This post explains for the semiconductor TA7666P.
The Part Number is TA7666P.
The function of this semiconductor is 5 Step Logarithmic Dual LED Driver.
Manufacturers : Toshiba
Preview images :
Both of the TA7666P and TA7667P consist of two inverting amplifers, the comparators and a reference voltage netwok. Turn-on level intervals are 5dB, 5dB, 3dB, 3dB, in TA7666P, and are 2dB, 2dB, 2dB, 2dB in TA7667P. It is suitable for stereo radio cassette applications because of dual type. […]