The TBA120 Series ICs provide a high-gain limiting IF amplifier and a quadrature coincidence detector in one package. These ICs are primarily intended for extraction of TV intercarrier sound, which (in Europe) is frequency modulated onto a 5.5MHz or 6MHz subcarrier. The TV waveform constitutes an extreme interfering signal, and the TBA120 provides superior performance in comparison to early Foster-Seeley and Ratio Detector systems, with a considerable reduction in component count.

The ISD2500 ChipCorder family of ICs from Winbond contains almost all the necessary hardware in a single IC to record and playback audio messages. Included on the IC is a microphone preamp and AGC suitable for a low-cost electret type microphone, an output amplifier to drive a loudspeaker, memory, an oscillator, an A/D and a D/A converter. There are four basic models; 2560, 2575, 2590 and 25120, the numbers following 25 indicate the available recording time in seconds. The memory capacity of each version is actually the same but longer recording times are achieved by using a lower sampling rate. The chip with the shortest recording time therefore offers the best audio quality.

Nokia 3310 troubleshooting manual guide table of contents:

The circuit diagram of the power meter stands out by its simplicity, which is due to the Type AD8307 monolithic demodulating logarithmic amplifier, IC1, from Analog Devices. A power meter or RF decibel is an indispensable instrument in any radio workshop. With AD8307, a low-cost DC–500 MHz, 92 dB logarithmic amplifier that enables an accurate, not too expensive RF decibel meter to be constructed.