The integrated circuit used in this 70's application is not common today. The circuit consists of a small audio amplifier with few external components.
Combining an Ultra-Low Power MCU with an 802.15.4 Radio, the SAM R30 Enables Long-Lasting Battery...
This comparator with two Texas Instruments operators was obtained in a company application manual....
August 2017 - Mouser Electronics already has the Connect One Pico WiReach ™ SMTS Pico modules...