AUDIO_POWER_BOOSTER

Published:2009/7/13 1:37:00 Author:May | From:SeekIC

The audio power booster is based on two TDA2006 audio IC power amplifiers. Power amplifier IC1 is used as what is virtually a noninverting amplifier, with the noninverting input of the device beirtg biased to half the supply voltage by R2 and R3. R5 provides 100-percent negative feedback from the output to the inverting input of IC1 at dc so that the circuit has unity voltage gain and the output is biased to the required level of half the supply voltage. C2 and R4 remove some of the feedback at audio frequencies, and this gives a voltage gain of about 18 times at these frequencies. R1 is used at the input of the amplifier to reduce the sensitivity to a more suitable level, and C1 simply provides dc blocking at the input. IC2 is used in virtually the same configuration, but its noninverting input is not fed with an audio signal and it only receives the dc bias signal from R9 and R10. Resistor R11 couples the output signal of IC1 to the invertinginput of IC2, and the value of R11 is chosen to give IC2 an effective voltage gain of unity. However, as the input signal is coupled to IC2's inverting input, there is a phase inversion through this section of the amplifier, giving the required antiphase relationship at the two outputs. Diodes D1 to D4 are protection diodes for the two ICs, while R6 plus C4 helps to prevent instability. Components C3, C5, and C7 are all supply decoupling capacitors.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Basic_Circuit/AUDIO_POWER_BOOSTER.html

Print this Page | Comments | Reading(3)