The maximum number of separate digital inputs that can be connected to a logic gate without degrading its performance. Gates with a large number of inputs require complex internal transistor arrangements, which increases propagation delay and input capacitance. When a circuit requires more inputs than a standard gate provides, designers must cascade multiple gates together.
Heard on the job
We can't use a single NAND gate here because the fanin requirement is eight, and our standard cell library only goes up to four.
Also heard as
- fan-in
Do not mix it up with
- Fanout: Fanin dictates how many inputs a gate can receive, whereas fanout dictates how many subsequent inputs a gate's output can drive.