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YDA143 Datasheet, PDF (11/22 Pages) YAMAHA CORPORATION – D- 3M STEREO 15W DIGITAL AUDIO POWER AMPLIFIER | |||
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YDA143
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âAllowable Dissipation
The power dissipation of YDA143 is limited by the junction temperature rating (125â) and package thermal resistance
(15.6â/W).
The power dissipation and junction temperature of YDA143 can be found by the following formula.
For the use of YDA143, take care not to exceed the power dissipation and junction temperature.
ã»Formula for the Power Dissipation
Ploss = (Pout ñ Rpn / Rl) ñ 2 + Idc ñ Vdc
Ploss
Pout
Rpn
Rl
Idc
Vdc
ï¼Allowable Dissipation (W)
ï¼Output Power (W)
ï¼0.39 (Constant)
ï¼Load Resistor (Ω)
ï¼0.040(Constant / at VDDP=12V)
0.030(Constant / at VDDP=9V)
0.045(Constant / at VDDP=13.5V)
ï¼Power supply voltage (V)
ã»Formula for the junction temperature
Tj = Ploss ñçθja + Ta
Maximum allowable dissipation of YDA143
Ploss
θja
Ta
ï¼Allowable Dissipation (W)
ï¼15.6 (Constant/ package thermal resistance (â/W))
ï¼Ambient Temperature (â)
âPackage Thermal Resistance
The package (52SSOP) for YDA143 has a Thermal Pad for radiation on the surface. Use this Thermal Pad by soldering on
a board.
The packageâs thermal resistance is 15.6â/W (4-layer board). This thermal resistance is a value measured under the
following conditions: board size 136mmÃ85mm, 1st layer and 4th layer copper foil board density 154%, 2nd layer and 3rd
layer copper foil board density 200%, no wind. In addition, the lower side pattern of the Thermal Pad is connected to all the
layers in a board by through holes (Ï0.4).
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