Rainbow Electronics BA6247FP-Y - Manual (Page 4)

501
Motor driver ICs BA6246N / BA6247 / BA6247N / BA6247FP-Y
F
Operation notes
(1) Input conditions
( 1) The input threshold voltage is positively correlated
with temperature as expressed by :
( 2) The input pins of the BA6246N are pulled up through
a resistance of about 15k
Ω
(see Fig. 1). To secure the
LOW level input, the interface to these pins should have
a current-sink capability of at least 700
µ
A
(5V / 15k
Ω
2).
( 3) The maximum input voltage is 6V. Make sure that the
input will not exceed this value. Also when the voltage
V
CC
is not applied to the IC, do not apply voltages to the
input pins.
(2)
Changes in motor direction
When reversing the rotational direction of a motor, make
sure to go through the brake or open mode in-between
the opposite directions.
The duration of brake mode should be more than the
braking time, which is defined by the time required for the
potential of the LOW level output pin to become less than
the ground potential by the electromotive force gener-
ated when the mode is switched from rotation to brake.
The duration of open mode should be 1 ms or more.
(3)
Due to the effects of capacitors C
2 X C
5
, the motor
that is not being driven could be momentarily driven dur-
ing mode switching. Check for this problem when design-
ing your application.
(4)
It is recommendable to arrange your design so that
voltage rises at V
CC1
prior to V
CC2
when turning on the
power, and voltage falls at V
CC1
after V
CC2
when turning
off the power.
(5)
Thermal shutdown circuit
When the thermal shutdown circuit is activated, the out-
puts are left OPEN. The circuit is activated when the IC
junction temperature rises above 170
_ C. The tempera-
ture difference between the activation and deactivation
settings is about 30
_
C.
(6) 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
retings, then be sure to incorporate fuses, or other physi-
cal safety measures.
(7)
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.
(8)
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 pa-
rameters for external components, such as the capacitor
between the power supply and ground, may cause this
large output current to flow back to the input pins, result-
ing in output oscillation or other malfunctions. To prevent
this, make sure that the PC board layout and external cir-
cuit constants cause no problems with the characteris-
tics of these ICs.
(9)
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.
(10) Power consumption
The power consumption by the IC varies widely with the
power supply voltage and the putput 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.
(11) ASO
Make sure that the output current and supply voltage do
not exceed the ASO values.
(12) In-rush current
There are no circuits built into these ICs that prevent in-
rush currents. Therefore, it is recommended to place a
current limiting resistor or other physical countermeasure.
(13) 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.
∆
T
∆
V
IH )
2.8mV /
_
C
∆
T
∆
V
IL )
1.6mV /
_
C (Typ.)