BA6859AFP-Y [ROHM]
Three-phase motor driver for CD-ROMs; 三相电机驱动光盘
| 型号： | BA6859AFP-Y |
| 厂家： | 
ROHM |
| 描述： | Three-phase motor driver for CD-ROMs |
| 文件： | 总15页 (文件大小：208K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Motor driver ICs
Three-phase motor driver for
CD-ROMs
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
The BA6858A and BA6859A series are ICs developed for CD-ROM spindle motor drives. In addition to the functions
of the BA6849 series, (short brake, reverse-rotation prevention circuit, rotation direction dector, and FG output), the
BA6858A and BA6859A series have a built-in brake mode switching pin. With torque command input, these series are
compatible with the DSP3.3V. In addition, the BA6858A series has an FG composite output.
FApplications
CD-ROM, CD-R, CD-RW, DVD-ROM, and DVD-RAM
FFeatures
1) Three-phase, pseudo-linear drive system.
2) Built-in power save and thermal shutdown functions.
3) Built-in current limiter and Hall bias circuits.
4) Built-in FG output.
6) Built-in reverse rotation prevention circuit.
7) Built-in short brake pin.
8) Built-in brake mode switching pin.
9) DSP3.3V compatible.
5) Built-in rotation direction detector.
FAbsolute maximum ratings (Ta = 25_C)
848
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
FRecommended operating conditions (Ta = 25_C)
FBlock diagram
BA6858AFP / BA6858AFM
849
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
FPin descriptions
BA6858AFP/BA6858AFM
850
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
BA6859AFP/BA6859AFM
BA6859AFP-Y
851
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
BA6859AFS
852
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
FInput / output circuits
(1) Power save
(2) Torque command input
(3) Torque output (A1, A2, and A3)
)
*
)
*
)
*
(4) Hall input (H1 , H1 , H2 , H2 , H3 , H3
)
853
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
(5) Hall bias
(7) FG2 Output
(6) FG output
(8) FR output
(9) Short brake
854
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
(10) Brake mode
FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 5V, VM = 12V)
855
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
856
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
FCircuit operation
(1) Hall input to coil output
The phase relationship between the Hall input signals and the output current and voltage is shown in Fig.11. The motor
position data input via the Hall pins is amplified by the Hall amplifier, and formed into waveforms by the matrix block.
These signals are input to the output driver that supplies the drive current to the motor coils.
857
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
(2) Torque command
The RNF pin voltage with respect to the torque command (EC) is as follows:
The I / O gain (GEC) from the EC pin to the RNF pin (output
current) is determined by the RNF detector resistor.
GEC = 0.35 / RNF (A / V)
The torque limit current ITL is given by:
ITL = 0.35 / RNF (A)
(3) Reverse rotation detection function
The reverse detection circuit construction is shown in
Fig.13.
(1) Forward (EC < ECR)
The phase relationship between the Hall input signals
)
)
H2 and H3 becomes as shown in Fig.11, and the re-
verse rotation detection circuit does not operate.
(2) Reverse (EC > ECR)
)
The phase relationship between the signals H2 and
)
H3 is opposite that for forward operation, and the re-
verse rotation detection circuit operates. The output
goes OFF, and becomes open circuit.
858
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
(4) Short brake
(6) Power save
When 2.5V or more is applied to the short brake pin, the
top-side output transistors of all phases go off, and the
bottom-side output transistors go on. This applies brak-
ing to the motor. Short braking operates regardless of the
torque command signal.
When 2.5V or more is applied to the power save pin, all
circuits are on. When 1.0V or less is applied, the IC en-
terspowersavemode, andfunctionsonlyforsurpressing
power consumption.
(5) Brake mode switching
When 2.5V or more is applied to the BR pin, the brake
mode for when EC > ECR can be changed.
FApplication example
859
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
FOperation notes
(1) Torque command
enoperating with ECR = 2.5V, the voltage range for the
ue command input is 0.5V to 3.3V, and therefore, the
racteristic will be unbalanced as shown in Fig.15.
e due care.
(2) Switches
The switches have a temperature characteristic of
approximately –5mV / _C. Take care with regard to the
input voltage range.
(3) Hall input
The input circuit shown in Fig.4 is used for the Hall inputs.
The Hall elements can be connected either in series or in parallel.
Set the Hall input voltage in the range 1.0V to 4.0V.
Set the resistance values between VH and VCC pins and the Hall elements after calculating the current to flow in Hall
elements.
If there will not be a resistor connected between the Hall elements and the VH pin, we recommend that IVH = 5mA or more.
(4) Thermal shutdown (TSD)
When the junction temperature reaches 175_C (Typ.), the A1, A2, and A3 coil outputs go open circuit.
The thermal shutdown has approximately 15_C (Typ.) of hysteresis.
860
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
FElectrical characteristics curves
861
BA6858AFP / BA6858AFM / BA6859AFP /
BA6859AFP-Y / BA6859AFM / BA6859AFS
Motor driver ICs
FExternal dimensions (Units: mm)
862
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