In the self-made power amplifier circuit, the biggest headache than the differential pair transistor circuit and zero drift, a power amplifier tube to careless also rushed … … Well now you can try TDA7250.
TDA7250 SGS-THOMSON for the company produced a power amplifier driver IC, which has the following features:
* Simple peripheral circuits, making easy;
Support for a wide voltage range: 2V-90V (± 10V-± 45V);
* Has no zero drift temperature compensation control circuit;
• Power transistor overcurrent protection;
* Mute / standby functions;
* Less power consumption;
* Low harmonic distortion: PO = 40W, fo = 1KHz THD = 0.004% when
* Output power 60W/8O, 100W/4O.
The following is the application circuit:
Circuit can be seen from the above principle is to detect over-current protection TDA7250 resistor R11, R12, R13, R14 the voltage. When the transistor over-current, in accordance with U = I · R, draw resistance increases the voltage to reach a certain voltage, TDA7250 transistor base voltage will be zero, so as to achieve the role of the transistor over-current protection. Resistors R14, R15, R16, R17 to the negative feedback loop, the gain of the circuit from the R14, R15 and R16, R17 determine the ratio, the formula GV = 1 + R14/R16 or GV = 1 + R15/R17.
The following are the PCB diagram, component diagram and sent to PCB mill arrangement for processing PCB map.