BD5431EFS_11 Datasheet, PDF (4/5 Pages) Rohm – Silicon monolithic integrated circuits

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○Operation Notes
（1） Absolute maximum ratings
Use of the IC in excess of absolute maximum ratings such as the applied voltage or operating temperature range 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. A physical safety measure such as a fuse should be implemented when use of the IC in a
special mode where the absolute maximum ratings may be exceeded is anticipated.
（2） Power supply lines
As return of current regenerated by back EMF of output coil happens, take steps such as putting capacitor between
power supply and GND as a 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.
（3） GND potential
Ensure a minimum GND pin potential in all operating conditions.
（4） Setting of heat
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.
Class-D power amplifier is High efficiency and low heat generation by comparison with conventional Analog power
amplifier. However, In case it is operated continuously by maximum output power, Power dissipation(Pdiss) may
exceed package dissipation. Please consider about heat design that Power dissipation(Pdiss) does not exceed
Package dissipation(Pd) in average power(Poav). （Tjmax ：Maximum junction temperature=150℃、Ta ：Peripheral
temperature[℃]、θja ：Thermal resistance of package[℃/W]、Poav：Average power[W]、η：Efficiency）
Package dissipation: Pd （W） = （Tjmax - Ta）／θja
Power dissipation: Pdiss（W） = Poav * （1／η- 1）
（5） Actions in strong magnetic field
Use caution when using the IC in the presence of a strong magnetic field as doing so may cause the IC to
malfunction.
（6） Thermal shutdown circuit
This product is provided with a built-in thermal shutdown circuit. When the thermal shoutdown circuit operates, the
output transistors are placed under open status. The thermal shutdown circuit is primarily intended to shut down the
IC avoiding thermal runaway under abnormal conditions with a chip temperature exceeding Tjmax = 150℃, and is not
intended to protect and secure an electrical appliance.
（7） Shorts between pins and misinstallation
When mounting the LSI on a board, pay adequate attention to orientation and placement discrepancies of the LSI. If
it is misinstalled and the power is turned on, the LSI may be damaged. It also may be damaged if it is shorted by a
foreign substance coming between pins of the LSI or between a pin and a power supply or a pin and a GND.
（8） Power supply on/off
In case power supply is started up, MUTEX（Pin20）always should be set LOW, And in case power supply is shut down,
it should be set LOW likewise. Then it is possible to eliminate pop noise when power supply is turned on/off. And
also, all power supply terminals should start up and shut down together.
（9） WARNING terminal(Pin18), ERROR terminal(Pin19)
A WARNING flag is outputted when Under Voltage Protection and High Temperature Protection are operated. A
Error flag is outputted when Output Short Protection and Output DC Voltage Protection are operated. These flags
are the function which the condition of this product is shown in. The use which aimed at the protection except for
this product is prohibition.
（10） N.C. terminal(Pin5, 21, 22, 44)
N.C. terminal(Non Connection Pin) does not connect to the inside circuit. Therefore, please open or connect to GND.
REV. B