TB62713N/F
2006-06-14
27
IC Usage Considerations
Notes on Handling of ICs
(1) The absolute maximum ratings of a semiconductor device are a set of ratings that must not be
exceeded, even for a moment. Do not exceed any of these ratings.
Exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result
injury by explosion or combustion.
(2) Use an appropriate power supply fuse to ensure that a large current does not continuously flow in
case of over current and/or IC failure. The IC will fully break down when used under conditions that
exceed its absolute maximum ratings, when the wiring is routed improperly or when an abnormal
pulse noise occurs from the wiring or load, causing a large current to continuously flow and the
breakdown can lead smoke or ignition. To minimize the effects of the flow of a large current in case of
breakdown, appropriate settings, such as fuse capacity, fusing time and insertion circuit location, are
required.
(3) If your design includes an inductive load such as a motor coil, incorporate a protection circuit into the
design to prevent device malfunction or breakdown caused by the current resulting from the inrush
current at power ON or the negative current resulting from the back electromotive force at power OFF.
IC breakdown may cause injury, smoke or ignition.
Use a stable power supply with ICs with built-in protection functions. If the power supply is unstable,
the protection function may not operate, causing IC breakdown. IC breakdown may cause injury,
smoke or ignition.
(4) Do not insert devices in the wrong orientation or incorrectly.
Make sure that the positive and negative terminals of power supplies are connected properly.
Otherwise, the current or power consumption may exceed the absolute maximum rating, and
exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result
injury by explosion or combustion.
In addition, do not use any device that is applied the current with inserting in the wrong orientation
or incorrectly even just one time.
(5) Carefully select external components (such as inputs and negative feedback capacitors) and load
components (such as speakers), for example, power amp and regulator.
If there is a large amount of leakage current such as input or negative feedback condenser, the IC
output DC voltage will increase. If this output voltage is connected to a speaker with low input
withstand voltage, overcurrent or IC failure can cause smoke or ignition. (The over current can cause
smoke or ignition from the IC itself.) In particular, please pay attention when using a Bridge Tied
Load (BTL) connection type IC that inputs output DC voltage to a speaker directly.
Points to Remember on Handling of ICs
(1) 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.
(2) 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.