AUTOMATIC HIGH FREQUENCY CONTROL CIRCUIT FOR A MOBILE PHONE

摘要

The circuit for controlling the output level of car phone comprise: an amplifier (2) amplifying the high frequency output signal applied from the coupler; an analog switch (5) outputting the amplified high frequency signal as level signal appointed from CPU; a comparator (4) providing the comparative output from the output signals of analog switch (5) and amplifier; a transistor array (9) transfering the output signal of comparator to the final output terminal amplifier (10); a bar graph IC (20) applying the output signal of amplifier (2), which is converted to signal corresponding to level of log step, to each input terminal of analog switch.