74VCX163245
Product Page
74VCXHQ163245 is a new quiet Level Translator that allows
very low EMI, parallel communication between the baseband
processor and the colour display.
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The latest addition to ST’s VCX product line is the
Level Translator IC, 74VCXHQ163245. It is a dual supply
low voltage CMOS 16-bit Bus Transceiver fabricated with
sub-micron silicon gate and five-layer metal wiring C2MOS
technology.
This IC is intended for two-way asynchronous communication
between data buses and the direction of data transmission
is determined by nDIR inputs.
The enable inputs nG can be used to disable the device so
that the buses are effectively isolated.
It is designed for use as an interface between a 3.3V bus
and a 2.5V or 1.8V bus in a mixed 3.3V/1.8V, 3.3V/2.5V or
2.5V/1.8V supply system.
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74VCXHQ163245
logic diagram |
All inputs
are equipped with protection circuits against static discharge,
giving them 2kV ESD immunity against transient excess voltages.
All floating bus terminals during high impedance state do
not need any external pull-up or pull-down resistors.
74VCXHQ163245 is characterized for operation over the commercial
temperature range of -40°C to + 85°C.
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| Innovative
µTFBGA42 Package |
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The 74VCXHQ163245 addresses rapidly evolving customer
requirements for more circuit integration and board miniaturization
with the new lead-free µTFBGA42 package (RoHS Compliant
– Restriction on Hazardous Substances). The device
packaging is specially designed with minimum dimensions
to suit the space-constrained implementation like in mobile
phones. It is packaged in an innovative lead-free µTFBGA42
package with a pitch of 500mm and dimensins of 4mm x 3.5mm.
It is also available in regular TSSOP48 and TFBGA54 packages.
It will be shipped in standard tape and reel form with
3000pcs per reel.
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 High speed: tPD = 7.7ns (max)
at VCC A = 2.8V; VCC B = 1.8V; B n
to A n;
Low power dissipation: ICC A
= ICC B = 20µA (maximum);
Power down protection on inputs
and outputs;
Series resistor on A side;
Limited EMI noise: tr A
approx. tf B > 4ns at C L = 10pF;
Operating Voltage Range:
V CCA(OPR) = 2.3V to 3.6V;
V CCB(OPR) = 1.65V to 3.6V;
Bus Hold provided on data
inputs on both sides;
ESD performance: HBM >
2000V (MIL STD 883 method 3015); MM > 200V;
Lead-free µTFBGA package.
| 74VCXHQ163245
Functionality |
Applications include a wide variety of systems that must interface
with new, lower voltage technologies and legacy designs operating
at a higher voltage level.
This device provides a bi-directional interface for buses operating
at mixed voltage levels in the range of 1.4V to 3.6V, giving true
signal translation with very low EMI. This feature makes it suitable
as a display interface to connect the baseband processor with
the display controller.
Application block diagram
Such a device is required as the signals of the two end devices
are at different voltages. 74VCXHQ163245 supports designs with
the A side inputs at a higher voltage potential (3V/2.8V) than
the B side (2.8V/1.4V). In this way it provides a quick and easy
direct interface between the mixed voltage levels present in the
same system.
For instance, in the above example it interfaces between the 1.4V
baseband processor and the 2.8V display controller.
A need for this device can be found in all forms of telecommunications,
portable computers, mobile phones and PDAS. In fact, these applications
use mixed voltage levels extensively to maximize power savings
by using 1.4V/1.8V wherever possible and 2.5V/3.3V only where
necessary.
The series resistor on the higher voltage side, dampens the reflections
due to impedance mismatches. This ensures reliability of the signal
even when long signal traces are used. Typical ICC A
and ICC B are very low (around 2µA at 25°C).
This is a very important consideration for mobile phone applications
where battery life should be extended as much as possible.
Minimal overshoot even at high speeds
EMI is reduced by controlling the slew rates and also by using
minimum-current output drivers. Thus 74VCXHQ163245 achieves high
speed operation while maintaining the low CMOS power dissipation
and limited rise and fall time (low EMI). This is particularly
suited for display interfaces in mobile applications where the
EMI at high speeds is a critical issue. |
