YDA131 Datasheet, PDF (10/18 Pages) YAMAHA CORPORATION – D- 1 STEREO 2.5W DIGITAL AUDIO POWER AMPLIFIER

YDA131
If power supply voltage changes exceeding 10% in a very short period, this IC may go into mute state internally due to
the pop moise reduction function described before. Therefore, it is recommended to use this IC in normal operation so
that the change of power supply voltage in a very short period wouldn't exceed 10%.
This IC may also go into mute state internally when the power supply voltage is reduced temporarily below 3.0V.
Therefore, it is recommended to use this IC in normal operation so that the power supply voltage wouldn't fall below
3.0V.
●Power consumption
This IC is capable of outputting up to 5W in total, or 2.5W per one channel. Digital amplifiers can be used without heat sink
because their operation efficiency is higher than conventional linear amplifiers.
When using this IC, ensure that the power consumption does not exceed the maximum allowable loss that is defined as the
absolute maximum rating.
The power consumption of this device can be obtained by using "Formula 5".
In the following formula, PD represents the power consumption, Po represents average output power, RL represents the
output load impedance, and Pic represents the internal control circuit loss.
Formula 5: PD(W) = Po(W) * 1.05 / RL(Ω) + Pic(W)
Pic = 0.09W (VDD=5.0V)
Pic = 0.04W (VDD=3.3V)
The maximum allowable loss PDmax is obtained by using "Formula 6" based on the absolute maximum rating of the
junction temperature of this IC.
In the following formula, Tjmax represents the absolute maximum rating of the junction temperature, θja represents thermal
resistance of SSOP24 package, and Ta represents the ambient temperature.
Formula 6: PDmax(W) = (Tjmax(°C) - Ta(°C)) / θja
θja = 96.7°C/W
Tjmax = 125°C
For example, when VDD=5.0V, output load=4Ω, and 2.5W * 2ch is outputted continuously, the maximum allowable loss is
exceeded. However, this IC can deal with reproduction of normal music signal sources sufficiently because it is believed to
be sufficient that average output power of the normal music signal sources is estimated at 1/8 of the maximum output.
●Load impedance and filter constant
The speaker that is connected to this IC is to have the load impedance (RL) of 4Ω or higher.
Typical filter constants for load impedance (RL) when the cut-off frequency is set at 50kHz are as shown in the following
table.
Table: Filter constant example
Load impedance RL
L
4Ω
10μH
8Ω
22μH
16Ω
39μH
C
1μF
0.47μF
0.27μF
10