BD67922EFV ROHM Co. Ltd., BD67922EFV Datasheet - Page 4

• Manufacturer Part Number: BD67922EFV
• Description: 3-phase Brushless Motor Driver
• Manufacturer: ROHM Co. Ltd.

○Operation Notes
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(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10) Mounting errors and Inter-pin short
(11) TEST pin
Absolute maximum ratings
Power supply lines
GND potential
Metal on the backside (Define the side where product markings are printed as front)
Thermal design
Actions in strong electromagnetic field
ASO
Thermal shutdown circuit
Ground Wiring Pattern
An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating
conditions, etc., can break down the devices, thus making impossible to identify breaking mode, such as a
short circuit or an open circuit. If any over rated values will expect to exceed the absolute maximum ratings,
consider adding circuit protection devices, such as fuses.
As return of current regenerated by back EMF of motor happens, take steps such as putting capacitor
between power supply and GND as an electric pathway for the regenerated current. Be sure that there is no
problem with each property such as emptied capacity at lower temperature regarding electrolytic capacitor
to decide capacity value. 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.
The potential of GND pin must be minimum potential in all operating conditions.
The metal on the backside is shorted with the backside of IC chip therefore it should be connected to GND.
Be aware that there is a possibility of malfunction or destruction if it is shorted with any potential other than
GND.
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual
operating conditions. This IC exposes its frame of the backside of package. Note that this part is assumed
to use after providing heat dissipation treatment to improve heat dissipation efficiency. Try to occupy as
wide as possible with heat dissipation pattern not only on the board surface but also the backside.
The IC is not designed for using in the presence of strong electromagnetic field. Be sure to confirm that no
malfunction is found when using the IC in a strong electromagnetic field.
When using the IC, set the output transistor so that it does not exceed absolute maximum ratings or ASO.
The IC has a built-in thermal shutdown circuit (TSD circuit). If the chip temperature becomes Tjmax=150℃,
and higher, coil output to the motor will be open. The TSD circuit is designed only to shut the IC off to
prevent runaway thermal operation. It is not designed to protect or indemnify peripheral equipment. Do not
use the TSD function to protect peripheral equipment.
When using both large current and small signal GND patterns, it is recommended to isolate the two ground
patterns, placing a single ground point at the ground potential of application 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.
When attaching to a printed circuit board, pay attention to the direction of the IC and displacement.
Improper attachment may lead to destruction of the IC. There is also possibility of destruction from short-
circuits which can be caused by foreign matter entering between pins.
Be sure to connect TEST pin to GND.
REV. A
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