Α small audio amplifier based on the popular TDA2003 is presented here. TDA2003 requires few external components and a small heat sink to operate at normal conditions. The output power is about 6, 7.5, 10 or 12W if RL equals 4, 3.2, 2 or 1.6 Οhm respectively. The schematic is the original one provided by STMicroelectronics.

The power supply voltage must be in the range of 8-18V. The maximum operating DC voltage on the TDA2003A is 18 V, however the device can withstand a DC voltage up to 28 V with no damage. The amplifier has a low pass type response and the upper cut-off frequency is given approximately by 1/2π*R1*Cx. With C1 and R1 of about 39nF and 220Ohm, respectively, the upper cut-off frequency becomes about 19ΚΗz. C5, R3 and Cx are used for frequency stability and for avoiding oscillations in high frequencies. We strongly recommend to use the default values for these components.
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10W Audio Amplifier - TDA2003 / PCB details