BU64240GWZ ROHM [Rohm], BU64240GWZ Datasheet - Page 5

• Manufacturer Part Number: BU64240GWZ
• Description: Silicon Monolithic Integrated Circuit
• Manufacturer: ROHM [Rohm]

Operation Notes
This specification is supposed to be revised for improvement etc
(1) Absolute maximum ratings
(2) Power supply lines
(3) Ground potential
(4) Setting of heat
(5) Actions in strong magnetic field
(6) ASO
(7) Thermal shutdown circuit
(8) Ground Wiring Pattern
(9) Power Save (PS) terminal
Use of the IC in excess of absolute maximum ratings such as the applied voltage or operating temperature range
(Topr) may result in IC damage. Assumptions should not be made regarding the state of the IC (short mode or
open mode) when such damage is suffered. The implementation of a physical safety measure such as a fuse
should be considered when use of the IC in a special mode where the absolute maximum ratings may be
exceeded is anticipated.
Regenerated current may flow as a result of the motor's back electromotive force. Insert capacitors between the
power supply and ground pins to serve as a route for regenerated current. Determine the capacitance in full
consideration of all the characteristics of the electrolytic capacitor, because the electrolytic capacitor may loose
some capacitance at low temperatures. If the connected power supply does not have sufficient current absorption
capacity, regenerative current will cause the voltage on the power supply line to rise, which combined with the
product and its peripheral circuitry may exceed the absolute maximum ratings. It is recommended to implement a
physical safety measure such as the insertion of a voltage clamp diode between the power supply and GND pins.
Ensure a minimum GND pin potential in all operating conditions.
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating
conditions.
Use caution when using the IC in the presence of a strong magnetic field as doing so may cause the IC to
malfunction.
When using the IC, set the output transistor for the motor so that it does not exceed absolute maximum ratings or
ASO.
This IC incorporates a TSD (thermal shutdown) circuit (TSD circuit). If the temperature of the chip reaches the
following temperature, the motor coil output will be opened. The thermal shutdown circuit (TSD circuit) is
designed only to shut the IC off to prevent runaway thermal operation. It is not designed to protect the IC or
guarantee its operation. Do not continue to use the IC after operating this circuit or use the IC in an environment
where the operation of this circuit is assumed.
When using both small signal and large current GND patterns, it is recommended to isolate the two ground
patterns, placing a single ground point at the application's reference point so that the pattern wiring resistance
and voltage variations caused by large currents do not cause variations in the small signal ground voltage. Be
careful not to change the GND wiring pattern of any external components, either.
PS holds the reset function on logic concurrently. Please release PS after the start-up of VCC. Reset is not
normally done when VCC is short-circuited to PS and it uses it, and there is a possibility of malfunctions.
TSD ON temperature [°C]
(Typ.)
150
Hysteresis temperature [°C]
REV. A
(Typ.)
20
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