We found this CMOS circuit in a 1978 publication. It allows you to use a standard calculator keyboard with 16 keys for encoding in hexadecimal.
This circuit was found in an old American magazine for radio amateurs. The circuit is based on a...
The LDO series (Low Dropout) TPS80 from Texas Instruments (www.ti.com) can provide output voltages...
This circuit is from Motorola's 1990 Linear Databook. We can implement it with other operational...