, ASO and Tj=150 C. The current is guaranteed 3.0A in case of the current is turn on / off in a duty-ratio of less than 1/10 with a maximum on-time of 5msec. 2 70mm 70mm 1.6mm glass epoxy board. Debating in done at 17.6mW / C for operating above Ta=25 C. 150 C 20~75 55~150 C C!Recommended operating conditions Parameter Power supply voltage Supply voltage for motor G pin voltage Symbol in. Typ. ax. Unit G /17

2 BD6670F otor driver ICs 2/17!Block diagram Torque AP Current sense Reverse detect Driver atrix C G Gain control Charge pump all bias atrix Fig.1 D Q CK QB EXOR PW Comp all comp all Amp TSD OSC U-Pre Driver -Pre Driver

3 otor driver ICs BD6670F!Pin descriptions Pin No Pin name G Function all input AP 1 positive input all input AP 1 negative input all input AP 2 positive input all input AP 2 negative input all input AP 3 positive input all input AP 3 negative input Gain switch pin Capacitor pin 1 for charge pump Capacitor pin 2 for charge pump Capacitor connection pin for charge pump Capacitor connection pin for phase compensation Short brake pin Power supply for signal division Power supply for driver Torque control standard voltage input terminal Torque control voltage input terminal Power save pin Resistor connection pin for current sense Output 3 for motor Resistor connection pin for current sense Output 2 for motor Resistor connection pin for current sense Output 1 for motor Power supply for driver all bias pin output pin output pin 3/17

4 otor driver ICs BD6670F!Input output circuits all input 1 : Pin1, 1 : Pin2, 2 : Pin3, 2 : Pin4, 3 : Pin5, 3 : Pin6 Gain switch Pin7 output Pin9 100k n 1k 1k n 1k 75k 10k 50 (Pin9) 1k 5k 1k Gain Switch (Pin7) 10k 25k / G output : Pin10, G : Pin11 Pin12 Short brake Pin13 G (Pin11) (Pin12) 50 (Pin13) 30k (Pin10) 20k 2k 2k Torque amplifier : Pin16, : Pin17 Power save Pin18 Pin19 (Pin16) (Pin17) 1k (Pin18) 30k 20k (Pin19) 1k 355 Output pins : Pin24, : Pin22, : Pin20 all bias Pin26 / output : Pin27, : Pin28 (Pin26) 50 (Pin27) (Pin28) 100k 4/17

5 otor driver ICs BD6670F!Electrical characteristics (unless otherwise noted, Ta=25 C, =5, =12) Parameter Symbol in. Typ. ax. Unit Conditions Test Circuit <Total> Circuit current 1 ICC µa Stand by mode Fig.2 Circuit current 2 ICC ma Fig.2 <Power save> ON voltage range ON 1.0 Stand by mode Fig.2 OFF voltage range OFF 2.5 Fig.2 <all bias> all bias voltage B IB=10mA Fig.2 <all AP> In-phase input voltage range AR Fig.3 inimum input level IN 80 mpp Oneside input level Fig.3 all hysteresis level () YS m Fig.3 all hysteresis level () YS m Fig.3 <Gain switch> ow voltage range 0.6 Fig.4 igh voltage range Open voltage range OP Fig.4 Fig.4 <Torque control> Input voltage range Offset voltage () Offset voltage (), Ecofs Ecofs m m inear range : Fig.6 Fig.6 Fig.6 Input current Input / Output gain Input / Output gain IN G G µa A/ A/ ==1.65 GS=, RNF=0.5Ω GS=, RNF=0.5Ω Fig.6 Fig.7 Fig.7 Input / Output gain <Output> G A/ GS=, RNF=0.5Ω Fig.7 Output ON-resistance RON Ω IO=±600mA (Upperower) Fig.8 Torque limit current IT ma =, RNF=0.5Ω Fig.4 Torque limit current IT ma =, RNF=0.5Ω Fig.4 Torque limit current IT ma =, RNF=0.5Ω Fig.4 < / output> igh voltage 4.6 I=100µA Fig.5 ow voltage 0.4 I=100µA Fig.5 <Charge pump voltage> Charge pump output voltage PUP =5, =12, ==0.1µF Fig.9 < output> Upper saturation voltage I=4mA Fig.10 ower saturation voltage I=4mA Fig.10 < output> Upper saturation voltage I=4mA Fig.11 ower saturation voltage I=4mA Fig.11 5/17

6 otor driver ICs BD6670F!easuring circuit 0.5Ω 0.01µ 12 10kΩ 1.65 ICC1 : alue of A =ow ICC2 : alue of A =igh ON : Range of that output pins become Input-output table G OFF : Range of that output become open A B : alue of A =5 I=10mA Fig.2 0.5Ω 0.01µ 12 10kΩ AR : all in-phase input voltage range that output pins become Input-output table IN : all minimum input level that output pins become Input-output table G YS / : oltage difference 3 from 3 at the point that voltage changes Fig.3 6/17

7 otor driver ICs BD6670F IT : Defining as the voltage that becomes low, IT= / 0.5 =ow IT : Defining as the voltage that becomes low, IT= / 0.5 =Open IT : Defining as the voltage that becomes low, IT= / 0.5 =igh G : Range of that IT < IT : Range of that IT > IT Fig OP : alue of : I (I) = alue of 2(3) at I (I) = 100µA 1=, 2=, 3= 1=, 2=, 3= (for ) 1=, 2=, 3= 1=, 2=, 3= (for ) G : I (I) = alue of 2(3) at I (I) = 100µA 1=, 2=, 3= 1=, 2=, 3= (for ) 1=, 2=, 3= 1=, 2=, 3= (for ) Fig.5 7/17

8 otor driver ICs BD6670F 0.5Ω 0.01µF 5Ω Ω 10kΩ 5Ω 5 / : Torque control operating range OfS / : voltage range that current is 0A monitor IN : alue of and at == G µF 100pF Fig.6 0.5Ω 0.01µ 12 5Ω 5Ω 10kΩ 5Ω G : Defining 1 as value of at =1.2 and 2 as value of at =1.5 on condition that =0, G={(12) / (1.51.2)} / 0.5 G : Defining 1 as value of at =1.2 and 2 as value of at =1.5 on condition that =open, G={(12) / (1.51.2)} / G G : Defining 1 as value of at =1.2 and 2 as value of at =1.5 on condition that =5, G={(12) / (1.51.2)} / pF Fig.7 8/17

9 otor driver ICs BD6670F O : alue of on condition that output pin is and IO=600mA O : alue of on condition that output pin is and IO=600mA RON : RON = (O O) / G ,, 600mA,, 600mA easurement of O easurement of O Fig PUP : alue of G µF Fig.9 9/17

10 otor driver ICs BD6670F : alue of on condition that is and I=4mA : alue of on condition that is and I=4mA G Fig : alue of on condition that is and I=4mA : alue of on condition that is and I=4mA G Fig.11 10/17

11 otor driver ICs BD6670F!Circuit operation 1. Application (1) Input-output table Pin No. Condition 1 Condition 2 Condition 3 Condition 4 Condition 5 Condition 6 Input condition < Output condition > (2) all input all element can be used with both series and parallel connection. Determining R1 and R2, make sure to leave an adequate margin for temperature and dispertion in order to satisfy in-phase input voltage range and minimum input level. A motor doesn t reach the regular number of rotation, if hall input decrease under high temperature. R1 R R2 R2 Parallel connection Series connection Fig.12 11/17

12 otor driver ICs BD6670F (3) Torque voltage By the voltage difference between and, the current driving motor changes as shown in Fig.13 below. I [A] Forward torque Reverse torque IT 0 [] Fig.13 The gain of the current driving motor for the voltage of can be changed by the resistance of RNF and the voltage of. G=0.175 / RNF [A / ] (=) G=0.35 / RNF [A / ] (=) G=0.70 / RNF [A / ] (=) (4) Current limit The maximum value of the current driving motor can be changed by the resistance of RNF and the voltage of. IT=0.2 / RNF [A] (=) IT=0.4 / RNF [A] (=) IT=0.6 / RNF [A] (=) 12/17

13 otor driver ICs BD6670F (5) Short brake The short brake is switched by pin and its operation is shown in table below. < Rotating forward Short brake > Reverse brake Short brake Output upper (3phase) FET turn off and lower (3phase) FET turn on in short brake mode, as shown Fig.14. OFF OFF OFF ON ON ON RNF OTOR Fig.14 (6) Reverse detection Reverse detection is constructed as shown in Fig.15. Output is opened when > and the motor is rotating reverse. 2 2 D Q OUT 3 3 CK Fig.15 13/17

14 otor driver ICs BD6670F otor rotation at reverse detection Forward rotation (forward torque) when < Deceleration (reverse torque) when > Reverse detection is triggered and set outputs to open, when motor rotates in the reverse direction. otor idles in the reverse direction by inertia. Stop 14/17

15 otor driver ICs BD6670F (7) Timing chart Output current Output voltage Output current Output voltage Output current Output voltage Fig.16 15/17

16 otor driver ICs BD6670F!Application example 100Ω 1 all comp EXOR pF pF all Amp PW Comp TSD all bias pF 100Ω 3 U-Pre Driver 0.5Ω Gain control OSC atrix Driver -Pre Driver 0.1µF Charge pump 10kΩ 0.1µF G 0.01µF 100pF 10µF atrix D CK Q QB Reverse detect Current sense C Torque AP Servo signal µF Fig.17!Operation notes 1. Absolute maximum ratings Absolute maximum ratings are those values which, if exceeded, may cause the life of a device to become significantly shorted. oreover, the exact failure mode cannot be defined, such as a short or an open. Physical countermeasures, such as fuse, need to be considered when using a device beyond its maximum ratings. 2. potential The terminal should be the location of the lowest voltage on the chip. All other terminals should never go under this level, even in transition. 16/17

17 otor driver ICs BD6670F 3. Thermal design The thermal design should allow enough margin for actual power dissipation. 4. ounting failures ounting failures, such as misdirection or mismounts, may destroy the device. 5. Electromagnetic fields A strong electromagnetic field may cause malfunctions. 6. Coil current flowing into A coil current flows from motor into when torque control input changes from < into >, and voltage rises if voltage source doesn t have an ability of current drain. A protect circuit turns on and a current (40mA (typ.)) flows from to when voltage reaches to 15 (Typ.). ake sure that surrounding circuits work correctly and aren t destroyed, when voltage rises. Physical countermeasures, such as a diode for voltage clamp, need to be considered under these conditions. 7. pin An appropriate capacitor (100pF (typ.)) at pin make motor current smooth. ake sure the motor current doesn t oscillate, even in transition.!electrical characteristics curve Pd (W) Ta ( C) 70mm 70mm 1.6mm glass epoxy board. Debating in done at 17.6mW/ C for operating aboveta=25 C. Fig.18 Power dissipation curve!external dimensions (Units : mm) 18.5± ± ± ± ± ± ± ± ± S SOP-28 17/17