The stochastic I-Pot: A circuit block for programming bias currents

In this brief, we present the “Stochastic I-Pot.” It is a circuit element that allows for digitally programming a precise bias current ranging over many decades, from pico-amperes up to hundreds of micro-amperes. I-Pot blocks can be chained within a chip to allow for any arbitrary number of programm...

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Detalhes bibliográficos
Autores: Serrano Gotarredona, Rafael, Camuñas Mesa, Luis Alejandro, Serrano Gotarredona, María Teresa, Leñero Bardallo, Juan Antonio, Linares Barranco, Bernabé
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2007
País:España
Recursos:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/77503
Acesso em linha:https://hdl.handle.net/11441/77503
https://doi.org/10.1109/TCSII.2007.900881
Access Level:acceso abierto
Palavra-chave:Analog circuits
Current-mode circuits
Current biases
Low-power circuits
Descrição
Resumo:In this brief, we present the “Stochastic I-Pot.” It is a circuit element that allows for digitally programming a precise bias current ranging over many decades, from pico-amperes up to hundreds of micro-amperes. I-Pot blocks can be chained within a chip to allow for any arbitrary number of programmable bias currents. The approach only requires to provide the chip with three external pins, the use of an external current measuring instrument, and a computer. This way, once all internal I-Pots have been characterized, they can be programmed through a computer to provide any desired current bias value with very low error. The circuit block turns out to be very practical for experimenting with new circuits (specially when a large number of biases are required), testing wide ranges of biases, introducing means for current mismatch calibration, offsets compensations, etc. using a reduced number of chip pins. We show experimental results of generating bias currents with errors of 0.38% (8 bits) for currents varying from 176 A to 19.6 pA. Temperature effects are characterized.