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TITLE: TUNABLE CMOS CURRENT MIRROR DESIGN
Recently we have come up with a new current mirror topology which
might be interesting for you. It will appear during the next year
in the IEEE Trans. on Circuits and Systems, Part I. If you wish,
you may already download it from SCM.PS.GZ (192K).
"Very Wide Range Tunable CMOS/Bipolar Current Mirrors with
Voltage Clamped Input"
ABSTRACT:
In low power current mode signal processing circuits it is many
times required to use current mirrors to replicate and
amplify/attenuate current signals, and to clamp the voltage of
nodes with high parasitic capacitances so that the smallest
currents do not introduce unacceptable delays. The use of tunable
active-input current mirrors would meet both requirements. In
conventional active input current mirrors stability compensation
is required. Furthermore, once stabilized, input current cannot
be made arbitrarily small. In this paper we introduce two new
active-input current mirrors that clamp their input node to a
given voltage. One of them does not require compensation, while
the other may require under some circumstances, but for both
input current may take any value. The mirrors can operate with
their transistors biased in strong inversion, weak inversion or
even as CMOS compatible lateral bipolar devices. If biased in
weak inversion or as lateral bipolars, the current mirror gain
can be tuned over a very wide range. According to the
experimental measurements provided in this paper, input current
may spawn beyond nine decades, and current mirror gain can be
tuned over 11 decades. As an application example a sinusoidal
gm-C based VCO has been fabricated whose oscillation frequency
could be tuned for over 7 decades between 74mHz and 1MHz.
Bernabe Linares-Barranco, PhD
Senior Researcher (Colaborador Cientifico) CSIC
Instituto Microelectronica Sevilla (IMSE)
National Microelectronics Center, CNM-CSIC
Ed. CICA, Av. Reina Mercedes s/n
41012 Sevilla, SPAIN
Phone: 34-95-4239923 *** NEW AREA CODE ***
Fax: 34-95-4231832 *** NEW AREA CODE ***
E-mail: bernabe@imse.cnm.es
URL: http://www.imse.cnm.es/~bernabe
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FILENUMBER: 9851
BEGIN_KEYWORDS
CURRENT_MIRROR
END_KEYWORDS
DATE: December 1998
TITLE: TUNABLE CMOS CURRENT MIRROR DESIGN
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