TDA3050 データシートの表示（PDF） - STMicroelectronics
部品番号
コンポーネント説明
メーカー
TDA3050 Datasheet PDF : 4 Pages
| |||
an inductor may be needed in series with the output to prevent instability with capacitive loads
(10 turns of 0.5mm wire wound around a 10 Ohm 1W resistor). The most common capacitive
load is the speaker cable itself, and 'audiophile' leads are often worse than standard grade
cables in this respect.
The 1 Ohm resistor (R6) should be a 1W or 0.5W type, and all others should be 1/4W 1% metal
film (as I always recommend). All electrolytic capacitors should be rated at 50V if at all possible,
and the 100nF (0.1uF) caps for the supplies should be as close as possible to the IC to prevent
oscillation. C1 should be a bipolar (non-polarised) electrolytic, or may be plastic film if you
prefer.
The supply voltage should be about ±25 Volts at full load, which will let this little guy provide a
maximum of 25 Watts (rated minimum output at 25°C). To enable maximum power, it is
important to get the lowest possible case to heatsink thermal resistance. This will be achieved
by mounting with no insulating mica washer, but be warned that the heatsink will be at the -ve
supply voltage and will have to be insulated from the chassis. For more info on reducing thermal
resistance, read the article on the design of heatsinks - the same principles can be applied to
ICs - even running in parallel. I haven't tried it with this unit, but it is possible by using a low
resistance in series with the outputs to balance the load.
Note that the supply voltage must not exceed ±30V at any time - this is the absolute maximum
voltage rating for the LM1875. Note that the TDA3050 is rated for a maximum of ±25V.
Figure 2 - IC Pinouts
Figure 2 shows the pinouts for the LM1875, and it should be noted that the pins on this device
are staggered to allow adequate sized PCB tracks to be run to the IC pins.
The PCB for this amp is for a stereo amplifier, is single sided, and supply fuses are located on
the PCB. The entire stereo board including four fuses is 115mm x 40mm (i.e. really small). The
heatsink needs to be bigger than you might expect, largely because of the relatively high
thermal resistance of the TO-220 case. National recommend that the heatsink should be no
smaller than 1.2°C / Watt (it is actually suggested that the heatsink be 0.6°C / W, but this is a
very large heatsink indeed, and is not necessary for normal audio into reasonably well behaved
loads.
Share Link: 