Radio with amplifier (CB20486E)

We found this circuit in a publication of 1991. The audio amplifier is an operational that admits equivalent.

Texas Instruments PCM5242 Audio Stereo Differential-Output DAC
Texas Instruments PCM5242 Audio Stereo Differential-Output DAC is a monolithic CMOS integrated...
Li Ion Battery Charger (CB5410E)
This single-cell Li-Ion battery charger was found in a 2005 Linear Technology manual. The circuit...
Battery Status Test (CB4581E)
This circuit has appeared on our site several times as a battery status monitor. In this...