文档介绍：A Dual-Base Triggered SCR with Very Low Leakage
Current and Adjustable Trigger Voltage
James
Di
Sarro
(1),
Vladislav
Vashchenko
(2),
Elyse
Rosenbaum
(1)
and
Peter
Hopper
(2)
(1)
University
of
Illinois
at
Urbana
Champaign,
1308
W.
Main
St.,
Urbana,
IL
61801
(2)
National
Semiconductor,
Santa
Clara,
CA
95052
Abstract
–
A
new
dual
base
triggered
SCR
is
presented.
By
adjusting
the
device
sizings
in
the
trigger
circuit,
the
designer
sets
the
trigger
voltage
to
an
application
appropriate
value.
The
turn
on
time
parable
to
that
of
DTSCRs
fabricated
in
the
same
technology
node,
but
the
leakage
is
orders
of
magnitude
lower.
I. Introduction
High
frequency
I/O
pins
require
low
capacitance
ESD
protection
circuits;
for
applications
in
which
the
dual
diode
protection
circuit
cannot
be
used,
SCR
based
solutions
provide
the
highest
level
of
protection
per
unit
capacitance.
Trigger
circuits
are
needed
to
turn
on
SCRs
quickly
and
at
sufficiently
low
voltages.
The
DTSCR
[1]
and
GGSCR
[2],
which
are
shown
in
Figs.
1
and
2,
respectively,
are
suitable
for
protecting
low
voltage
I/Os.
The
DTSCR
is
favored
over
the
GGSCR
because
its
trigger
voltage,
Vt1,
is
easily
adjusted
by
altering
the
number
of
diodes
in
the
trigger
circuit.
Additionally,
in
advanced
technology
nodes,
special
process
steps,
.
sili