Technical Note
BA6956AN,BA6287F,BA6285FS,BA6285AFP-Y,BA6920FP-Y
●External application components
1) Resistor for the current limitation, R1
This is a current limiting resistor for collector loss reduction and at the time of short-circuited output. It depends on the
power supply voltage used, etc., but choose resistance of about 5 to 10Ω. In addition, set resistance with utmost care
to voltage drop caused by inrush current that flows when the motor is started.
2) Resistors and zener diode for the output high voltage setting, R2, R3 and ZD
These are the resistors and zener diode used when output high voltage is set. As for the voltage, only ( VSAT + VF )
lower than the VREF pin voltage for BA6287F, BA6285FS and BA6285AFP-Y. (Reference values; VSAT ≈ 0.25V, VF ≈
0.75V) Zener diode ZD is recommended to be used instead of resistor R3 when the power supply voltage is unstable
for BA6956AN and BA6920FP-Y.
3) Stabilization capacitor for the power supply line, C1
Please connect the capacitor of 1μF to 100μF for the stabilization of the power supply line, and confirm the motor
operation.
4) Phase compensating capacitor, C2, C3
Noise is generated in output pins or oscillation results in accord with the set mounting state such as power supply
circuit, motor characteristics, PCB pattern artwork, etc. As noise oscillation measures, connect 0.01μF to 0.1μF
capacitors.
●Functional descriptions
1) Operation modes
Table 6 Logic table
IN1
L
IN2
L
OUT1
OUT2
Operation
Stop (idling)
OPEN*
OPEN*
H
L
H
L
L
L
H
L
Forward (OUT1 > OUT2)
Reverse (OUT1 < OUT2)
Brake (stop)
L
H
H
H
* OPEN is the off state of all output transistors. Please note that this is the state of the connected diodes, which differs from that of the mechanical relay.
** Output OUT1 and OUT2 become OPEN regardless of the input logic of FIN and RIN when switching to the power save mode with the POWERSAVE pin.
a) Stand-by mode
In stand-by mode, all output power transistors are turned off, and the motor output goes to high impedance.
b) Forward mode
This operating mode is defined as the forward rotation of the motor when the OUT1 pin is high and OUT2 pin is
low. When the motor is connected between the OUT1 and OUT2 pins, the current flows from OUT1 to OUT2.
c) Reverse mode
This operating mode is defined as the reverse rotation of the motor when the OUT1 pin is low and OUT2 pin is
high. When the motor is connected between the OUT1 and OUT2 pins, the current flows from OUT2 to OUT1.
d) Brake mode
This operating mode is used to quickly stop the motor (short circuit brake).
Note) Switching of rotating direction (FWD/REV)
When the rotating direction is changed over by the motor rotating condition, switch the direction after the motor is
temporarily brought to the BRAKE condition or OPEN condition. It is recommended to keep the relevant conditions
as follows:
via BRAKE: Longer than braking time*. (* the time required for the output L terminal to achieve potential below GND when brake is activated.)
via OPEN: The time longer than 1 ms is recommended.
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2011.05 - Rev.B
11/17
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