bd67929efv ROHM Co. Ltd., bd67929efv Datasheet - Page 12

• Manufacturer Part Number: bd67929efv
• Description: Three-phase Brushless Motor Driver For Polygonal Mirrors [for Lbp, Ppc]
• Manufacturer: ROHM Co. Ltd.

●Notes for use
BD67929EFV
© 2010 ROHM Co., Ltd. All rights reserved.
www.rohm.com
(10) Thermal shutdown circuit
(11) Inspection of the application board
(1) Absolute maximum ratings
(2) Connecting the power supply connector backward
(3) Power Supply Lines
(4) GND Potential
(5) Metal on the back side (Define the side where product markings are printed as front)
(6) Thermal design
(7) Inter-pin shorts and mounting errors
(8) Operation in a strong electric field
(9) ASO
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.
Connecting of the power supply in reverse polarity can damage IC. Take precautions when connecting the power supply
lines. An external direction diode can be added.
Design PCB layout pattern to provide low impedance GND and supply lines. To obtain a low noise ground and supply line,
separate the ground section and supply lines of the digital and analog blocks. Furthermore, for all power supply terminals
to ICs, connect a capacitor between the power supply and the GND terminal. When applying electrolytic capacitors in the
circuit, 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 is equipped with FIN heat dissipation terminals, but dissipation efficiency can be improved by applying heat
dissipation treatment in this area. It is important to consider actual usage conditions and to take as large a dissipation
pattern as possible.
When attaching to a printed circuit board, pay close attention to the direction of the IC and displacement. Improper
attachment may lead to destruction of the IC.
Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to
malfunction.
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.
During inspection pf the application board, if a capacitor is connected to a pin with low impedance there is a possibility
that it could cause stress to the IC, therefore an electrical discharge should be performed after each process. Also, as a
measure again electrostatic discharge, it should be earthed during the assembly process and special care should be
taken during transport or storage. Furthermore, when connecting to the jig during the inspection process, the power
supply should first be turned off and then removed before the inspection.
TSD on temperature [℃] (Typ.)
175
12/14
Hysteresis Temperature [℃] (Typ.)
25
Technical Note
2010.12 - Rev.A