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REV. A
{ CAUTIONS ON USE
(1) Setting the Standby terminal (pin 10) to 0.5V or less allows the circuit to enter the standby mode.
Under conditions of normal use, the pin 10 should be pulled-up to 2.0V or above.
(2) When PreVcc (pin 9) has dropped to 3.4V (typ.) or less, the output current will be muted and, when
PreVcc has recovered to 3.6V (typ.), the driver part circuit will be initiated.
(3) When the voltage applied on the Bias terminal (pin 20) has dropped to 0.7V (Typ.) or less, the mute
function will be activated. Under conditions of normal use, it should be set to 1.0V or above.
(4) Thermal shutdown (TSD), bias terminal voltage drop or power supply voltage drop will activate the
mute function, where only the driver part can be muted.
The output terminals will show the voltage equals to the internal reference voltage (approximately
(PowVcc-Vf)/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 probl em is found in actual use.
(6) Short-circuits between output pin-VCC, output pin-GND, or output terminals (load short) must be
avoided. Make sure that the ICs are installed on the board in proper directions.
Mounting the ICs in improper directions may damage them or produce smoke.
(7) 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.
(8) 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 an d
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.
(9) About GND potential
The electric potential of the GND terminal must be kept lowest in the circuitry at any operation states.
(10) 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.
(11) About operations in a strong electric field
When used in a strong electric field, note that a malfunction may occur.
(12) ASO
When using this IC, the output Tr must be set not to exceed the values specified in the absolute
maximum ratings and ASO.
(13) Thermal shutdown circuit
This IC incorporates a thermal shutdown circuit (TSD circuit). When the chip temperat ure 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
(14) About earth wiring patterns
When a small signal GND and a large current GND are provided, it is recommended that the large
current GND pattern and the small signal GND pattern should be separated and grounded at a single
point of the reference point of the set in order to prevent the voltage of the small signal GND from being
affected by a voltage change caused by the resistance of the pattern wiring and the large current.
Make sure that the GND wiring patterns of the external components will not change, too.