YDA137 Datasheet, PDF (13/20 Pages) YAMAHA CORPORATION – D- 2 STEREO 5W DIGITAL AUDIO POWER AMPLIFIER

YDA137
■Precaution for mounting
Thermal Pad for heat radiation is carried in the package backside of YDA137.
Sufficient heat radiation effect is acquired by creating a land pattern like following "Land pattern example of Thermal Pad
connection" and soldering "Thermal Pad" of YDA137 on the printed circuit board which mounts YDA137.
In addition, heat radiation to backside of the printed circuit board can be effectively performed by preparing a through hole
on a printed circuit board.
■Application notes
Warning for the device which makes sound using speaker
A speaker radiates heat in a voice-coil by air flow accompanying vibration of an oscillating board. When DC signal (several
Hz or less) is inputted, heat radiation characteristics falls rapidly.
In addition, even if it is used lower than rated input, it may lead to disconnection of a voice-coil, emitting smoke or ignition
of a speaker.
In order to avoid such situations, be sure to implement one or more preventive measures from the following.
1. Do not select a setup (sound production) which may generate DC signal.
(Since thoroughness of this preventive measure is generally difficult, we recommends the combined use with the
following 2, 3, and 4)
2. Add a DC cut digital filter for cutting DC signal into a digital section.
(As long as "Built-in" is not mentioned in the manual, there is no such built-in circuit inside of a device).
3. Add a DC cut capacitor for cutting DC signal into an analog section.
(When addition is specified in the example of a recommended circuit diagram, be sure to add)
4. When a latter stage device exists in the signal path from this device to speaker, DC cut is realized in a latter stage
device.
In addition, the above-mentioned measures are made that the device it-self, DC cut condenser, and a latter stage device will
be in a normal operation. Therefore, it is also necessary to implement the safety measures supposing failure of these parts
separately.
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