4/5

REV. A

CAUTIONS ON USE

(1)

The BA5955FP incorporates a TSD circuit (overheat protection circuit) and a reset circuit.

When the

chip temperature has reached 175℃ (typ.), the output current will be muted while the reset output will

become ‘L’ and, when the chip temperature has dropped to 150℃ (typ.), the mute function will be reset

while the reset output will be ‘H.’

The reset output also becomes ‘L’ in the standby state.

(2)

When the power supply voltage (PreVcc) has dropped to 3.8V (typ.) or less, the output current will be

muted while the reset output will become ‘L’ and, when PreVcc has recovered to 4.0V (typ.), the driver

part circuit will be initiated to set the reset output to ‘H.’

(3)

When the reference input (Vc) voltage has dropped to 0.8V (typ.) or less, the output current will be

muted while the reset output will become ‘L.’

Under conditions of normal use, it should be 1.2V (typ.) or above.

(4)

Thermal shutdown or a drop of reference voltage or power supply voltage will activate the mute

function, where only the driver part can be muted.

While muting, the voltage at the output terminal will

equal to the internal reference voltage (approximately PowVcc/2).

(5)

Connecting a capacitive load to the OP-AMP output results in a phase margin reduction of the amp and

may cause an oscillation or a peak.

When connecting a capacitive load, a resistance must be

inserted in series between the output and the capacitive load.

And after careful consideration of the

frequency characteristics, the device should be used within the range where no problem is found in

actual use.

(6)

A radiating fin must be connected to the external GND.

(7)

Short-circuits between output pin-VCC, output pin-GND, or output terminals (load short) must be

avoided.

Mounting the ICs in improper directions may damage them or produce smoke.

(8)

About absolute maximum ratings

Exceeding the absolute maximum ratings, such as the applied voltage or the operating temperature

range, may cause permanent device damage.

As these cases cannot be limited to the broken short

mode or the open mode, if a special mode where the absolute maximum ratings may be exceeded is

assumed, it is recommended to take mechanical safety measures such as attaching fuses.

(9)

About power supply lines

As a measure against the back current regenerated by a counter electromotive force of the motor, a

capacitor to be used as a regenerated-current path can be installed between the power supply and

GND and its capacitance value should be determined after careful check that any problems, for

example, a leak capacitance of the electrolytic capacitor at low temperature, are not found in various

characteristics.

(10) About GND potential

The electric potential of the GND terminal must be kept lowest in the circuitry at any operation states.

(11) About thermal design

With consideration of the power dissipation (Pd) under conditions of actual use, a thermal design

provided with an enough margin should be done.

(12) About operations in a strong electric field

When used in a strong electric field, note that a malfunction may occur.

(13) ASO

When using this IC, the output Tr must be set not to exceed the values specified in the absolute

maximum ratings and ASO.

(14) Thermal shutdown circuit

This IC incorporates a thermal shutdown circuit (TSD circuit).

When the chip temperature reaches the

value shown below, the coil output to the motor will be set to open.

The thermal shutdown circuit is designed only to shut off the IC from a thermal runaway and not

intended to protect or guarantee the entire IC functions.

Therefore, users cannot assume that the TSD circuit once activated can be used continuously in the

subsequent operations.

TSD ON Temperature

[

°C] (typ.)

Hysteresis Temperature

[

°C] (typ.)

175

25