TBD62304A series
2017-03-24
Notes on Contents
1. Pin Connection
Pin connection may be simplified for explanatory purpose.
2. Equivalent Circuit
Equivalent circuit may be simplified for explanatory purpose.
3. Test Circuit
Test circuit may be simplified for explanatory purpose.
4. Timing Chart
Timing charts may be simplified for explanatory purposes.
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 device breakdown, damage or
deterioration, and may result in injury by explosion or combustion.
(2) 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 device breakdown, damage or deterioration, and may result
in injury by explosion or combustion. In addition, do not use any device inserted in the wrong orientation or incorrectly
to which current is applied even just once.
(3) Use an appropriate power supply fuse to ensure that a large current does not continuously flow in the case of
overcurrent 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 to smoke or ignition. To minimize the
effects of the flow of a large current in the case of breakdown, appropriate settings, such as fuse capacity, fusing time
and insertion circuit location, are required.
(4) 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.
(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 from 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 may cause smoke or ignition. (The overcurrent may
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
Heat Radiation Design
When using an IC with large current flow such as power amp, regulator or driver, design the device so that heat is
appropriately radiated, in order not to exceed the specified junction temperature (Tj) at any time or under any 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, when designing the device, take into consideration the
effect of IC heat radiation with peripheral components.
Back-EMF
When a motor rotates in the reverse direction, stops or slows abruptly, current flows back to the motor’s power supply
owing 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 the absolute maximum ratings. To avoid this problem, take
the effect of back-EMF into consideration in system design.
