DLHiFi TDA7294 70Wx2 стерео фото готовая плата

Note: This board is powered by DC and cannot be directly connected to the transformer output. A power board must be added.
TDA7294 is a high-power and high-voltage DMOS high-fidelity power amplifier IC produced by ST (SGS-THOMSON) company. It is packaged in a single-row double-row 15-pin package. VS (power supply voltage) ±10---±40V; I. (peak output power) 10A; p. (RMS continuous output power) 70W when VS=±35V 8Ω; 70W when VS=±27V 4Ω. Distortion＜0.006%.
       The design of the chip focuses on timbre, and combines the advantages of bipolar signal processing circuit and power MOS. It has the characteristics of high voltage resistance, low noise, low distortion, and the playback sound is very friendly; and has a silent standby function, short-circuit current and overheating protection functions to make its performance more complete.
Product materials:
       The PCB board is 1.6MM fiberglass board, the coupling is original brand new WIMA, the chip is original brand new, and other parts are imported brand new parts such as chemical, ELNA, ruby, Siemens, etc.
Installation and use note:
        1. The working power supply is DC voltage, which cannot be directly connected to the transformer, but must pass through the power supply board.
        2. Insulating particles and insulating sheets must be installed between the chip and the heat sink.
        3. It is recommended to use a dual 15-28V transformer with a power of not less than 100W! The impedance of the speaker is 8Ω. It is recommended that the output voltage of the transformer be double 24V. When the impedance of the speaker is 4Ω, the output voltage of the transformer is recommended to be less than double 21V, and pay attention to increase the heat dissipation area.
        4. During the power-on test, the signal input terminal on the board must be connected to the load and cannot be suspended, otherwise there will be induced noise. The signal line should be shielded as much as possible.
        5. If the board is installed in the chassis, be sure to connect the casing of the chassis to the ground wire of the input terminal on the board. If the front stage is added, the input ground of the rear stage does not need to be connected to the chassis, just connect the input ground of the front stage to the chassis. That is, if both are connected, it will cause a ground loop and generate noise.
There are several situations in which the TDA7294 is easy to burn out (burning IC) because the output end is a field effect transistor:
        1. The positive and negative voltages of the power supply are asymmetrical. If the voltage rectified by the transformer is +35V and -30V, it will burn out!
        2. Power on the IC before the capacitor is discharged, fireworks! (especially pay attention to this when DIY welding)
        3. Touch the input terminal with your hand when it is powered on, it will cause burnout!
        4. The thermal conductivity of the chip and the heat sink should be good. If the heat sink is grounded, it should be well insulated, because the IC shell is connected to negative pressure, otherwise it will burn!
        5. Wrong welding of components (such as reversed polarity welding of capacitors) may be burned out, and the output will be short-circuited by wrong connection, and it will be burned out