YDA143 Datasheet, PDF (9/22 Pages) YAMAHA CORPORATION – D- 3M STEREO 15W DIGITAL AUDIO POWER AMPLIFIER

YDA143
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●5V Regulator Function
YDA143 outputs 5V to REFA terminal when SLEEPN terminal is H. Connect a 1µF or more capacitor to REFA terminal
for voltage stabilization.
Connect REFA terminal to DVDD terminal on a board. And, do not connect the REFA terminal to other terminals except
for DVDD terminal and YDA143 control terminals.
●Pop Noise Reduction Function
The Pop Noise Reduction Function works in the following cases: Power-on, Power-off, Sleep ON/OFF, Mute ON/OFF, and
switching time between headphone amplifier and digital amplifier.
Pop noise at the Power-on, Power-off, and Sleep ON/OFF depends on the value of DC-cut capacitor for audio input signal.
The smaller the value, the greater the effect on the pop noise reduction; however, 0.22µF or more of capacitance is
recommended in the consideration of the low frequency cutoff.
●Correspond to Filter less
Normally, when LC filter is not used, carrier signal of 50% modulation comes into speaker even in no input signal state and
causes significant loss, and as the result the speaker is heated.
Generally, 15W speaker or so is considered to have inductance component of not less than 20µH.
In the modulation method of YDA143, duty ratio of the carrier signal is several % in no input signal state, so the speaker
inductance component can sufficiently inhibit speaker loss without LC filter; therefore, the speaker is not heated.
●Speaker Inductance
When YDA143 is used without LC filter, speaker inductance component reduces speaker loss in the MUTE state; therefore,
use a speaker with inductance component of 20µH or more at the carrier clock frequency.
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