GTL2000 Datasheet, PDF (1/2 Pages) NXP Semiconductors – 22-bit GTL processor voltage clamp

NXP bidirectional
low-voltage translators
GTL20xx
HLoewadcloinset ^{bidirectional voltage}
translation without directional control
Unlike level-shifting bus switches, which only translate between fixed voltages, these bidirectional
low-voltage translators can translate any voltage between 1 and 5 V to any other voltage between
1 and 5 V. They also reduce ON-state resistance and minimize propagation delay.
Key features
4 No directional control required for
bidirectional voltage translations
4 Low RON resistance (6.5 Ω) between
input and output pins (Sn/Dn)
4 Propagation delay: 1.5 ns (typ)
4 Channel off-state capacitance: 7.5 pF
4 Very low (5 µA) standby current
4 No power supply required – prevents
latch-ups
4 Very small QFN package options
Applications
4 Uni- and bidirectional translation for
any voltage between 1 and 5 V
4 Bidirectional translation of low-
voltage and legacy I²C-bus signals
4 Shifting processor sideband I/O
signals between GTL and LVTTL/TTL
levels
The NXP family of Gunning Transceiver
Logic (GTL) bidirectional low-voltage
translators includes the 22-bit GTL2000,
the 2-bit GTL2002, the 8-bit GTL2003,
and the 10-bit GTL2010.
Each delivers high-speed translation
between different voltage levels with
low ON-state resistance and minimal
propagation delay.
They can translate any voltage between
1 and 5 V to any other voltage between
1 and 5 V as long as there is at least 1 V
difference between the voltage levels, so
they offer greater design flexibility than
level-shifting bus switches, which only
translate between fixed voltages.
Each GTL20xx device includes NMOS
pass transistors (Sn and Dn pins) with a
common gate (G_REF pin) and a reference
transistor (S_REF and D_REF pins).
When one of the Sn or Dn ports is low,
the clamp is in the ON-state and the Sn
and Dn ports are linked through a low
ON-resistance connection. Assuming the
higher voltage is applied on the Dn port,
when the Dn port is high, the voltage on
the Sn port is limited to the voltage set
by S_REF. When the Sn port is high, the Dn
port is pulled to a higher voltage by a
pull-up resistor.
This set-up enables seamless translation
between user-selected voltages, without
the need for directional control signals.
All transistors have the same electrical
characteristics so deviation from one
output to another in voltage and
propagation delay is kept to a minimum.
The transistors also provide excellent
ESD protection in case the low-voltage
devices that are less resistant to ESD.
The translators can be used in any