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●IC Operation

BA6920FP-Y(BA6219BFP-Y)

1) I/O mode of input block FIN (IN1) and RIN (IN2)

A pin where control signals are input. Each mode operates as explained below.

When the FIN (IN1) is set to high and RIN (IN2) is set to low, the forward rotation mode will be set and a current will flow from OUT1 to

OUT2. When the FIN (IN1) is set to low and RIN (IN2) is set to high, the reverse rotation mode will be set and a current will flow from

OUT2 to OUT1. When both FIN (IN1) and RIN (IN2) are set to high, the brake mode will be set. At that time, the output transistor on the

high side will be turned off to stop the supply of the motor drive current while the output transistor on the low side will be turned on to

absorb the motor back EMF to brake the motor. When both FIN (IN1) and RIN (IN2) are set to low, OUT1 and OUT2 will be both open

potential and the motor will stop.

2) High output voltage setting function

With this function, the output voltage can be set through the high output voltage setting pin in order to control the rotation speed of the

motor. If the high output voltage is set to a lower value, the power consumption of the IC will become high. Consider the power

dissipation (Pd) of the IC under actual operating conditions, and implement thermal designing with a sufficient margin.

2-1. BA6219BF-Y (See Fig.14)

High output voltage is expressed by the following equation.

VoutH (high output voltage) = VR + {VF(Q5) + VF (Q6) + VF (Q7) - VF (Q2) -VF (Q3) - VF (Q4)}

≒VR +ΔVF

(VF is the base-emitter voltage in the forward direction)

Although ΔVF depends on the output current, Vo is almost VR.

The maximum value VoutHmax of high output voltage that can be set is as follows.

VoutHmax < VCC1 - Vsat (Q1) - VF (Q2) - VF (Q3) - VF (Q4)

≒VCC1 - 2.5 V

Relation of VCC1, VCC2, and VR

VCC1, VCC2, and VR should be set as follows.

VR < VCC2 - Vsat (Q3) + VF (Q3) + VF (Q2) - {VF (Q5) + (Q6) + (Q7)}

≒VCC2 - 1 V

Operating Conditions

Pin

Voltage

Unit

VCC1

8 ～ 18

V

VCC2

8 ～ 18

V

VR

Shown above

-

2-2. BA6920FP-Y (See Fig. 16)

High output voltage is expressed by the following equation:

VoutH (high output voltage) = Vref voltage + {VF (Q2) + VF( Q3)} - {VF(Q4) + VF (Q5)}

≒Vref voltage +ΔVF

(VF is the base-emitter voltage in the forward direction)

Although ΔVF depends on the output current, Vo is almost VR.

The VOH is beyond control if the Vref value is higher than the above, and determined

by the voltage condition of VCC and VM.

For example, when Vref = VCC

= VM,

VOH≒VCC - Vsat (Q1) - VF (Q4) -VF (Q5)

≒VCC - 1.7 V

Relation of VCC, VM, and VREF

VCC1, VCC2, and VR should be set as follows.

VREF < VM - Vsat (Q5) + VF (Q5) + VF (Q4) - {VF (Q2) + (Q3)}

≒ VM - 0.3 V

Operating conditions

pin

Voltage

Unit

6.5 ～ 34

V

VM

6.5 ～ 34

V

VREF

Shown above

-

3 ) Selection of forward or reverse rotation

To change the rotation direction of the motor in operation, be sure to brake or open the motor current on time.

In the above case,

Braking: The braking time or over. The braking time is defined as the time of setting the output low level voltage to the GND

potential or below, when the brake operates.

Opening: A period of 1 ms or over is recommended.

Fig.15

Output Voltage Control Range

VR (VREF) voltage

High output voltage

VCC1

VCC2

Q1

Q2

Q5

Q6

Q7

Q3

Q4

OUT

VR

Fig.14

Q1

Q2

Q3

Q4

Q5

OUT

VREF

VM

VCC

Fig.16