495

Motor driver ICs

BA6238A / BA6238AN / BA6239A / BA6239AN

FOperation notes

(1)

Though the IC input pins can be directly connected

with MOS output pins, it is recommendable to connect re-

sistors of about 3

X 30kΩ between the pins for the sake

of pin protection (see Fig. 7).

(2)

When reversing the rotational direction of a motor,

make sure to go through the brake mode in-between the

opposite directions. It is recommendable to keep the

brake mode for at least 10

µs.

(3)

Powering procedures should be designed so that

(4)

The quality of these products have been carefully

checked; however, use of the products with applied volt-

ages, operating temperatures, or other parameters that

exceed the absolute maximum rating given may result in

the damage of the IC and the product it is used in. If the

IC is damaged, the short mode and open modes cannot

be specified, so if the IC is to be used in applications

where parameters may exceed the absolute maximum

ratings, then be sure to incorporate fuses, or other physi-

cal safety measures.

(5)

Input pins

Voltage should never be applied to the input pins when

electrical characteristics.

(6)

Back-rush voltage

Depending on the ambient conditions, environment, or

motor characteristics, the back-rush voltage may fluctu-

ate. Be sure to confirm that the back-rush voltage will not

adversely affect the operation of the IC.

(7)

Large current line

Large currents are carried by the motor power supply and

motor ground for these ICs.

Therefore, the layout of the pattern of the PC board and

the constants of certain parameters for external compo-

nents, such as the capacitor between the power supply

and ground, may cause this large output current to flow

back to the input pins, resulting in output oscillation or

other malfunctions. To prevent this, make sure that the

PC board layout and external circuit constants cause no

problems with the characteristics of these ICs.

(8)

Power dissipation

The power dissipation will fluctuate depending on the

mounting conditions of the IC and the ambient environ-

ment. Make sure to carefully check the thermal design of

the application where these ICs will be used.

(9)

Power consumption

The power consumption by the IC varies widely with the

power supply voltage and the output current. Give full

consideration to the power dissipation rating and the

thermal resistance data and transient thermal resistance

data, to provide a thermal design so that none of the rat-

ings for the IC are exceeded.

(10) ASO

Make sure that the output current and supply voltage do

not exceed the ASO values.

(11) Precautions for input mode switching

To ensure reliability, it is recommended that the mode

switching for the motor pass once through the open

mode.

(12) Factors regarding the thermal, power supply, and

motor conditions

If the potential of the output pin sways greatly and goes

below the potential of ground, the operation of the IC may

malfunction or be adversely affected. In such a case,

place a diode between the output and ground, or other

measure, to prevent this.