A high-precision current-mode WTA-MAX circuit with multichip capability

This paper presents a circuit design technique suitable for the realization of winner-take-all (WTA), maximum (MAX), looser-take-all (LTA), and minimum (MIN) circuits. The technique presented is based on current replication and comparison. Traditional techniques rely on the matching of an N transist...

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Detalhes bibliográficos
Autores: Serrano Gotarredona, María Teresa, Linares Barranco, Bernabé
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:1998
País:España
Recursos:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/76430
Acesso em linha:https://hdl.handle.net/11441/76430
https://doi.org/10.1109/4.658631
Access Level:acceso abierto
Palavra-chave:Analog circuits
Analog computation
Currentmode circuits
Maximum circuits
Transistor mismatch
Winner-take- all
Descrição
Resumo:This paper presents a circuit design technique suitable for the realization of winner-take-all (WTA), maximum (MAX), looser-take-all (LTA), and minimum (MIN) circuits. The technique presented is based on current replication and comparison. Traditional techniques rely on the matching of an N transistors array, where N is the number of system inputs. This implies that when N increases, as the size of the circuit and the distance between transistors will also increase, transistor matching degradation and loss of precision in the overall system performance will result. Furthermore, when multichip systems are required, the transistor matching is even worse and performance is drastically degraded. The technique presented in this paper does not rely on the proper matching of N transistors, but on the precise replication and comparison of currents. This can be performed by current mirrors with a limited number of outputs. Thus, N can increase without degrading the precision, even if the system is distributed among several chips. Also, the different chips constituting the system can be of different foundries without degrading the overall system precision. Experimental results that attest these facts are presented.