1-Bit BJT NOR Full adder

Implementation of a single bit adder using NOR gates made of BC547 BJT’s. Simple circuit that shows advantage of NOR gates over NAND in both lower supply and better base voltage control over both transistors in NOR topology. Propagation delay:~3ns - with ideal components. Likewise results can be achieved by replacing transistors with faster ones (Bfr93A for an instance) or by adding circuitry that prevents transistors from completely turning off as it takes a lot of time (up to 250ns in case of Bc547) Supply voltage: 0.7 - 3V (depends on transistors used) Here is a chart for power consumption from my testing IRL (100R resistors are used instead of 20R): 0.71V - 20mW 0.82V - 33mW 0.9V - 43mW 1V - 56mW 1.2V - 88mW 1.5V - 143mW 1.8V - 210mW 2.1V - 290mW 2.4V - 400mW

published 8 years ago