TA7291P/S/SG/F/FG
Points to remember on handling of ICs
(1) Over current Protection Circuit
Over current protection circuits (referred to as current limiter circuits) do not necessarily protect
ICs under all circumstances. If the Over current protection circuits operate against the over current,
clear the over current status immediately.
Depending on the method of use and usage conditions, such as exceeding absolute maximum ratings
can cause the over current protection circuit to not operate properly or IC breakdown before
operation. In addition, depending on the method of use and usage conditions, if over current
continues to flow for a long time after operation, the IC may generate heat resulting in breakdown.
(2) Thermal Shutdown Circuit
Thermal shutdown circuits do not necessarily protect ICs under all circumstances. If the thermal
shutdown circuits operate against the over temperature, clear the heat generation status
immediately.
Depending on the method of use and usage conditions, such as exceeding absolute maximum ratings
can cause the thermal shutdown circuit to not operate properly or IC breakdown before operation.
(3) Heat Radiation Design
In using an IC with large current flow such as power amp, regulator or driver, please design the
device so that heat is appropriately radiated, not to exceed the specified junction temperature (TJ)
at any time and condition. These ICs generate heat even during normal use. An inadequate IC heat
radiation design can lead to decrease in IC life, deterioration of IC characteristics or IC breakdown.
In addition, please design the device taking into considerate the effect of IC heat radiation with
peripheral components.
(4) Back-EMF
When a motor rotates in the reverse direction, stops or slows down abruptly, a current flow back to the motor’s
power supply due to the effect of back-EMF. If the current sink capability of the power supply is small, the
device’s motor power supply and output pins might be exposed to conditions beyond maximum ratings. To avoid
this problem, take the effect of back-EMF into consideration in system design.
15
2007-06-13
TOSHIBA [ TOSHIBA ]
