bd6761fs ROHM Co. Ltd., bd6761fs Datasheet - Page 21

• Manufacturer Part Number: bd6761fs
• Description: Motor Driver Ic Series For Printers Three-phase Brushless Motor Pre-driver For Paper Feed Us
• Manufacturer: ROHM Co. Ltd.

⑬Phase compensation capacitor (BA6680FS, BD6761FS)
⑭VCC pin
⑮Charge pump filter (BA6680FS)
⑯Output FET gate voltage stabilization resistor
⑰Peak hold setting capacitor (BD6761FS)
⑱Motor locking detection time setting capacitor (BD6762FV)
⑲Integration amplifier constant setting (BD6762FV)
⑳LPF external constant (BD6762FV)
※Setting values in these materials are only for reference. Actual set may change its characteristics due to the board layout, wiring and
When the pole frequency is set to fP1 and fP2, they are:
fP1=ω
fP2=ω
fP2=ω
components each type uses. Please perform the sufficient verification using the actual product for the field operation.
Phase compensation is performed in the output of the CS amplifier.
The capacitance value should be selected according to the servo
constant, and proper motor operation should be confirmed. When
the capacitance is large, the I/O response becomes bad. When it is
small, the output can easily oscillate.
Set up the capacitance for the stabilization and noise reduction on
the power line.
Filter composed of C3, C4 and R3 smoothes the current pulses
output from the CPOUT pin and converts it to DC.
This impedance Z is shown by the following equation:
Z = R3×
When the pole frequency is set to fP1 and fP2, they are:
fP1=ω
When the noise is generated at the time of external MOSFET
on/off, due to the rise and fall speed of the IC output, insert the
resistor between the IC output and external MOSFET gate.
Charges the peak hold on the voltage at the current detection pin
CL.
Motor locking detection time T
which is connected to the LP pin and the count number CLP
(Preset value: 96) of the internal counter. The T
following equation:
TLP=2×10
Speed discriminator side current value ID is shown by ｜ I
=2.5/R4 and the PLL side current value IP is shown by｜I
=2.5/R5.
Therefore, the current I
pin INTIN is shown by I
The larger the I
becomes.
Gains of the speed discriminator and PLL can be set by adjusting
R4 and R5.
Gain G is shown by the following equation:
Filter composed of C8, C9 and R7 smoothes the current pulses
output from the LPF pin and converts it to DC.
This impedance Z is shown by the following equation:
When the pole frequency is set to fP1 and fP2, they are:
fP1=ω
Z = R7×
G =
1
2
2
1
1
/2π=1/2π(C5//C6)×R6
/2π=1/2πC6R6
/2π=1/2πC4R3
/2π=1/2π(C3//C4)R3
/2π=1/2π(C8//C9)R7
R4 // R5
5
×C7×96
C3+C4
R6
C8+C9
C4
C9
IN
is, the higher the integration amplifier gain
IN
Design method
×
IN
=I
×
which flows in the integration AMP input
D
×
+I
C5+C6
P.
LP
C6
S 1+
is determined by the capacitor C7
S 1+
fP2=ω
S+ω
S+ω
2
ω
×
/2π=1/2πC9R7
S
2
ω
S
1
2
1
S 1+
LP
is shown by the
S+ω
ω
S
2
1
21/24
D
P
｜
｜
A value of 0.001μF to 0.1μF is recommended.
A value of 0.001μF is appropriate for BA6680FS.
A value of 0.1μF is appropriate for BD6761FS.
A value of value 1μF to 10μF is recommended.
A value of 10μF is appropriate.
Recommended values:
C3: 0.01μF to 0.1μF; a value of 0.01μF is appropriate.
C4: 0.033μF to 0.33μF; a value of 0.1μF is appropriate.
R3 : 30kΩ to 300kΩ; a value of 100kΩ is appropriate.
Establish R so that the simultaneous on prevention time does
not exceeded as shown in #7. Output simultaneous on
prevention circuit in P.17/24 Operating Explanation.
A value of R = 0Ω is appropriate.
A value of 0.33μF is appropriate.
A value of 0.22μF is appropriate.
Recommended values:
R4: 10kΩ to 40kΩ; a value of 20 kΩ is appropriate.
R5: 300kΩ to 3MΩ; a value of 1 MΩ is appropriate.
R6: 100kΩ to 500kΩ; a value of 220 kΩ is appropriate.
C5: 0.01μF to 0.1μF; a value of 0.047μF is appropriate.
C6: 0.033μF to 1.0μF; a value of 0.47μF is appropriate.
Recommended values:
C8: 0.1μF to 0.6μF; a value of 0.33μF is appropriate.
C9: 0.1μF to 0.6μF; a value of 0.33μF is appropriate.
R7: 0.5kΩ to 10kΩ; a value of 2kΩ is appropriate.
Design example